1996 Dodge Grand Caravan LE AC/Heater Blower, Relay and Resistor Block Problems 101

[Dchall_San_Antonio]

When I wrote that before I had not read the original posts that carefully. Turns out the diagnosis was for either the relay or the motor. It was the motor.

I damaged the plastic squirrel cage at the rim trying to get it off the shaft. There was a crack but nothing separated. I filled the crack with Gorilla Glue and put it back together. So far so good.

One more thing. The wires on the new motor would not go through the inner grommet without hitting the squirrel cage. The wires come off the replacement motor differently from those on the OEM part. So instead of running it through the grommet, I ran them down the side of the motor using a tie wrap to guide/hold the wires down the side of the motor.

[HeadlessHorseman1]

Originally Posted by Dchall_San_Antonio

Ahhhhh! Life's classic issues, and their solutions, are truly a thing of beauty to behold. My highest praise goes to you, Headlesshorseman, for your efforts in bringing a solution to so many of us. And certainly thanks to the other contributors. With all the models and versions, it would be very expensive for one person to learn all there is to know about this topic. You gotta love the Internet.
...
I already went through this on the 96. Back then it was my wife's car and it had to be fixed immediately, so I spent the $400 to replace everything all at once. Since they replaced everything, I can't know for sure what was wrong. But now it is my car and I can do it myself (thanks to this classic post). I'll probably change the resistor block next weekend and go from there.

I have long felt that the best thing to do when encountering ANY problem with the (1) relay, (2) resistor and/or (3) blower motor was to replace everything all at once. I am on my 2nd relay, second resistor and my 3rd blower motor since I bought my GC/LE in '96. In the beginning, I would replace these items 1 or maybe 2 at a time only to have the other(s) crap out soon after (within a year, usually).

When I started this thread almost 3 years ago, I decided to replace all 3 components at once (relay, resistor and blower motor)... and I have not had a problem since then. Replacing all 3 at once may seem excessive, but in the long run, I spend less time fixing things and worrying about which of these doodads will crap out next.

P.S. I just turned over 251,000 on the odometer of my 1996 GC/LE with the 3.8 liter motor... the best motor I have EVER owned, at that includes several new Toyotas, a Datsun and a Nissan. On my GC/LE, I have replaced 1 water pump, 1 alternator and 1 idler pulley... that's it. (The transmission however, well, let's not go there... I am on my 3rd.)

[HeadlessHorseman1]

Originally Posted by Gervais8

My fan was only working on high. I replaced the resistor and it worked on all speeds for a week, maybe. Now there's no fan at all. Also, the green a/c button will stay on even if the fan is off. If I have the fan turned off or even if the fan is turned on you can feel cool air coming through the vents but it's not blowing. The recirculate button is off but if you push it on you get no air at all from the front vents. The rear air works fine. I looked up underneath the glove box and felt around. The areas underneath were really cold from the a/c I assume. Can someone help with suggestions?

Please see my above post (opinion) about replacing all 3 items at the same time, all at once... relay, resistor and motor.

[HeadlessHorseman1]

Originally Posted by 2001es

I have a problem with my 2001 GC es.. The A/C blower will run when the ignition switch to ON and the Power botton is OFF anf it runs on high speed...If you push the recirculating botton the speed of the fan changes to high and low speed....Ive checked the relay and and the resistor and its ok they are in good shaped...
BTW, i removed the two connectors behind the climate control and the fan still running.. The fan speed is nt working as i have said it is running on one speed....no low,med,high...
Anyway \, anyone could relate the problem i have will highly appreciated...
Thank you..

Please see my above post (opinion) about replacing all 3 items at the same time, all at once.

[HeadlessHorseman1]

Originally Posted by fastclock

I'm done replacing the blower motor resistor, and now the blower has all the speed settings Got help from my father in law

So, after setting the AC pipe aside, it is still a struggle to pull out the resistor through the space in between the strut tower and the wiper block, but it can be done. I took out the wiring + resistor, and then pull out the wiring from the old resistor, put in the wiring on the new resistor ($13.60 from the dealer).

I clip the left bottom part of the board support of the resistor, this helps a lot in inserting the new set back on the firewall.

