I need a wire up my trans cooler fan and I wanted to wire it to something that is turned on by the ignition does anybody have any suggestions on which wire I could use in the engine compartment tha wont take away from needed voltage somewhere else.


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1992 383 Z-28 w/SuperRam intake and ACCEL DFI, PA Racing K frame,SS hood,SS rims

 

I have a 1991, and on the fuse block, there are two sockets directly below the gauges fuse that will accept a 1/4" male spade plug. They are hot with the ignition "on", and powered through the 10 ampere gauge fuse which power a lot of low current things like the gauges (duh), convenience center audio alarm assy., VSS buffer, EGR solenoid assy., daytime running lights module, and so forth. I wouldn't want to use more than a couple amperes though. Actually, I wouldn't use it at all. I'd use a relay.

The best way would be to use a relay to switch the fan on/off to increase the switching current capability. That way, you'll need less than an ampere to power the relay (via the coil) which can be taken from any point that has +12 with the ignition "on" (see above for one example). One relay contact connects to the battery (or the starter solenoid where the battery cable connects, or other location), the other relay contact to your fan motor positive.

 

Sorry, I forgot you wanted a wire in the engine compartment.

Without knowing how much current the fan draws, I would only go the relay route unless it's a 12VDC muffin fan, in which case it'll draw less than an ampere and you could use the positive wire that supplies +12 to the ignition coil (in my 1991 manual, it is a pink 12 gauge wire at the coil).

This is one point where you want all the voltage you can get (for the hottest spark), so again, I recommend you use a relay to operate the fan, and use the pink wire to control the relay through its coil (the contact of the relay directly to the battery via a fuse of the proper rating).