2003 chevy astro blower motor

Hi, I have a 2003 chevy astro that the blower motor doesn't work on high. All the other settings work. Any ideas??

Thanks.

I removed the washer and coolant res to get to the resistor pack. I took it apart and found that the plug melted a little on the high speed side. I cleaned it up and plug back in. Works fine. Hope that does the trick. Thanks for the location of pack in otheer threads. Help out a lot. :grinyes:

I'm having the same problem with my '98. I've replaced the switch as well as the resistor but still no blower on high. When I first replaced the resistor it started working perfect in the gaarage so I figured problem solved. The next day after about 15 minutes of running on high it just stopped all other fan settings work. Then I replaced the switch. Still no blower on high. I hate to replace the blower as it seems electical. Any thoughts would be appreciated.

On a side note, the replaced resistor was taken off another '98 from a junk yard (trying to save a little) so I'm not sure if this is contributing to bad connection?

There are 2 orange wires in the electrical connector at the resistor pack: The larger one must show battery voltage at all times. The smaller one must show battery voltage with the key on and the blower switch in the high speed position. Post your results.

I did check the wires and the larger red wire checked at 12v and the smaller orange did not register. Funny thing was when I inserted the probe in the resistor to get a reading I had the fan on high and it kicked on. I started wiggling the red wire and the fan would kick on and off. I pulled the resistor to examine closer and notice the connection where the larger red wire is looks burnt. The male connector may be fried ? I'm thinking to go to the local junk yard and pull a wire harness and splice in? Certainly does not seem like a blower motor.

Common problem to burn at the connector to the relay/resistor. While you're at the boneyard, might as well get the resistor AND the harness connector. Do yourself a favor and solder the connector on, don't use crimp connectors.

Another option is to bypass the relay and install an external 40amp relay They're about $5 and a couple feet of wire, a few terminals, 20 minutes time and you're done. If you need directions on how to do it, just ask.

I have been trying to get this annoying fan issue resolved for a while (low priority). The discoveries today were awesome. Fingers crossed. The beauty of this is SANTA brought me soldering gun this year and now I have an oportunity to use. Thanks. I will post results.

pretty cold in Lansing, gonna need that blower. Say Hi to Jennifer and wish her farewell for me if you see her ;)

Make sure you use 60/40 lead/tin rosin core solder.

I finally completed the electrical connector replacement and and the blower works great... finally. I soldered the wires and shrink wrapped the spliced wires. Thanks for all the help.

Hello I have the same problem, ho fan on HI. It appears the connector on the Big orange wire is burnt/corroded I would like to by pass or may need a new reelay. ...old_master I was hoping you could let me know how how to add a relay as you spoke about in the post ..it would be appreciated.

Hello I have the same problem, ho fan on HI. It appears the connector on the Big orange wire is burnt/corroded I would like to by pass or may need a new reelay. ...old_master I was hoping you could let me know how how to add a relay as you spoke about in the post ..it would be appreciated.

What year and model is your vehicle?

It is a 2003 GMC Safari. Fan works except on Hi. If I understood correctly it may be a relay problem? Pulled the resistor assembly out earlier today and the connector is slightly melted on the first pin (Large fage orange wire 12Volts). but fan does work at lower speeds.

thanks in advance for your help

First, make sure the small orange wire at the resistor/relay has battery voltage with the key on, mode switch on heat, and the blower switch in the high position.

How to bypass the OEM high blower relay

You’ll need a relay, some 14 gauge wire, a few terminals, a soldering gun, rosin core solder, electrical tape, and about 15 minutes of time.
Most auto parts stores carry the terminals, and relays that are rated at 40 amps that look similar to this for around $5 USD:
http://i561.photobucket.com/albums/ss58/cwhook/relay.jpg
Mount the relay to a secure spot under the hood near the heater blower motor so that it will not interfere with anything. On the Astro Safari, there is a flat spot on the firewall just above the blower motor that works well. The terminals should be facing down so water will not enter the relay. There are 5 terminals on the relay, only 4 of them will be used to bypass the high blower relay.
To make the wire harness for the relay, you’ll need four 14 gauge pieces of wire about 18” long. On one end of each wire, solder on a female spade terminal.

http://i561.photobucket.com/albums/ss58/cwhook/Femalespadeterminal.jpg
On one of the 4 wires, solder an eyelet terminal on:
http://i561.photobucket.com/albums/ss58/cwhook/eyeletterminal.jpg

