97 GC - Blower comes on by itself -- with no key!!

PoBoy proclaimed:

If this is the auto setup on the GC, more likely to be the controller gone skyward. Would make more sense than the manual system managing to do this.

Yeah, although with the caution that the reason a shop would charge an arm and a leg is due to the sheer PITA factor.

If you have the auto temp control system, and ever see "Er" on the display note the numbers.

You can completely run the ATC system thru every control from the panel, but first pull any stored fault codes:

Press A/C and RECIRC and hold. Rotate control knob one click clockwise. This should light all indicators and segments on the display.

Then release the A/C and RECIRC button, which should show test 00 on the display.

Then push ONE OF either A/C or RECIRC which should show a little stick figure. Any number other than 00 at this point should be recorded. You really don't want to see a 25 or 29, $$$.

I do use the auto setup. I have never seen an Er but will step thru your diag procedure.

Would a fault not cause the check engine light to go on?

When you say the controller is cooked, do you mean the Blower Motor Power module or the Automatic Temperature Control (ATC) Module or something else?

thx, James

L> PoBoy proclaimed:

No the blower under the dash, definitely not the rad fan. When the thing turned on this morning , i was just standing there looking at it,

It hadnt run s> You're not talking about the auxiliary radiator fan, that's meant

PoBoy proclaimed:

No, the ATC has its own set of diags. You can also step the entire thing thru a full set of input and output checks including stepping the fan, blend door, etc. etc. thru all positions.

Hard to say, the ATC is what controls the blower, but I would *think* that with the key off, it would take the power module to make it come on with no ignition on.

PoBoy proclaimed:

Hopefully you still have the "Enter Diag Mode" where you press and hold the two buttons on the ATC, then click one time to display a 0 with the stick figure.

While running diags, you can go back to test select mode by turning the temp control one click in either direction which should get rid of the stick figure and any arrows.

From the diags mode, turn the temp knob until the desired test is displayed in the digits. Then press A/C or RECIRC to display the value or select an output test mode by pressing again until the display blinks. Normally you read an output first, then hit that button again to run the actuator test.

For number display:

No arrows= 0-99 Middle [panel] arrow = 100-199 Panel + Defrost arrow = 200-299.

Test:

1 blower control switch, A/D convertor. Display only 2 blower feedback display only 3 blower speed, can run an actuator test 4 blower high speed relay can run actuator test.

Yes the 2 button diag mode entry works, I did the first diag procedure and got 00 code, next i'll try the individual tests.

james

L> PoBoy proclaimed:

PoBoy proclaimed:

You might wish to cough up for the Factory Service Manual and Body Diagnostic Manual from

Much of the stuff presumes you have a scan tool, but the rest comes in handy even if just so you can perform some of the road tests before having a chat with your mechanic.

The factory service manual is easy to find, but did you get the 'Body Diagnostic Manual' from them too? I couldnt seem to pull it up.

thx, jt

L> PoBoy proclaimed:

PoBoy proclaimed:

Hmmm, it was there when I ordered it, but that was a few years ago, fairly cheap, and that may not be the name on the website, look for something only about 10 bucks if memory serves.

My mechanic just called, he says that the blower relay, which supposed to be under the dash isn't where it should be.

He suspects that it may have been put under the dash in some previous repair. I bought it in 2000 and this dealer is the only guy who has worked on it . The vehicle itself is in great shape but who's to say.

Could it be that the relay is > Thanks to all on tips about my (non)heated seat.

PoBoy did pass the time by typing:

Feel in the harness, working back from the resistor pack. About a 1" cube covered in tape. It's got a "squareish" feeling rather than the "roundish" loom.

IIRC it was close to the blower motor, possibly on the back side or above the ducting.

It's there, just damn hard to find.

Select Diagnostic Manuals and 1995 Diagnostic Manuals. Then in the results, go for the "next 10" until you get to document number 81-669-94021 and the price is $7 bucks.

Thanks, I ordered the service manual yesterday, i will get this one too.

jt

L>

PoBoy did pass the time by typing:

It has to be there or your blower wouldn't work at all.

Maybe the '97 GC has a blower relay but my '97 TJ doesn't. The +12 volts goes directly to the blower resistor pack.

Jerry

DougW wrote: