Heater fan switch? Or Relay problem?

57chevyragtop · 02-11-2008, 06:20 PM

It's been awhile so I am posting this as new but with new info. Cold AM below 20 deg. fan won't come on any setting. Start turning it back an forth several times and it comes on in high mode...I leave it there get to my destination, leave switch in high positiong and turn car off. four hrs pass I start car and fan is on high just fine....car gets warmed up and I turn it down to any lower setting and fan shuts off...cant get it to come back on at all. Get to destination put switch on high (doesn't come on) turn car off. 1 hr later I start the car the fan comes on in high.....I go home and remain puzzled, any ideas on this are welcome. I am thinking relay or switch, but neither really makes sense to me....

dh271 · 02-13-2008, 09:41 PM

Here`s what my blower motor does. Most of the time it works fine except about once or twice a week. Turn the fan on, nothing happens. I`ve taken the access panel off under the glove compartment and slightly tapped the blower motor with my hand and then it comes on. Had a dealership tell me originally it was the heater control head ($443) and the the blower motor resistor ($233) to install them. I left (never to go back again) and found out it works fine after I bump it. Going to buy another blower motor on Ebay or a salvage, might spend $50 at the most, dealer wants $252 for the blower motor. I was told it might be just a bad contact point in the motor itself.

Don`t know if this will help, but might give it a try.

57chevyragtop · 02-14-2008, 05:20 AM

Right, I don't have much confidence in my dealer as well, sorry thing to say I guess but then they don't think they are the problem.
I am going to wait for warmer weather to get at this, way too cold for me, seems to be stuck on high for now. Though it does just quit at times. Probably built by Delphi which has always had quality issues with switches. I did a search and found other posts on this and seems to be popular source of frustration. Hey isn't GM in a bit of trouble?

57chevyragtop · 02-15-2008, 05:45 PM

Got a few questions if any would like to answer up please do so...First the fan quit working at all today so I sropped and talked to a couple of mechs that have worked on this type thing before and this is what they told me. If the fan works on high only it means the resistor relay is bad....if it does not work at all it is probably the electrical component attached to the ignition switch that has failed....does this sound right to you?? So if any of you know and can explain how to access underdash areas (how to take the covers off for one) and two...how to remove the ignition switch...going to library to see if a repair manual has any of this info but I have my doubts so I could use a little help on this.

brcidd · 02-15-2008, 06:15 PM

what year is your Impala? I can help you figure it out...I have seen several like this...

57chevyragtop · 02-15-2008, 10:14 PM

2002 base model, non dual climate control, ign in dash...under dash covers seem to have a plastic release but don't want to break them in the cold weather trying to get them out of the way. Library closed till Sat. AM. pretty sure all they have is wire diagram and not part explosion dia. As I understand it the lock cylinder and electric switching module are separable and the latter is the replacement piece that is defective. but I will circuit test w/volt meter first if possible.

j cAT · 02-15-2008, 11:14 PM

Quote:

Originally Posted by 57chevyragtop

2002 base model, non dual climate control, ign in dash...under dash covers seem to have a plastic release but don't want to break them in the cold weather trying to get them out of the way. Library closed till Sat. AM. pretty sure all they have is wire diagram and not part explosion dia. As I understand it the lock cylinder and electric switching module are separable and the latter is the replacement piece that is defective. but I will circuit test w/volt meter first if possible.

if you hit blower motor and it starts to run it is the brushes that are worn.... if you are going to keep car get new motor and before buying get meter and if voltage is at motor and connector to motor is clean and secure motor has worn brushes just like starter or fuel pump....sometimes you can't get it to work and a hit gets it to go......

57chevyragtop · 02-16-2008, 12:10 PM

Yeah, I get that...problem is I can't get the insullator panal to come off and don't want to break it. 2 squease clips won't release and I haven't quite got that figured out. (how they work) No instruction on that in the books I picked up....

j cAT · 02-16-2008, 02:51 PM

Quote:

Originally Posted by 57chevyragtop

Yeah, I get that...problem is I can't get the insullator panal to come off and don't want to break it. 2 squease clips won't release and I haven't quite got that figured out. (how they work) No instruction on that in the books I picked up....

is this the panel for access to motor...?

dh271 · 02-16-2008, 04:27 PM

Quote:

Originally Posted by 57chevyragtop

Yeah, I get that...problem is I can't get the insullator panal to come off and don't want to break it. 2 squease clips won't release and I haven't quite got that figured out. (how they work) No instruction on that in the books I picked up....

Should be able to push on the clips and and work the panel free. My son-in-law did it in a couple of seconds (didn`t break the clips either). There is a tool for those clips also at the auto parts stores.

Here`s a neat page on accessing the dash:
http://impalahq.naioa.com/HowTo/Dash.html

Kemi · 02-16-2008, 11:32 PM

Quote:

Originally Posted by 57chevyragtop

Got a few questions if any would like to answer up please do so...First the fan quit working at all today so I sropped and talked to a couple of mechs that have worked on this type thing before and this is what they told me. If the fan works on high only it means the resistor relay is bad....if it does not work at all it is probably the electrical component attached to the ignition switch that has failed....does this sound right to you?? So if any of you know and can explain how to access underdash areas (how to take the covers off for one) and two...how to remove the ignition switch...going to library to see if a repair manual has any of this info but I have my doubts so I could use a little help on this.

57chevy,

I'd be almost certain that your blower motor resistor is bad. Why? Because your fan did work on high, but not on other speeds. The resistor simply limits the amperage that can go to the blower thus decreasing the actual speed. On high, current does not flow through the resistor, rather straight to the fan. However, many resistors have a relay built into the unit so it could cause outright failure. Do you have access to wiring diagrams? Let me know if I can help.

57chevyragtop · 02-17-2008, 09:17 AM

In answer to the two questions posted J cat: yes this cover needs to be removed for access to the motor and resistor...Kemi: no, wire diagrams I have do not include this system, only instument panel...dh 271: thanks for the link at least tells me I am on the right track pushing on the clips. I'll repost shortly after I try again...Thanks all"

j cAT · 02-17-2008, 11:37 AM

[quote=Kemi]57chevy,

I'd be almost certain that your blower motor resistor is bad. Why? Because your fan did work on high, but not on other speeds. quote]

the original first post stated that the blower did not work at any speed I have troubleshot many of these and its usually the motor brushes worn or corroded connectors......... ...

57chevyragtop · 02-17-2008, 01:42 PM

Well I did get a chance to try again got one of the clips to release but not the other...forward of the inner clip is a push pin type retainer which as I understand takes a special tool (door panel puller). Why the other clip won't come loose is somewhat a puzzle...I'll try again tomorrow, fan is working on high sometimes and sometimes not...so it may be the resistor or corroded connector, just need to gain access first to test out...Thanks all for the input here....

j cAT · 02-17-2008, 04:07 PM

Quote:

Originally Posted by 57chevyragtop

Well I did get a chance to try again got one of the clips to release but not the other...forward of the inner clip is a push pin type retainer which as I understand takes a special tool (door panel puller). Why the other clip won't come loose is somewhat a puzzle...I'll try again tomorrow, fan is working on high sometimes and sometimes not...so it may be the resistor or corroded connector, just need to gain access first to test out...Thanks all for the input here....

to get the panel to release use dish soap mixed with water in a spray bottle this will safely lube joints to ease removal.......

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