You should now have three 18” wires with a female spade terminal on one end of each wire. You should also have one 18” wire with a female spade terminal on one end, and an eyelet terminal on the other end.
Attach the eyelet terminal to body ground, near the relay, using a screw. Connect the other end to the relay terminal #86. There are 2 orange wires going to the original blower resistor/relay. Cut both of them close to the electrical connector. Using one of the 18” wires, solder it to the larger orange wire and connect it to relay terminal #30. Using another 18” wire, solder it to the smaller orange wire and connect it to relay terminal #85. Using the last 18” wire, connect it to relay terminal #87. At the blower motor there is a purple wire, don’t cut the wire, strip a section long enough to solder the wire from relay terminal #87.

Neatly tie up the wires so they don’t interfere with anything, and you’re done.

Any questions, just ask.

Pretty straight forward... I just need to go get a relay and connectors Yes there is power to the small orange wire when switch is in the high position. No purple wire to the fan ...just red and black, The red carries the power so I'll splice into that one.
Thanks a lot for the instructions!

OEM feed wire was purple, could be the resistor has been replaced, probably due to a bad relay ;) Red wire should be the one you need, make sure it has battery voltage with the blower on, or you'll toast the new relay. When you get done with the bypass, the replacement relay is far more substantial and should outlast the vehicle. Keep us posted.

Found a relay and harness all in one for $5.99. A little solder and shrink wrap tubing and the fan works like a charm!

Now on to the seconded issue. The systems keeps blowing air to the floor and won't switch to the dash vents. I found a one end of broken vacuum hose (small very thin plastic) under the hood, attaching to a rubber hose.... I guess I just have to hunt around for the end it broke off of and replace it. Too late to look tonight..that's one for another day.

Thanks again.

Glad you got the blower working. The HVAC air distribution defaults to the defrost position when there is a loss of vacuum to the control switch in the dash. You might have two problems going on. The HVAC gets vacuum through a small black plastic vacuum line that runs from the PCV valve on the driver side rocker arm cover, across the front of the engine to a vacuum reservoir below the washer reservoir, (inside the RF fender). From the reservoir ir runs to the control switch. There is a vacuum check valve/vacuum tee inline near the top of the A/C accumulator. Best to trash the entire plastic line and run new rubber line to repair it.

Actually got it fixed soon after posting... A visual inspection found the other end.

I cut back both ends to get rid of any cracks. Murphy was on my side for once and I found a piece of tubing the fix very snugly over the newly cut end and it worked like a charm. Will probably get some new tubing as you suggested but this will work until a get a chance to. Thanks again for all the help and advice.
I am sure it would have cost a least a couple of hundred dollars more if I took it in for the service!

Some additonal photos (hope you can see 'em) and thanks, again, to the Old Master!

gramps

http://www.briteblueball.com/resources/Astro+Blower+02.jpghttp://www.briteblueball.com/resources/Astro+Blower+01.jpg

Hi there,

Very nice and detail instructions. I'm new to this forum and newbie from an auto repair perspective as well.
I have a similar problem with a 99 Astro. The fan switch on AC all works except on the last (right most) tic, high. When I switch there, fan is out. Can you let me know if your instruction here would apply to my Astro? Sound like I'm having the relay issue? If you can let me know exactly where it is located that would be great. I can never find a instruction or manual where all the parts supposed to be located. I have this problem "fixed" not long ago (maybe 1.5 years) and it cost me $200. I asked about what was replaced, but I really didn't get an answer so I don't think I'm taking it back again. I rather try to replace it myself if it's "simple" as it indicate here. Thanks in advance.

Hi there,

Very nice and detail instructions. I'm new to this forum and newbie from an auto repair perspective as well.
I have a similar problem with a 99 Astro. The fan switch on AC all works except on the last (right most) tic, high. When I switch there, fan is out. Can you let me know if your instruction here would apply to my Astro? Sound like I'm having the relay issue? If you can let me know exactly where it is located that would be great. I can never find a instruction or manual where all the parts supposed to be located. I have this problem "fixed" not long ago (maybe 1.5 years) and it cost me $200. I asked about what was replaced, but I really didn't get an answer so I don't think I'm taking it back again. I rather try to replace it myself if it's "simple" as it indicate here. Thanks in advance.

Post #13 applies to your 99 Astro as well. The modification will bypass the OEM relay and upgrade to a much more substantial relay.

