To the vast knowledge on this forum,
I have just installed a Dewitts rad and wired the fans in (1969 cpe). I wired the + leads (30 amp fused) to the horn relay and ran the ground from the fans to the frame my alternator is a 80 amp unit. Check my work photos attached (comments, critisism welcome).
Thanks.

30 amp + leads, horn relay[/IMG]
T'stat wires & ground connection point[/IMG]
Overall view, Mighty Demon 750[/IMG]
27" Rad[/IMG]
1974 L82 stroked[/IMG]
Pontiac blue personal favorite of mine. Brightens the engine bay. (Ray Baker used to paint his engines that color) Western Michigan thing back in the 70's & 80's. Some of you may have heard of him. Baker built.

 

if it works , its good

 

I'm not sure the horn circuit is going to be big enough to carry the load of the fans. you should connect the main fan circuit to the starter or the alternator lug, and the positive for the relay to a circuit that is switch on with the ignition.,

 

Agreed. I wired my hot lead (continious power) to the back of the alternator. I tied my signal to the back up light switch circuit.

Hope this helps

 

OK I'm going use the alterntor lead.
Thanks.

 

You guys do realize that the red alternator lead is also actually wired directly to the horn relay through the harness right? Its just a short little run in the headlight harness that loops over to the horn relay. Horn relay is kind of a misnomer yes it is the relay for the horn but it is all a main battery buss where those two screws are located.. turn over your relay someday and check it out also follow your red wires in your harnesses from the starter and the alternator to see where they go to.

I would say you are better off at the horn relay because the two red wires to the left of your new fan wires are actually the alternator (one coming up from the bottom with the rubber sleeve) and the other red with funky turned 90 degree connector up towards the fender is coming from the starter in the ignition harness.

So I think you are better off at the horn relay with 2 10 awg wires feeding it than one 10 awg wire feeding your fans at the alternator.

Truly the best place for the fan 12v leads is to the battery or to the starter battery lug as that cable is a 0 or 1 awg wire but for convenience you can go directly to the starter lug. Note that your fan wires are both 10 awg with a 30 amp fuse. You could start stressing those fuseable links in the wiring harness if you don't go to the battery in someway through a heavy cable.

 

How did the radiator install go?? Normally they fit fit in like the original. No fighting them like the cheaper ones that are not correct.

 

I am going to run them to the starter lug via 10 awg wire.

 

It went in very easy. My wife helped me with the task.