climate control issue

[maxprime]

Hello everyone,
My 2001 with auto climate control is acting up. I searched the forums and didn't see anything. The control panel is powered on and everything works including all fan speeds without the key in the ignition. I did put a new resistor "3pin" in and it still is constantly powered. The only way I can get it to go off is by pulling the heater relay under the hood. I put a different relay in there and the problem still exists.
Anyone have an idea?

[Y33TREKker]

Does anything else work with the key not in the ignition switch? Does the power to the HVAC control panel change condition if you jiggle the key in the ignition switch or move it to different positions then back again?

One possibility is that your ignition switch is providing ground to the Automatic Heater-A/C Control module when it shouldn't be.

What happens if you pull the CB-6 10 amp Dome Light fuse in the dash fuse box?

That is the battery supply power for the Automatic Heater-A/C Control module.

If removing power from that lead-in to the control module turns off the automatic climate control system (which is a solid-state unit), it could be that the module has a short and needs to be replaced.

[maxprime]

Thanks for the help. So many things were going on that this was the first I got to look at it.

I tired what you asked and this are the results.

"Does anything else work with the key not in the ignition switch?" No. Everything is normal other than the hvac controls are live. jiggling the keys have no effect either.

"What happens if you pull the CB-6 10 amp Dome Light fuse in the dash fuse box?" The door buzzer and dome light go off. But, the hvac controls are still live.

Is there another relay between the rt fender power block and the control module that could be bad and powering it? If I pull the relay on the power block. It shuts havc controls off.

I checked the fuse box behind the battery and tested the relay connectors and found 2 are constant power on relay eb 25 and the center one is powered on eb 27 without the key on. I checked them against my 99 vehicross and only one is powered on eb-25 and none are powered on eb-27 with the key off. I made a diagram to show which are hot with the key off by marking them in "red".

[Y33TREKker]

Is there another relay between the rt fender power block and the control module that could be bad and powering it? If I pull the relay on the power block. It shuts havc controls off.

I checked the fuse box behind the battery and tested the relay connectors and found 2 are constant power on relay eb 25 and the center one is powered on eb 27 without the key on. I checked them against my 99 vehicross and only one is powered on eb-25 and none are powered on eb-27 with the key off. I made a diagram to show which are hot with the key off by marking them in "red".

Did you check with a voltmeter that the EB-27 (Starter Cut) relay showed proper continuities when you had it removed?

It should show continuity between pins 2 & 4 (the internal coil), and continuity between pins 1 & 5 when pins 2 & 4 (Normally Open switch) are energized with battery 12 volts. If continuity between pins 1 & 5 is present at all times, the relay is stuck or shorted (which would be keeping the Heater A/C relay energized at all times and applying power to your Auto A/C controls).

[maxprime]

Is there another relay between the rt fender power block and the control module that could be bad and powering it? If I pull the relay on the power block. It shuts havc controls off.

I checked the fuse box behind the battery and tested the relay connectors and found 2 are constant power on relay eb 25 and the center one is powered on eb 27 without the key on. I checked them against my 99 vehicross and only one is powered on eb-25 and none are powered on eb-27 with the key off. I made a diagram to show which are hot with the key off by marking them in "red".

Did you check with a voltmeter that the EB-27 (Starter Cut) relay showed proper continuities when you had it removed?

It should show continuity between pins 2 & 4 (the internal coil), and continuity between pins 1 & 5 when pins 2 & 4 (Normally Open switch) are energized with battery 12 volts. If continuity between pins 1 & 5 is present at all times, the relay is stuck or shorted (which would be keeping the Heater A/C relay energized at all times and applying power to your Auto A/C controls).

I did not. But, I will tomorrow. I hope that is it. thanks again.

[maxprime]

ok, This climate control issue is still unsolved. I've checked all the relays and and can't find any shorts in the wiring. I even changed the ignition switch and wiring to see if that would solve it and it didn't.
I'm now wondering if the climate control unit is the problem? Anyone know if the auto climate control out of a trooper is the same. From pictures on ebay it looks the same other than the front bezel is different. But , I noticed that that can be removed and I guessing put the one frome the vehicross on to make it work.
Anyone with an ideas it would be a great help.

Thanks in Advance.

[89Vette]

I would expect SUPPLY voltage to drop when the key is off. I would not expect the A/C control to drop voltage itself. The two other posters who've tried to help obviously believe the same...in providing suggestions where to look. The mere presence of a relay on that circuit implies [high amperage] voltage is supplied to the heater/controls when the car is turned on. That's why relays are used...to transfer the load "around" the ignition circuit.

Check other components on that circuit to see if they are still "live". How long has it been that way? Any chance it's been rewired incorrectly?

Did you try swapping relays (same ratings) to see what happened?

[Nikad92397]

Run another switched wire to power it..

[maxprime]

I would expect SUPPLY voltage to drop when the key is off. I would not expect the A/C control to drop voltage itself. The two other posters who've tried to help obviously believe the same...in providing suggestions where to look. The mere presence of a relay on that circuit implies [high amperage] voltage is supplied to the heater/controls when the car is turned on. That's why relays are used...to transfer the load "around" the ignition circuit.

Check other components on that circuit to see if they are still "live". How long has it been that way? Any chance it's been rewired incorrectly?

Did you try swapping relays (same ratings) to see what happened?

I have checked the relays in the fuse block under the hood and they are working properly and I also even replaced them with new ones and no difference. I also installed a new ignition switch harness in the column, same issue. The wiring hasn't been touched. So, I know it is not wired wrong.
Is there any other relays that could be stuck and causing this and if so. Does anyone know where they could be located? I already have 90% of the dash removed.

[Y33TREKker]

I have checked the relays in the fuse block under the hood and they are working properly and I also even replaced them with new ones and no difference. I also installed a new ignition switch harness in the column, same issue. The wiring hasn't been touched. So, I know it is not wired wrong.
Is there any other relays that could be stuck and causing this and if so. Does anyone know where they could be located? I already have 90% of the dash removed.

Since you have better access to the components in the dash at the moment, checking the wiring to the Automatic Heater A/C Control Unit would likely be the best indicator at this point.

Find out which wires have constant voltage being supplied then we can narrow it down between which wires/inputs SHOULD actually have voltage being supplied with the ignition switch off and which wires/inputs are possibly getting a supply of voltage at the moment that SHOULD NOT.

If we know that and it's determined that there is voltage currently where there shouldn't be, maybe we can start tracing backwards from there and determine the source of the problem.

[maxprime]

As for my continuing problem. I believe I narrowed it down to a short. On the heater relay socket I have 3 prongs that are charged. Using a test light I have 2 prongs lighting up bright and 1 dimmer . If I remove the stop lamp fuse it lowers the voltage on the dimmer one. But it is not out. I unplugged the brake switch and it had no effect. Checked the brake lights and they are working normal. Hope the weather holds out so I can get to the bottom of this.