Hi old_master,

Point of clarification, in #13:
"First, make sure the small orange wire at the resistor/relay has battery voltage with the key on, mode switch on heat, and the blower switch in the high position."
To take the voltage measurement, I should place the red (+) probe (from meter) to the orange wire, and the black probe (-) to the car chassis? The reading could be anything >= 12 volt?
Thanks advance for your response.

That is correct, and your meter should indicate battery voltage.

In need of some help. I also around 8 months ago had a connector that was burned on Pin 1 (Thick Orange) and Pin 3 (Black-ground I believe).
I replaced the blower motor resister and bought a new connector PT1134 and soldered it to harness. Everything worked great until yesterday.
I pulled the connector and it has burned at pin 3 (Black-Ground) and I am puzzled :shakehead on what can be causing this failure
If anyone can help I would greatly appreciated. Thanks

High resistance in either the blower motor, or the blower motor ground near the motor, is what's causing the wiring to burn.

Thanks for the reply. I recall also replacing the blower motor with connector and resistor as well. Do you happen to know location of blower motor ground near the motor and how to test? Thank you for your time.

There are two wires at the blower motor: The negative, (ground) wire goes to the body of the vehicle. Follow it as it leaves the motor, it will be a short wire and have an eyelet terminal with a bolt in it grounding it to the body of the vehicle. The connection must be clean and tight.

Thanks again for the reply. The Only wires I see coming from the blower motor is the connector (red and black) that connects to the blower motor resistor. From there is the Main 6 pin connector.
If the Follow the Harness a good 30 inches or so I see an eyelet terminal to body. I checked connection from blower motor connector to blower motor resistor pin. then to
main connector pin 3 and then to ground eyelet and everything seems ok??

At the blower motor harness connector, check resistance on the black wire to a good clean chassis ground, must be less than 5 ohms.

http://i561.photobucket.com/albums/ss58/cwhook/2002AstroSafariBlowerSchematic.gif

OldMaster,

Checked the connector to ground. Reading was 00.3 ohms.

Check amperage draw of the blower motor using the terminals on the motor itself, (bypass the vehicle harness). Post your result.

Common problem to burn at the connector to the relay/resistor. While you're at the boneyard, might as well get the resistor AND the harness connector. Do yourself a favor and solder the connector on, don't use crimp connectors.

Another option is to bypass the relay and install an external 40amp relay They're about $5 and a couple feet of wire, a few terminals, 20 minutes time and you're done. If you need directions on how to do it, just ask.

Hi Old_Master, I too have the same issue and going to take your Great advise and By Pass with Relay. I was wondering if the vehicle is safe to drive with this electrical issue going on, just wondering if this can effect the other components in anyway?

I lose A/C when i'm driving up a bridge, like it loses power, still working but nothing coming out of vents until i get over the top of bridge. What could cause this? It's a 2000 Chevy Astro Van, Thanks in Advance.. :)

Best to repair it. If the connector is melted, heat caused it.... where there's smoke, there's fire ;)

The issue with air flow is caused by a leak in the HVAC vacuum system. Common problem is the source line where it crosses the engine in front. Dry rots or burns.... needs new vacuum line ;)

Here is a Pic of mine, just finished, works great but now it only is blowing through the defrost.

Relay looks good! Follow the vacuum line, next to the relay, back to the intake manifold on the driver side, (next to the throttle body). I think you'll find a rotten vacuum line or it came loose.

Relay looks good! Follow the vacuum line, next to the relay, back to the intake manifold on the driver side, (next to the throttle body). I think you'll find a rotten vacuum line or it came loose.

Thanks, what happened i was just checking it with the key in the forward position and not with the van running, it was only blowing in de-frost mode. When i started it up to move it out of garage, it was working fine.. I'm guessing the engine needs to be running for vacuum?

The HVAC system uses vacuum to operate the water valve, blend & mode doors, however, there is a check valve near the AC accumulator that is supposed to keep HVAC vacuum in the HVAC system. If there are no leaks in the HVAC system, and the mode switch is not moved, vacuum should hold the doors in the same position, even when the engine is off.

Here is a Pic of mine, just finished, works great but now it only is blowing through the defrost.

Ronnie,

Your wiring looks really great and professional. If you have pictures of where the wires are spliced into the wires to the connector and to the wire from the blower motor, can you post those, too? I'm better with pictures. Thanks :)

The HVAC system uses vacuum to operate the water valve, blend & mode doors, however, there is a check valve near the AC accumulator that is supposed to keep HVAC vacuum in the HVAC system. If there are no leaks in the HVAC system, and the mode switch is not moved, vacuum should hold the doors in the same position, even when the engine is off.

