Hi there,
I am trying to fix the high speed of the heater blower fan. The low medium and high speeds are working, so the resistor is working. Just the full power is not working. I included a couple pics of the relays around the fan motor, any ideas where to look?

 

That relay would be the first place, thats what it for. Second place would be the blower switch. If neither of those is it, then onto the wiring.

 

Yep, that relay located close to the HVAC fan in the picture is the one.

 

Thanks for the responses. I tried probing the wires in the relay, 2 showed green lights, 2 nothing. None of them turned the high-speed fan on. I also tried swapping relays with what I think is a known good one, that still did not work.

 

Maybe check the fan switch, especially the orange wire

 

Thanks for the reply 84 1LE. I swapped out a known good switch, they both work the same. Does anybody know what relay number should be used for the high-speed relay? I have seen 3 different numbers, so I don't know which one is correct.

 

In the 2nd pic in your original post, observe the white connector right above the valve cover.

THAT'S your problem. I bet if you try to unplug it, you might find that it's melted to a crispy blob, and the actual "connector" parts, the metal, will show signs of having been red-hot.

I've posted this about a million times, here https://www.thirdgen.org/forums/elec...t-working.html for example. There's a buncha typical "look it up in the FSM" type stuff which of course is as useless as **** on a chicken, then about halfway down the REAL info starts to get posted.

 

Is that the light grey plug with the big red wire in it? That does not have a cooresponding plug to go with it. There are many wires the PO cut under the hood. Do you know where to get the power from?

 

For that, refer to 84's schematic, in post #2.

Observe C112, in the Big Red Wire numbered ... 2. That's the thing you found that isn't hooked up. Which, since it supplies battery to the high-speed relay to replace the stepped-down version for lower speeds that comes through the resistor assy, fits the criterion in my signature for why your high speed doesn't work. Note that this wire is 5mm cross-sectional area; that's about 10 ga, or very slightly smaller (between 10 & 11... we could call it about 10¼ gauge if we wanted to get picky). Note that the other end is a splice, S123, where it meets some other Big Red Wires, also with callout 2. Note that one of them is fed from Fusible Link B, color-coded "rust", which in turn is fed from "hot at all times". GM-speak code word for "battery". The FL is actually down at the starter, at the far end of the red batt cable; that's where it gets its battery from.

First thing to do is, look around for the other half of C112. Might be buried down in some PO wiring mess somewhere, who knows. You could also try tracing it the opposite way, by going to the starter, finding FL B, and tracking it up toward the half of C112 you DO have. Then GET RID OF C112, as described in the link I gave you, and replace it with something that won't let its own magic smoke out.

If that wire is just ... gone, like the evaporator core (what a TERRIFIC "improvement" THAT is!!!), I'd suggest you go to the store and get some #10 red wire and a "rust" FL, and just make up the thing that the PO "improved" the car by HACKING out of it, using rosin-core solder and heat-shrink tubing. Of course, you would do all this neatly and in a sanitary respectable and reputable manner, making sure that the new wire is well secured in the split-loom all down around there, and not hanging out in the open like a clothesline. And of course, blocking off the giant hole that the PO left when s/he made that phenomenal "improvement" of HACKING the evap core out, otherwise all the air that the blower blows will go that way instead of into the ducts in the dash.

A license should be required to own a pair of dykes, and an unbreakable oath should have to be sworn by a prospective licensee not to do what your car's PO did (sodomy); and there should be a Dyke Law, enforced by Dyke Police; and anybody that violates Dyke Law should be sentenced to 30 years of hard time in Federal Pound Me In The A$$ Prison. Including the PO that sodomized your car.

 

Also looks like your evap housing has the usual hole in it right above the exhaust manifold where the crappy material they used crumbled to dust from the heat, which needs to be fixed.

 

Wow now I am really confused. I found another red wire, snipped off on the driver's side. In pic 1, the wire with the yellow butt connector on it. I thought it might work if I connected it to the red wire in pic 2, that is the wire that had the grey connector on it, pic 3. Connecting the 2 red wires did nothing. I put a test light on both wires, and both are hot at all times. Green light on the test probe.

I don't know how to hook up power to the high-speed fan.


driver's side red wire, yellow connector

pass side wire, grey connector

grey connector

 

Suggest you stop and pay somebody. This is super basic stuff with complete documentation provided earlier and you're not getting it at all. Best to step away and let somebody else take over.

I shouldn't weld, and you shouldn't touch electrical. Both our cars will be better for it.

 

IT'S FIXED!
I traced the red wire from the high-speed relay, and found the roasted connector. I spliced in the red wire that has power, and the fan now works at high speed. And the other speeds still work too. All good.

 

Awesome! Sorry I underestimated you. (I still can't weld though)

 

Qwktrip, thanks for pointing me in the right area, I was backwards on which way the wire was going. I thought the red wire with the grey connector was coming FROM the high-speed relay, and I needed to connect a power wire to it. So I started at the relay, and traced the red wire from there. I found a black connector on top of the evap box that is pretty crispy. Looks like it should have had a red wire in it, but that socket is toast. So I cut the red wire from that connector, and spliced in the red power wire. Works like a charm. Now, on to the rest of the chopped-up mess. One circuit at a time, I guess.

 

Have you tried MIG welding?
I have not met anyone yet, that could not pick it up.

I primarily have TIG Welded...
But with Eye and Hand Injuries, I have had to fall back on MIG Welding.