And finally, the rusted resistor:
http://www.flickr.com/photos/12959620@N08/1346032847/

Yep, your pic is pretty much what I found when I finally got my resistor block out of the firewall. I did not have all of the problems you encountered but I was not surprised to read about them. Resistor blocks in mid-to-late 90's Caravans have always been a bee-otch to remove and replace. So, we can add your knuckle-skinning story to the long list of other blood-letting sagas the engineers at Chrysler has cooked up for us.

Congratulations on your success!

[fastclock]

Originally Posted by HeadlessHorseman1

Yep, your pic is pretty much what I found when I finally got my resistor block out of the firewall. I did not have all of the problems you encountered but I was not surprised to read about them. Resistor blocks in mid-to-late 90's Caravans have always been a bee-otch to remove and replace. So, we can add your knuckle-skinning story to the long list of other blood-letting sagas the engineers at Chrysler has cooked up for us.

Congratulations on your success!

The fan died a month ago after making some growling sounds and stopping after two-hours drive. So, I replaced the relay, and the fan still wouldn't work. After ordering a used blower motor from car-part.com (not sure how long will keep the van, $10 part + $13 shipping), I replace the whole fan+cage without a problem. I'm not sure I can replace just the motor, so took this path.

Thanks for the info again. Now the fan is blowing just fine.

[HeadlessHorseman1]

Originally Posted by fastclock

The fan died a month ago after making some growling sounds and stopping after two-hours drive. So, I replaced the relay, and the fan still wouldn't work. After ordering a used blower motor from car-part.com (not sure how long will keep the van, $10 part + $13 shipping), I replace the whole fan+cage without a problem. I'm not sure I can replace just the motor, so took this path.

Thanks for the info again. Now the fan is blowing just fine.

You're welcome and, actually, you *can* replace just the motor, but you have to remove the squirrel cage from the old one and press it onto the motor shaft of the new motor (the procedure is in my original page 1 post). At any rate, I'm glad it all worked out for you... congrats!

[Krazy Jeff]

First of all a big thanks to HeadlessHorseman for providing us a great tutorial.

My situation fits Question #3 - Does your AC/Heater Blower Motor seem to "growl," run slow or stop altogether AFTER running for awhile, though sometimes it seems by turning it off and waiting awhile the problem resolves itself, but only temporarily?

Here are my symptoms. I turn on car, turn on ac/heater, it's blowing out of the vents, then I turn off car, turn on car, and then the ac/heater sometimes just doesn't turn on. Or when driving, it turns off, and it won't turn on again, until probably I turn off the car and let it sit there for a few hours or so.

Here is what I have done so far to troubleshoot it.

1. I replaced the Blower Motor Relay. (but the symptoms still persist).
2. I then disconnected the connector where the blower motor gets its power from (removed glove compartment) I then connected a voltage meter on the connector where the blower gets it's power from. I notice that it's getting 12 volts of power. I then reconnect the blower. Go through the procedures of getting the blower to fail (as explained above in the symptoms). Once the blower fails, I disconnect the power adapter and test it again with the voltmeter and now it's getting no voltage. So the conclusion is that the motor doesn't run, because it's not getting anymore voltage. (so it can't be a bad motor blower) Could I be right?
3. I then go to the Fuse & Relay Center and barely tap the blower relay and it turns on. I then proceed in turning on and off the car and then see when the motor blower fails. Once it does, I just tap the top part of the fuse & relay center and voila, it turns on.

This is where I am currently stuck at. Why is it that I barely tap on the cover of the Fuse & Relay Center (underneath the hood) and it seems to reset the relay box? Please help?

Also, can someone explain what is the main purpose of the blower relay? Could there be a way for me to bypass the blower relay so the blower motor is constantly getting 12 volts and it only turns on by turning on the switch on the AC/Heater Controller?

I haven't tried testing the resistor, because all levels of the fan works Low/Mid/High. So this is why I haven't bothered to see if this could be the problem.

[HeadlessHorseman1]

Originally Posted by Krazy Jeff

First of all a big thanks to HeadlessHorseman for providing us a great tutorial.

My situation fits Question #3 - Does your AC/Heater Blower Motor seem to "growl," run slow or stop altogether AFTER running for awhile, though sometimes it seems by turning it off and waiting awhile the problem resolves itself, but only temporarily?

