: Switched ignition source under the hood



tabascotk
07-14-09, 03:51 PM
I need to find a wire or source that is switched with the ignition for my electric fans. Does anyone have a good spot for me to get this from? Also, I need the clutch wire for the a/c so the fans will turn on with the a/c. Any help would be great.

sfv41901
07-15-09, 04:09 PM
The best thing you can do is get a light tester & check which fuse lights up with the ing & tap into it.

tabascotk
07-15-09, 04:21 PM
Yea, I hate that trial and error stuff. But if it has to be done...

sfv41901
07-15-09, 11:26 PM
Yeah, I know, its a PITA. Helps when you have someone to help. Good luck.

tabascotk
07-16-09, 07:54 AM
I just remembered that I have a friend who is a mechanic. He's going to print off some wiring diagrams for me, that should help find a good source.

sfv41901
07-16-09, 01:17 PM
That should help alot.

Post them if you can. I'm sure it would help alot of people here.

sk7
07-22-09, 05:59 AM
Did you find what you were looking for? I got the GM SI DVD from BlownC5, I can post diagrams needed for your truck. This software is a must for any cadillac owner.

tabascotk
07-22-09, 09:32 AM
Did you find what you were looking for? I got the GM SI DVD from BlownC5, I can post diagrams needed for your truck. This software is a must for any cadillac owner.

I did find what I needed. I took my meter and checked for voltage on the a/c clutch wire. The hardest part about that was getting the connector off so I could test it. It goes much faster if you have someone in the cab to turn the a/c on and off. I didn't have anyone around, so I had to run back and forth. FYI, If you're looking for that wire, there are two wires that plug into a connector that runs into the compressor just behind the pulley. The wires are green and black. The trigger wire for the a/c is the green one.

Then, I found that I have a switched source for a rear wiper, but the EXT doesn't have a rear wiper so I pulled the fuse and used the hot side of that. Now I just have to put an in-line fuse for that and the whole setup will be done. I'm not overly concerned about that just because it's not pulling power from that to run the fans, it's just looking to tell the relay that the truck is on so start the fans when it gets hot enough.

So, the fans are finally in. The hardest part about that whole process was getting the stock fan off. After that, everything is pretty easy.

sk7
07-22-09, 04:02 PM
Glad you got everything hooked up! Why did you replace the factory setup? Post pics if you can.

tabascotk
07-22-09, 04:38 PM
I'll see what I can do to get the pics posted. I replaced it just because it was something I wanted to do. I've heard it can give better performance and mileage gains. So I decided I would do it and find out for myself.



Glad you got everything hooked up! Why did you replace the factory setup? Post pics if you can.

sk7
07-22-09, 08:03 PM
I've also heard that one too. Let us know if you see a difference. I also heard that electric water pumps are nice. They do require a bit more work in mods to the belt system. Maybe kits are available to make the job easier? Was the fan kit made for GM trucks or you had to fab a few pieces to make it fit?

tabascotk
07-23-09, 08:21 AM
I'm taking a trip from Minneapolis to the Quad Cities area next weekend. That should tell if there really is an increase in the mileage. Right now I will say that I noticed a little difference when accelerating, and it seems to coast for longer stretches now.

I actually bought the kit from a seller on ebay. Pretty much all they deal with is electric fans kits and radiators. The kit came with 2 fans, and all the relays needed to make it work. It was about $300.

sfv41901
07-23-09, 05:52 PM
There really isnít any HP gain with this mod. There will be less resistance on the motor, so you might feel more throttle response. Iím not too sure if you will see any big changes in your MPG.

This is a popular mod on the E36 BMW M3 as its plastic fan has a history of breaking & going through the hood. I never noticed any change in HP or MPG, but there was more throttle response.