Heater is not working

[Lorrie]

Hi!

I am new to the forum and am hoping someone can help me with a heater/defroster fan issue I'm having in my 1989 Chevy Suburban (she is my baby and I've had her for 23 years).

The problem:
The fan in my rig has been working intermittently for a couple of years.
Sometimes when I tried to turn the fan on it wouldn't come on. After driving for 5 minutes or so, the fan would turn on and the heater/defroster would work just fine.
Other times, the fan would turn on immediately and would run for a while before deciding to stop working. Eventually it would start working again.

What I have tried:
After talking with a car guy I know I replaced the blower motor resistor. This did not fix the problem.
Since it would sometimes turn off after running for a while he thought the blower motor might be overheating. After replacing the blower motor the issue still is not fixed.
I decided that it was probably the fan switch. If the fan stopped working and I fiddled with the lever I could usually get it to turn back on.

So...I pulled the temperature control unit today and the old switch was fried. I put in a new switch and it still doesn't work!! Help!!!
I checked the fuse and it is not blown. The only other thing I can think of is that the old fan switch took out the connector (what the switch was plugged into).
Is there something else that could be causing the problem?

Thank you!
Lorrie

 

[AuroraGirl]

Hi!

I am new to the forum and am hoping someone can help me with a heater/defroster fan issue I'm having in my 1989 Chevy Suburban (she is my baby and I've had her for 23 years).

The problem:
The fan in my rig has been working intermittently for a couple of years.
Sometimes when I tried to turn the fan on it wouldn't come on. After driving for 5 minutes or so, the fan would turn on and the heater/defroster would work just fine.
Other times, the fan would turn on immediately and would run for a while before deciding to stop working. Eventually it would start working again.

What I have tried:
After talking with a car guy I know I replaced the blower motor resistor. This did not fix the problem.
Since it would sometimes turn off after running for a while he thought the blower motor might be overheating. After replacing the blower motor the issue still is not fixed.
I decided that it was probably the fan switch. If the fan stopped working and I fiddled with the lever I could usually get it to turn back on.

So...I pulled the temperature control unit today and the old switch was fried. I put in a new switch and it still doesn't work!! Help!!!
I checked the fuse and it is not blown. The only other thing I can think of is that the old fan switch took out the connector (what the switch was plugged into).
Is there something else that could be causing the problem?

Thank you!
Lorrie

is this truck AC?

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My truck is not ac, but I have noticed the fan sometimes doesnt work, and if I wiggle and play with the fan switch, it will kick on. If I have no luck, I will unplug it and shake it. being yours is on the panel, its worth playing with it to see if it helps and maybe replacing if you find its intermittently working

 

[Lorrie]

My a/c hasn't worked for 15+ years.

I have wiggled and played with the fan and it used to kick on, but not any more. I replaced switch (it was fried), but it still won't work. I don't know if it took something else out with it.

 

[Lorrie]

The first picture shows the new fan switch plugged into the connector.

The second picture shows the old switch that was fried. Is it possible that the bad fan switch took out the connector? What else could it be?

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[Snoots]

You need to get an ohmmeter and check the feed wire to the switch.

 

[Lorrie]

I am not very good with electrical. Where would I find the feed wire?

 

[dvdswan]

There are wiring diagrams in the reference library.

https://www.gmsquarebody.com/threads/1973-1991-wiring-manuals.14498/

They will tell you the color codes of each wire.

 

[Lorrie]

The problem has been discovered. After installing the new blower motor and finding out that it didn't fix the problem, my husband checked to make sure the blower motor wasn't faulty and one of the wires didn't get reattached after he checked it. He just reattached it and the fan is working. Yay!!

 

[AuroraGirl]

The problem has been discovered. After installing the new blower motor and finding out that it didn't fix the problem, my husband checked to make sure the blower motor wasn't faulty and one of the wires didn't get reattached after he checked it. He just reattached it and the fan is working. Yay!!

SUCCESS

if your ducts smell, nows a good time to get an ozone generator and run a short spurt or 2 to neutralize any odors. Thats not mandatory just potentially helpful if you have musty odor

 

[Dave M]

SUCCESS

if your ducts smell, nows a good time to get an ozone generator and run a short spurt or 2 to neutralize any odors. Thats not mandatory just potentially helpful if you have musty odor

Or this.

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[AuroraGirl]

Or this.

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I dont think that would be very effective on musty dead mice 40 year old hvac duct smells.

you're welcome to try

 

[Lorrie]

I actually don't have any musty smells coming from the ducts.

On to my next project - replace the cracked dash!