Here are my symptoms. I turn on car, turn on ac/heater, it's blowing out of the vents, then I turn off car, turn on car, and then the ac/heater sometimes just doesn't turn on. Or when driving, it turns off, and it won't turn on again, until probably I turn off the car and let it sit there for a few hours or so.

Here is what I have done so far to troubleshoot it.

1. I replaced the Blower Motor Relay. (but the symptoms still persist).
2. I then disconnected the connector where the blower motor gets its power from (removed glove compartment) I then connected a voltage meter on the connector where the blower gets it's power from. I notice that it's getting 12 volts of power. I then reconnect the blower. Go through the procedures of getting the blower to fail (as explained above in the symptoms). Once the blower fails, I disconnect the power adapter and test it again with the voltmeter and now it's getting no voltage. So the conclusion is that the motor doesn't run, because it's not getting anymore voltage. (so it can't be a bad motor blower) Could I be right?
3. I then go to the Fuse & Relay Center and barely tap the blower relay and it turns on. I then proceed in turning on and off the car and then see when the motor blower fails. Once it does, I just tap the top part of the fuse & relay center and voila, it turns on.

This is where I am currently stuck at. Why is it that I barely tap on the cover of the Fuse & Relay Center (underneath the hood) and it seems to reset the relay box? Please help?

Also, can someone explain what is the main purpose of the blower relay? Could there be a way for me to bypass the blower relay so the blower motor is constantly getting 12 volts and it only turns on by turning on the switch on the AC/Heater Controller?

I haven't tried testing the resistor, because all levels of the fan works Low/Mid/High. So this is why I haven't bothered to see if this could be the problem.

Obviously, your 40amp fuse is good and since you replaced the Relay, we should assume it is also good. When the Blower Motor blows, it works at all speeds, so it seems safe to assume that the Resistor Block is OK too. You did not mention whether or not your Blower Motor is "growling"... if it is "growling" (running very slow), the Blower Motor would probably need to be replaced. "Tapping" the Fuse & Relay Center cover seems to cause the blower to work, so I would suspect that 1 or more of the 4 or 5 Relay prongs have a bad socket connection or possibly there is a wiring issue. It is possible that you purchased a defective Relay, but I doubt it. This is where I would start...

1. disconnect the negative battery cable,

2. remove the relay,

3. get some canned air (the kind you use to blow out computer keyboards) and blow out the sockets used to plug in the relay,

4. get some dielectric grease and carefully coat each metal prong of the relay using a Q-tip,

5. reinsert the relay,

6. reconnect the negative battery cable,

7. test,

8. come back here and let us know how you made out.

BTW, the purpose of the Relay is to handle the high-amp load of the Blower Motor circuit... relays do a better job of this than a simple switch (which would probably burn out in a short period of time without a Relay between the switch and the motor).

Good luck!

P.S. Thank you for your kind words about the effectiveness of this thread... this has been and continues to be a collaborative effort that has grown over the past three years with several key people contributing comments and pictures and others who come back after they've fixed the problem(s) to provide helpful and insightful notes in this thread. Thanks to everyone who has participated, this is the most viewed, most posted thread in this forum. There is a solution to your Caravan's problem and when we find it, if you return to post your comments, you too will become a contributor to this thread. Once again... thanks to All!

[Krazy Jeff]

Thanks for the quick reply. I will definitely try the canned air and dielectric grease. (Question? When you buy new spark plugs, do they normally give you a dielectric grease in a small clear bag? If yes, I got a whole bunch.. lol)

Define "growl"? When I put it on low, it blows the air low, at half way it blows the air moderately, and when its on high it really pushed the air. I wish there was a better way to gauge this to make sure it is blowing at its optimum speed or power.

Wish me luck, I'll be testing this tomorrow or by Monday.

[HeadlessHorseman1]

Originally Posted by Krazy Jeff

Thanks for the quick reply. I will definitely try the canned air and dielectric grease. (Question? When you buy new spark plugs, do they normally give you a dielectric grease in a small clear bag? If yes, I got a whole bunch.. lol)

Define "growl"? When I put it on low, it blows the air low, at half way it blows the air moderately, and when its on high it really pushed the air. I wish there was a better way to gauge this to make sure it is blowing at its optimum speed or power.

Wish me luck, I'll be testing this tomorrow or by Monday.

I have never received small clear bags of dielectric grease with plugs I've bought in the past. I wouldn't think dielectric grease would hold up well in the high heat. I have used copper-based anti-sieze "grease" on the threads of spark plugs to improve conductivity and make their eventual replacement easier.

