How would I put a switch in line with the fans to shut them off when I start the car? Problem is with a DFI, it does not voltage compensate and when the car is hot and I try to restart, the fans come on, take away juice from the computer and no start. So how would I do this?

Thanks

Steve

 

Sorry, forgot to mention the car is a 1991 Formula with the dual fans.

 

There are 3 relays mounted to the fire wall, in the engine compartment, on the driver's side. Two of the relays control the fans & the other relay controlls the fuel pump. The fan relays have a brown wire providing ignition power to the relay coils. If you put a switch in line with the brown wire, (one switch may be used to disable both fans simultaneously, since both relay coils use the same power source) when the switch is open, the fans will not operate, and when the switch is closed, the fans will function as usual. The primary fan relay has a dark green / white wire connected to the other side of its coil, that is controlled (grounded) by the ECM. The secondary fan relay has a gray wire connected to the other side of its coil, that is controlled (grounded) by the temperature switch in the passenger side cylinder head (closes above 238 F) and the A/C high pressure switch (closes above 232 psig), located in the liquid line.

Tim