am

I changed my belt driven fan to an electric one and i wandered if the thermo switch , located in front at bottom left corner of the main radiator that is used to drive the A/C fan , would be good to drive my radiator fan ? (question of degrees ?)

spode134

If you use a relay and switch the supply to the fan with a grounding circuit you can have a switched ground from the thermo switch and a toggle switch that does the same. This way you can manually control the fan. A trick thing to do is run a lead back from the switched 12v side of the relay back to a light or 12v led on the dash, this way you can see when your fan comes on. Also it's nice to have the supply to the relay be constant 12v.
As for the switch being the right temp, try it and see, you may find it cycles the fan on and off more than you like.
Darrin.

SharkSkin

That would be as good a place as any, but that circuit might not support two fans. Consider using that to drive a relay for your second fan. Another option is to get a separate thermo-switch that goes between the radiator fins, and set it for a slightly different temperature so you effectively have a two-stage fan setup. When it gets a bit warm, one fan comes on. When it gets a bit warmer, both come on.

Jim bailey - 928 International

Be sure to use a fuse in the new circuit and a relay. The radiator switch temp stock is about 92C which is usually about the top white line on your temp gauge . As Dave mentioned a second lower switch is a better option since it stages the fans and reduces the electrical draw on your charging system.

am

Thank's to all for advices , i forgot to mention that i deleted the A/C system because it was not working and around here the summer is so short ! and the car won't be a daily driver so i took out everything from A/C. So i wanted to use the circuitry of the A/C fan but using a constant +12v
Could you please tell me where i could find the switch i could put on the rad ?

cdbtx

Summit Racing and I'm sure others carry a thermo switch/relay assembly for electric fans which allow you to adjust the temp settings and control other devices such as an A/C fan. The switches typically come with a fan light indicator lead too.

If you've removed everything from the AC, why don't you simply remove the A/C condensor which will allow more air flow and you'll never have to worry about needing the 2nd fan.


Chuck


83 Kiln Red 928S

am

The A/C condensor has been removed , i want to use the circuitry (relay) of the A/C fan to drive only one fan now Chuck.
Thank's i'll try to find a thermo switch

Jim bailey - 928 International

If your condenser is removed you should move the front fan back close to the radiator or much air flow will escape through the gap.

SharkSkin

Agreed - either move it back or extend the shroud. It can be extended easily with some flat strips of aluminum roof flashing wrapped around the shroud and fastened with pop rivets, or of course you can get as fancy as you want.

am

I'm okay with the fan , i found a nice 5 blades fan and fit it at the place of the original one without too much work , most of all i did'nt want to modify the look too much. I will try to find that adjustable thermo switch and i'll be back in business
Thank's