Yep. I have an 86 LG4 Trans Am 5-Speed and tonight after getting home i turn off the car and my AC keeps blowing in Hi fan speed. I check under the hood and I feel a bunch of air by the blower motor.

I turn the engine back on and I only have Hi fan speed on my AC. Switching to med or low doesn't change anything. It blows Hi.

Its too dark right now to see anything but any tips or advice appreciated. THANK YOU.

Carlos

 

Disconnect the battery for now or pull the high speed relay by the blower housing.

 

History would help.

How long have you had this car? How long has it done this? Did it just start? Been doing any kind of work on it? ... We can all go 15 rounds of maybe it's this maybe it's that in a vacuum but that's not likely to be much help fixing it.

As said, unhook the batt so that it doesn't run down tonight, and tackle it in the morning with light and a fresh mind. Don't trust to the relay being the culprit.

 

That's what I did i disconnected the battery for the night. I've had the car a month or so. No work done because all's been fine up to now. The wiring between the blower motor and from the resistor sure doesn't look OEM but ill check it out and post pics in the morning.

Thanks again guys.

 

This morning I got a better look and I removed the hi speed relay and a bunch of black water dripped out and there are signs of overheating.



The connector looks pretty crappy as well


The wiring (if it's factory or not i don't know) looks ok. The resistor and wiring from the resistor also looks fine.

I noticed that if I "wiggle" the connection between the hi speed relay and connector when the issue is present, it goes away. Perhaps a bad connection there caused by the water intrusion? I found the correct hi speed relay online and its on the way but I can't find the connector section at the moment. I'll keep looking.

 

I’m thinking the relay got stuck

http://www.austinthirdgen.org/mkport...C60_manual.jpg

 

Because of all the water that got in perhaps? Thanks for the diagram by the way.

 

A engine cooling fan relay would be more weatherproof efi connection or tpi parts has them relays have the schematic on top as well.

 

That doesn't look right.

The blower high-speed relay should have 5 contacts, not 4.

Neither the connector nor the relay belong there. They're both "factory", just, not for that application.

Also, the wires should be a fat purple, a fat red, a smaller orange, a pink w/black stripe, and a green w/ white stripe. I see most of those colors of wires in there except that somebody has butchered them.

Looks like some sodomy has occurred there, somewhat recently, by someone who put forth a valiant effort but didn't know what they were doing.

I'd suggest a relay and connector about like this. https://www.americanautowire.com/shop/relay-4826 It's waterproof, MUCH better than the original in your car; in fact later cars used one like this instead.

Automotive relays commonly have an inscrutable terminal designation, usually numbers; hook the green/white to 85 or 86 and the pink/black to the other of those, the purple to 30, the fat red to 87 (be careful: it has hard battery on it), and the orange to 87A. Use electronic (NOT plumbing) solder after crimping those connectors on (they don't have to be near as carefully crimped if you do that) with some rosin flux. You can get all that stuff at MicroCenter or places like that.

 

If you fix the wiring and still have the issue, it could be your ignition switch. This is the switch that is under the dash and mounted on top of the steering column (NOT the key ignition). I have had 2 or 3 of these go bad on different GM vehicles and they allow ignition current to continue flowing even when you shut off the ignition. Each time I have noticed the blower fan will continue running after ignition is turned off. They are cheap and pretty easy to replace.

 

Thank you for all the advice. I'll get to work on some reading on repairing the wiring.

 

Will check this out. Thanks.

 

86 Firebird Blower relay only needs 4-contacts........ 5th contact shown as "not used". These diagrams are for the 1986 "manual" ( not digital dash ) Firebird.





Obviously; Since the relay had water in it,... start by replacing that thing !

 

I knew you had the right schematic

 

I have my moments !!

 

You're right, I'm sorry. The coil wire colors I quoted were for the cooling fan relay, not the HVAC one. Brain cramp.

 

Quick update: I ordered a relay/plug from americanautowire. It'll take a few days but I received the relay I had ordered originally from amazon. I placed it and the hi speed works again manually and so far no instances of the blower coming on with the car off.

I'll be keeping an eye on it until I get the parts in ordered.

Thanks again for all the help.