Ok, i have to get 12V 20A from the fuse box that is only hot in run. iv looked at wiring diagrams that have the fuse box in them, but i cant fint a detailed wiring diagram for every wire into and out of the fuse box. im going to be splicing a wire into it and im just wondering if someone can tell me the best wire from the fusebox to do this. Iv never played with it before except changing fuses.

any replies make me happy, thanks

 

What equipment are you going to be running?

 

Look at the fuse panel. (there is a picture on this board somewhere of a fuse panel too)

Any of the spare "slots" that only have one connector in them, are viable candidates. Some are 12V battery, (constant) some are ignition switched. Find the circuit breakers on the fuse panel, those are what control those terminals, thus their rating is what is at those terminals. Typically 30amps, although you can buy 20's, etc.

The smart way to do it is pull the power from the correct accessory terminal, and run an inline fuse off of there. Those terminals use locking connectors, if you want a clean troublefree connection, any GM that vintage will be a donor for those wire connectors, just cut and splice a lead to your inline fuse holder.

Even if the labeling is intact on the panel, I'd still use a voltmeter to make sure the terminal has voltage when you want it.

 

Why not just plug into the power junction block that is located above the hood release cable behind the left kick panel. It is known as connector C238, it is 12 volt 20 AMP constant power. Here is a picture of it.

 

thanks for replying, what i needed was to run a 12V feed wire to a SPDT switch for my fan, i have it wired the same way as described in Willie's fan control article. theres the adjustable relay controlling the fan if the switch is off, then one way on the switch manually turns the fans on, the other way disables the new relay and goes to stock settings. a little diagram of this circuit shows the feed for the switch comming from a 12V 20A source from fuse box, your choice hot in run or always hot.

so i ended up using one of the 2 or 3 acc. spots that are hot in run. those are what have the cicuit breakers above them if im understanding that right, so should i or should i not add another fuse to this wire before my switch? are all the acc. spots comming off on one breaker?

thanks and sorry if thats a long way of describing everything.

 

If someone has the actual fuse panel wiring diagram they can post (don't believe it's in the electrical manual, at least for '88) then you can pretty easily tell which terminals are fed how.

The other 80's GM fuse panels I've seen gang all the accessories up under one or two 30A breakers, which you could theoretically overload if a lot of accessories, or which may not provide the circuit protection you need.

I'd run an inline fuse to bring it to whatever rating you need.