Hey guys,
So I've been trying to figure out which wire I should splice into to get my electric fans to kick on when I turn on my a/c?
so far I've had no luck.
any suggestions?

Relay it to the ac switch wire?

So you're suggesting I run a wire all the way into the cabin? isn't that a little much I have a wire for it coming off the relay thats set up to my themo switch to kick on the fans at a certain temp. theres got to be a wire in the engine bay that would kick it on. needs to be a power wire. I tried to run it off the two wires coming from the compressor plug and they both gave me a neg volt dc volt reading when I ran it from the positive terminal to both of the wires and gave no reading when I ran it from neg term to the wires. if one was a power wire and not a ground they would have gave me a positive reading if placing the pos lead of the voltmeter. but when I did it gave me a neg reading. so what wire would give me a 12v source only when the a/c is on?

Esenpai wrote:So I've been trying to figure out which wire I should splice into to get my
electric fans to kick on when I turn on my a/c?

You need to be more specific.
- Do you want the fan to switch on any time you turn the A/C ON using the
dash controls (compressor running or not) ?
- Or do you only want the fan to turn on when the compressor runs ?

The first one is a bit tricky, but the second option is easy. As you have said,
just pick up a 12V signal from the compressor clutch power wire. One of those
wires you tested will have 12V on it when the A/C Amplifier is telling the
compressor to run. Test it with the A/C compressor running.

Cheers... jondee86

jondee86 wrote:

Esenpai wrote:So I've been trying to figure out which wire I should splice into to get my
electric fans to kick on when I turn on my a/c?

You need to be more specific.
- Do you want the fan to switch on any time you turn the A/C ON using the
dash controls (compressor running or not) ?
- Or do you only want the fan to turn on when the compressor runs ?

The first one is a bit tricky, but the second option is easy. As you have said,
just pick up a 12V signal from the compressor clutch power wire. One of those
wires you tested will have 12V on it when the A/C Amplifier is telling the
compressor to run. Test it with the A/C compressor running.

Cheers... jondee86

yeah weird thing is they both give me the same reading....maybe I should test before the plug? i was doing it after the plug, the wires on the harness side not the compressor side. so maybe that makes a difference? Though that doesn't make sense.

Power only gets on the circuit when the relay that controls the A/C clutch
closes and puts 12V down the wire. At all other times the A/C clutch and
the wires in and out are at ground potential. So if test the wires to ground,
you will get zero volts. You will only get 12V when the A/C relay is closed
and the clutch is powered up... then you will get 12V on the supply wire
and zero on the other wire that connects to ground.

Cheers... jondee86

jondee86 wrote:Power only gets on the circuit when the relay that controls the A/C clutch
closes and puts 12V down the wire. At all other times the A/C clutch and
the wires in and out are at ground potential. So if test the wires to ground,
you will get zero volts. You will only get 12V when the A/C relay is closed
and the clutch is powered up... then you will get 12V on the supply wire
and zero on the other wire that connects to ground.

Cheers... jondee86

ahh I see that makes sense. Thanks Jon