Thanks.. I found the check valve but it is a 3 way, can't seem to find it anywhere, O'Reilly's, Rock Auto ?? Would you happen to know the P/N or where to find it ?

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_two-way-check-valve--gm-2008-83-dorman--help_17190329-p?searchTerm=vacuum+check+valve

The cone shaped single fitting goes toward the engine.

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_two-way-check-valve--gm-2008-83-dorman--help_17190329-p?searchTerm=vacuum+check+valve

The cone shaped single fitting goes toward the engine.

Thank You SO Much, you are such Great help : ) Really appreciate you:smile:

HI Old Master, sorry to pester you but maybe you could help.

I found this thread along time ago and just now found this again after a lot of searching and finally found it again!!!!!!!!!!!!! Woooo hooo!

So if your still around and have time I'd sure appreciate your advice, so here goes.

I have a 96 Chevy Astro and I only have one orange wire.
No Purple wire at all like the other feller from a couple posts up...

Color of wires are from left to right on resistor are as follows...

Red fat wire... Little Orange wire...Black Fat wire...Little Light-Brown wire...Little Yellow wire...and a Little blue wire.

From the bottom of the resistor are two wires that go to the blower motor. They are Red and Black.

I'd sure like to fix this thing soon if I could but I really aint about cutting wires with out knowing which to cut.

Either way....thanks for figuring out this by-pass and I hope you got time to respond.

Thanks!

JimB000OOOooo...

The wiring on your 1996 Astro is different from the 2003 explained above. Here is how to bypass the high blower relay on your 1996:

On the add-on relay:
Terminal #86 goes to ground.
Cut the orange wire at the blower resistor and connect it to terminal #85.
Cut the red wire at the blower resistor and connect it to terminal #30. You need to use 10 gauge wire to extend it.
Splice a 10 gauge wire on to the red wire that goes to the blower motor, (do not cut the red wire) and connect the other end to terminal #87.

Hey Old Master ,

Thank you for the reply. I figured that was how it was with the orange and red wire. I checked voltage and it seems to be the red wire is HIGH and the orange wire is Med-High.

Only thing is... I just now this very minute... just hooked it all up and I used the 14 gauge wire. OH NOOOOOOOOOOOoooooooooooooooooo......... too impatient I reckon.

It all seems to be working except the HIGH though still. Maybe the bigger gauge wire is what needs to be changed and might fix it....either way I've got to redo all this now to the 10 gauge.

If it dont work after that I suspect it might be the switch on the dash cause I've changed everything else. Checked voltage, ground , replaced blower motor, voltage resistor, voltage resistor harness etc....

Again thank you for your help! Your the man!


JimB000OOOooo...

Hi Old Master, Need help finding the other end of vacuum line on 2003 Astro. facing front end of vehicle, found line running from left, passenger side, to right over air intake going back & down toward driver side, rubber tube with broken smaller hard plastic tube inside just hanging. Where is the other end? can i get to it from the outside of vehicle or do i need to remove the doghouse? Thanks in advance for your assistance and photo if available.

Hi Old Master, Need help finding the other end of vacuum line on 2003 Astro. facing front end of vehicle, found line running from left, passenger side, to right over air intake going back & down toward driver side, rubber tube with broken smaller hard plastic tube inside just hanging. Where is the other end? can i get to it from the outside of vehicle or do i need to remove the doghouse? Thanks in advance for your assistance and photo if available.

You'll need to remove the engine cover, (dog house) to access the vacuum fitting, (driver side of engine). If the fitting is broken, try a boneyard, dealer or auto parts store. The black plastic housing, (#3) must be turned ~1/4 turn to remove it from the plenum. The vacuum line goes to #4:
http://i561.photobucket.com/albums/ss58/cwhook/mxiga039amu_gm_intake_manifold_zps6e2dc7dd.jpg

Thank you so much for the quick reply and the photo IS worth a thousand words. I appreciate you so much!

The image is actually a 1996 or newer 4.3L in a Blazer, so your 03 Astro 4.3L black plastic housing may look slightly different, but the function is the same.

Good to know, thanks again.

Mission accomplished. Thanks again for your help!

Glad we could help, thanks for posting back!

