evileddy

I have a 1975 ford landau and i just fitted 2 x 10" thermo fans in it, do i run the fans straight from the battery or is there somewhere else i can run the pos wire from? If i run straight from the battery the fans are running at very high revolutions and they stay on when i turn off the ignition. will this flatten my battery after a while? I have tried running the fans from the pos terminal on the coil and they run at what seems like a much more relaxed speed and also turn off when i turn the ignition off, will running the fans from this terminal cause any damage to other components in the engine bay or would this be alright. Please someone help, any advice would be greatly appreciated, cheers.

__________________
"EVERY CREATURE ON EARTH MUST DIE ALONE"

xb351coupe

Mate, try doing a search on the subject, this has been covered heaps of times before. But there is no way in hell I'd run them from the coil....

AUXR8U

flame grilled Landau anybody??

Relays dude, Relays!

evileddy

ok i got it worked out, i just ran the positive wire to the fuse box inside the car and its all good to go . hey auxr8u, classic not plastic. relays shmeelays.

__________________
"EVERY CREATURE ON EARTH MUST DIE ALONE"

XWish Ute

Couple of points here.

Coil uses a sneaky system that switches 12V to the coil for starting, then switching in a really long length of resistance wire to drop voltage to about 7V once the engine is started. Otherwise coil burns out. So if you hook your thermos up to the coil, they will run slower (7V instead of 12) but they are pulling a huge amount of current through a tiny diameter wire only meant to run the coil. Not good for reliability.

Hooking the thermos straight up to the fusebox is also a problem - heaps of current through a box not designed to take it. You run the risk of smoking your under dash wiring, and possibly setting the whole car on fire (once you get a fire going under there it is bloody hard to put out). Remember, these cars never came out with thermo fans! Use a relay to switch power from the battery. and use in-line fuses to the fans to save embarrassing smoke from your wiring loom if the fan(s) shorts.

Now the best thing is to use a thermo switch to control the relay to switch the fans on and off - you don't want them running when engine is cold, only enough to keep it at a good operating temperature. Engine runs more efficiently, and a LOT less load on your electrics. As stated, there are a lot of threads on the subject showing you how to hook them up.

Good luck!