the wire that we splice into the switch for this mod is it powered? so i can run an LED off it to say when its on or off? anyhelp would be great thanks!

 

If there is electrical current running through it when you have the switch on, I would *assume* so... But other than that I don't know...

-TJ

 

i should ask is it a negative feed or a positive feed wire? i have a really nice 5000$ electrical tester i should try out but its too cold to sit outside and do it haha..thanks for anyhelp!!

 

Yes, the purple wire is hot when the HVAC mode switch tells the PCM that A/C compressor operation is permitted. To monitor it after doing the switch mod, you would want to tap it between the new switch and the PCM.

Monitoring the purple wire won't tell you when the compressor is actually running though. If that is what you're looking for, then you would need to tap the gray/white to the compressor clutch instead.

 

just the man i was waiten for to respond i knew youd see this haha! ok question for you bob i havent done this yet but i will be doing it tomorrow..this gray white wire you talk of its in the HVAC panel as well? and if i tap an LED into this it will say when its on or off? or is it easier to put the positive wire of the LED on the other side of the switch so when i turn on the switch the light turns on so i know ive turned on the compressor? or would it be smart to run one light off both? any good comments about thie mod i should know about??

 

The purple wire goes hot when the HVAC mode switch is in one of the 5 A/C-enabled modes. The PCM interprets that voltage as "permission" to ground the A/C clutch relay. That doesn't mean that the PCM will actually ground it, only that it is permitted by the switch position. There are other conditions that must also be met before compressor clutch engagement can occur.

The gray/white goes hot to activate the compressor clutch solenoid. Monitoring it will tell you every time the clutch is actually commanded to engage.

The gray/white clutch wire is only available under the hood in the harness between the electrical distribution box and the compressor.

 

ahhh i got ya..well ill toy with it tomorrow hopefully my AC works when im done LOL

 

I know this is an older thread but I was trying to figure it out as well...

I already have the switch which is a SPST, but I was going to tap the purple wire from teh switch and then a common ground for the LED. I need to see how much voltage the switch wire is putting out so I can get the correct resistor...

I hope to start this over the weekend while I am doing other things and doing my suspension, I'll post and update once it's done.

-Nigel

 

I successfully added the LED. Looks stock honestly. If you didn't know what you were looking at you'd never know it was there. I'll post pictures tonight. But now when you flick the switch on it will illuminate an led indicating that the AC is on. Flick it down and it's in manual mode and off.

FYI: The control wire on my truck was putting out 11.8v. I read somewhere that someone stated 3-4v. This was not correct in my case.

-Nigel

 

Darn it Nigel!

 

Pictures as promised.

You can see in the vent/foot mode that I can switch the ac on/off... I dig it. Doesn't look out of place and isn't too bad.

-Nigel

 

Looks great, very clean install. I may have to do this myself.