This is golfbum, I tried your fix for the now power on the high setting. I installed the
relay as described it did not work. I check the power on the two orange wires. The large on had battery voltage the small one did not. I check ohm on the small one it
was about 5. Any ideas.
golfbum

I know this is in response to a old thread, but my 2002 Safari van with rear air has this issue. And are very knowledgeable with this issue and how things really work
I have had to replace the resistor several times since I purchased with 5,000 miles, it now has 166,000. Each time, also had to replace the socket as the large orange socket was burnt. So if possible I would like to remove that problem.

Does this relay bypass only the high fan? if no, is there a way to ONLY bypass the High? as that is the highest amp draw which causes burnt connections, especially when there is a grounding or motor failure problem.

I would figure you disable the resistor completely, since you remove the 12v source (large Orange wire) in your relay application. unless it back feeds on the red wire from the fan.

The mod will bypass the OEM high speed blower relay.

I have the same "high setting" issue with my A/C. We replaced the connector to the resistor because of all the burns we had seen on it. All wires soldered&heat shrinked and everything.
Also, replaced the blower motor and the fan resistor .
Our mechanic had stated that there is no power going to the "thick" wire. Ive seen everyone say to check if theres power going to it and there is not.
How do we even solve this issue without bypassing , or jerry rigging anything. I am not too good with mechanic work, nor electrical issues. But its really hot out now and our astro is our work horse and we need it fixed asap. Thanks

First, make sure the small orange wire at the resistor/relay has battery voltage with the key on, mode switch on heat, and the blower switch in the high position.

How to bypass the OEM high blower relay

You’ll need a relay, some 14 gauge wire, a few terminals, a soldering gun, rosin core solder, electrical tape, and about 15 minutes of time.
Most auto parts stores carry the terminals, and relays that are rated at 40 amps that look similar to this for around $5 USD:
http://i561.photobucket.com/albums/ss58/cwhook/relay.jpg
Mount the relay to a secure spot under the hood near the heater blower motor so that it will not interfere with anything. On the Astro Safari, there is a flat spot on the firewall just above the blower motor that works well. The terminals should be facing down so water will not enter the relay. There are 5 terminals on the relay, only 4 of them will be used to bypass the high blower relay.
To make the wire harness for the relay, you’ll need four 14 gauge pieces of wire about 18” long. On one end of each wire, solder on a female spade terminal.

http://i561.photobucket.com/albums/ss58/cwhook/Femalespadeterminal.jpg
On one of the 4 wires, solder an eyelet terminal on:
http://i561.photobucket.com/albums/ss58/cwhook/eyeletterminal.jpg

You should now have three 18” wires with a female spade terminal on one end of each wire. You should also have one 18” wire with a female spade terminal on one end, and an eyelet terminal on the other end.
Attach the eyelet terminal to body ground, near the relay, using a screw. Connect the other end to the relay terminal #86. There are 2 orange wires going to the original blower resistor/relay. Cut both of them close to the electrical connector. Using one of the 18” wires, solder it to the larger orange wire and connect it to relay terminal #30. Using another 18” wire, solder it to the smaller orange wire and connect it to relay terminal #85. Using the last 18” wire, connect it to relay terminal #87. At the blower motor there is a purple wire, don’t cut the wire, strip a section long enough to solder the wire from relay terminal #87.

Neatly tie up the wires so they don’t interfere with anything, and you’re done.

Any questions, just ask.
Old Master, is there any way to reactivate the pics for this helpful mod?...I'm unable to see them. Thanks again for sharing your wisdom.

Very old thread.
Hi,
I'm new to this forum and saw a post about what I'm working on, a 99 Astro with a blower motor problem where the high speed doesn't work and there's a burnt large power wire going to the resister
12 volts on the large wire to the resister relay
12 volts to the small orange wire
I saw that someone here posted a work around where they were adding a relay to bypass the resister...But that doesn't make sense to me how it is wired. If you disable the resister, then you only have the high setting and none of the others.
If I'm not missing something, wouldn't it be better to keep all the wires going to the resister relay except the large power wire and use it as a signal wire for the bigger relay and then use the red wire from the battery that was cut to the relay...
That way you could keep all the speeds and be able to handle the larger load of the fan motor when it is on high.
Please correct me if I am wrong, as I am looking for an alternative, but like I said I want the other speeds to work too...

Never mind, I wrote this late at night and realized what I want to do in this case won't work.:banghead: Any other ideas using a relay though would be appreciated.