I would not use the stuff that came with your plugs on the metal prongs of the Blower Motor Relay unless it specifically states on the bag that it IS dielectric grease... it might make things worse.

It sounds like your Blower Motor is OK... "growling" is what happens when the Blower Motor spins very slowly, slower and slower and may eventually stop spinning altogether... like the bearing is bad and siezes up. It also sounds like your Relay and Resistor Block is OK.

Please do come back and let everyone here know about your progress... Good Luck!

[paitchison]

I'm not really a DIY'er, as I have a valid Automotive Mechanic's Licence, although I haven't been in the trade for a little while.
I have spent approximately 9 hours trouble shooting my heater problem. I had it traced to the heater relay, but spent 8 of the 9 hours trying to locate that little black $%#*2+. That's even with a factory shop manual !!! I have the scrapes and cuts to prove it. I was all set to start installing a new wiring and relay, when I decided to Google "1996 Caravan heater" and found your site. To say the least I was relieved. I followed your instruction exactly and now have a perfectly fine heater system again. I have documented the procedure with 15 annotated digital pictures and would send them to you, if I could figure out how. Email me at paul_aitchison@hotmail.com, if you would like them.Thank you for taking the time to record your experience for the rest of us dumb slobs.
Paul Aitchison

[HeadlessHorseman1]

Originally Posted by paitchison

I'm not really a DIY'er, as I have a valid Automotive Mechanic's Licence, although I haven't been in the trade for a little while.
I have spent approximately 9 hours trouble shooting my heater problem. I had it traced to the heater relay, but spent 8 of the 9 hours trying to locate that little black $%#*2+. That's even with a factory shop manual !!! I have the scrapes and cuts to prove it. I was all set to start installing a new wiring and relay, when I decided to Google "1996 Caravan heater" and found your site. To say the least I was relieved. I followed your instruction exactly and now have a perfectly fine heater system again. I have documented the procedure with 15 annotated digital pictures and would send them to you, if I could figure out how. Email me at paul_aitchison@hotmail.com, if you would like them.Thank you for taking the time to record your experience for the rest of us dumb slobs.
Paul Aitchison

I would like to begin by saying you are not a dumb slob, Paul... hey man, I fixed my heater system for the first time three years ago and felt like I was out there on my own. That was the reason why I started this thread way back then... so guys wouldn't have to go through the same "pain and suffering."

Yes, I would like to get the pictures you took!... and thank YOU Paul for coming back to this web site to share your experiences... this thread just keeps getting better and better because guys like you help make it that way!

Congratulations on your success... it makes me personally very happy to know that there is more money in YOUR pocket and not in Chrysler's bank account... I wish you MANY years of problem free service.

[mux]

Originally Posted by HeadlessHorseman1

(The transmission however, well, let's not go there... I am on my 3rd.)

Are you sure the transmission was actually bad? I had some issues with the Dodge Caravan that I own but it turned out to be the shift selenoid and the wiring to the sensor on the transmission.

My van would not shift gears it was stuck in 2nd gear and after a lot of research and troubleshooting I was able to replace the shift selenoid and all was fine. The selenoid was not cheap but it was a whole lot cheaper and easier to fix than a transmission replacement.

Dodge Caravans have what they call limp home and the tranny will not change from 2nd gear.

Thanks for all the info on the heater resistors I will be replacing that soon.

[HeadlessHorseman1]

Originally Posted by mux

Are you sure the transmission was actually bad? I had some issues with the Dodge Caravan that I own but it turned out to be the shift selenoid and the wiring to the sensor on the transmission.

My van would not shift gears it was stuck in 2nd gear and after a lot of research and troubleshooting I was able to replace the shift selenoid and all was fine. The selenoid was not cheap but it was a whole lot cheaper and easier to fix than a transmission replacement.

Dodge Caravans have what they call limp home and the tranny will not change from 2nd gear.

Thanks for all the info on the heater resistors I will be replacing that soon.

Wellllll... there I was parked at a stop light, light turns green and I accelerate. Then... BANG! I lose all power and my transmission literally sounds like a large coffee can filled with nuts and bolts being rattled around.

It was U-G-L-Y. In addition, I blew a half-shaft. Not one of my better days.