96 Grand Am - No Air

Hello All,

I just got a 96 Grand Am for second vehicle, but it won't blow any air (hot or cold), I checked fuses they all look good. I'm thinking possibly blower motor, but wanted to get some feedback before I start plugging away. Any Thoughts?

First turn blower on, and tap motor housing with a hammer or handle of screwdriver....if it runs, replace the motor.....

Second, remove harness from blower motor and check for burnt marks in connectors(harness and motor) or for possible melting(caused by bad connection(resistance) which could cause melting.....

If ok, attach a test light to the disconnected harness connector.....key on, turn seclector to vent, and rotate blower speeds form low to high.....light should get progressively brighter....if it does, bad motor.....if it doesn't light at all, check fuses....if fuses are ok, then a bad resistor block....

Okay I hammered the blower motor and no response, and I put my tester in the wire harness and no light up....so we are going with resistor, but I'm looking through my manual and I can't seem to find how to replace it. Where is the resistor at? Another question when I turn the heat and air controls there's a quick sound like it's trying to turn on, but then nothing comes out, is that more or likely the resistor or could it be something else?

There is no resistor at max setting.
If at max it do not work, then you can automatically start to look for something else.

12V hot in run -> HTR-AC 25A fuse -> brown wire -> mode switch. All position but off go to the blower switch -> white wire -> blower switch.

Blower switch:
1-> yellow -> resistor pack D
2-> tan -> resistor pack C
3-> light blue -> resistor pack B
4-> brown -> blower relay coil

resistor pack A -> dark blue wire -> blower relay NC

12V hot in all time -> HVAC Blo Mot 30A fuse -> orange wire -> blower relay NO contact

blower relay common contact -> purple wire -> blower

location, as specified in the doc I have:
blower resistor: right rear of engine compartment.
blower relay: right rear of engine compartment.
25A fuse: fuse box
30A fuse: engine comartment fusebox.

What I would do to test:
disconnect harness at blower motor, with a test light check if it turn on. (Purple and black wire, black is ground, so you could be able to use the body if you can't access it)
If the test light turn on, there is an high chance that it's the blower motor. I would then check the resistance with an ohms meter, should be only a few ohms. if the reading is high, the motor is shot. if low, I'ld personally just try to feed 12V to it (warning: it might want 20A!).

From what you described, I can only think of a 25A fuse blown or the motor or multiple failure, which sound unlikelly. If the 25A fuse is blown it mean a short, so damaged wiring/resistor pack or motor or wiring modification.

Thanks, that fixed the first problem. Believe it or not (as silly as this sounds) there wasn't a blown fuse there was no fuse in the HTR/AC slot... Anyway, now to the real issue. There is no warm air coming through the vent so trying to figure out if this is simply a thermostat or if it's the heater core? I've heard that if heater core goes out that it leaks is that true?

missing fuse... go figure... lol :D If that fuse is missing, I would try to figure out why it's missing. A common cause is a blow lighter fuse, no proper fuse on hand, steal one that is not needed. The lighter I think it need a 15A fuse, might want to check to be sure that it's the right one that is there and not your missing 25A fuse, which could be a fire hazard.

Now, no heat could be a faulty actuator or broken bent door.
I do not have the reference on hand for it, but someone recently had that issue.

Basically, there is a door inside the unit that blend the air from the heater core and "bypass". That door can break, or the motor that actuate it can die.