AC Controller

[Chargered]

I recently installed a new push button AC controller in the dash of my 70 Charger. Everything seems to work good. The fan works when I push the AC, Max AC, Heater and Defrost, but when I push in the Off button to shut it down, the fan slows way down, but doesn't completely stop. It continues to creep at a very slow turn until I pull the off button back towards the rear of the car. It should shut the fan down completely when you push in the Off button, but it doesn't?

Anyone have any ideas on what the problem might be? Bad push button controller, wiring mixed up or something else?

Thanks for the help.

 

[ckessel]

Are you using an aftermarket a/c system?

 

[Chargered]

I'm using a Sanden AC compressor, but most everything else is the original equipement.

 

[Omni Source]

Good Morning

I believe that the fan always runs on a slow speed until you turn it off.
I have had several A/C mopars that work that way. The most recent is a '71 Superbee.

Omni

 

[Chargered]

When you push in the "Off" button (pushing in towards front of car), it should shut down completely, right? However, when I push in the Off button, it does slow down but doesn't stop completely until I pull the Off button back towards the rear of the car. I don't think its normal to have to pull the Off button back again, after you have pushed it forward........or am I mistaken?

 

[Hugh Jass]

When you push off,all should be off. It seems to me you have a feed back issue, or faulty push button switch,start with a jumper to ground on your blower motor, see what happens. If still happening, probe your push button sw. when you turn it off with a test light see if its sending power to blower circut. Then reply with results and we will go from there..

 

[Chargered]

Thank you for the help Hugh. Electrical is not my area of expertise. I understand putting a test light on the off button switch to see if its still sending power. However, I'm not sure what you mean by "start with a jumper to ground on the blower motor". Are you saying to run a ground wire jumper to the power side of the blower fan or to the ground side. Sorry for my ignorance, but like I say, I'm not very knowledgeable on electrical stuff. Thank you, Ed.

 

[Chargered]

Tonight I ran a jumper from the blower motor to the negative side of the battery terminal and still had the issue where the fan turns very slow even when I push the Off button. I'll try probing the Off push button tomorrow.

 

[Chargered]

Today I put a probe on the Off Switch. When I pushed the Off button, it still had power, then I pulled the Off button back and no power. I think that is telling me I have a bad push button control switch???

 

[Hugh Jass]

Sorry for not responding sooner. It sounds like you have gone about your diagnose like a pro. That is what I meant,jumper a wire to a mounting screw on the metal fan case to a ground. Without being there it sounds like you have zeroed in on the problem. The switch is either worn or some chinese made dung and the off position is a crap shoot. Let us know how you made out. Hugh

 

[Omni Source]

Good Morning

I had owned several Mopars (Mid 70's) that had the push button set-up. In order to shut down the AC system you did indeed PULL the off button toward you. In fact of the bezel it did say push/pull. I belivee that you will find that the ONLY button that can be pulled is the 'Off' button.

The slide switch A/C controlled systems, the fan would not shut down until the slide lever was placed in the 'Off' position.

If you have a service manual (or owners manual) check it.

Omni