Electric fan Power wire

[butch27]

I've got my fan relay wired - Blk to the temp. sender- wire to the fan itself- one wire to the fuse box Ign. side ( through a 30 amp fuse) so it will only run when the car is running. The last wire says it goes to Ign. switch. Does this go straight to the keyed switch OR hook it to the IGN feed at the fuse box? Thanks Butch

[enjenjo]

Butch, I am confused. there are 5 terminals on most relays. They are marked with a number 85, 86, 87, 87a, and 30 You can ignore 87a for what you are doing.

Terminal 85 should be hooked to the accessory side of the ignition, at the switch, or at the fuse panel. this is a control circuit, and should never need more than 10 amps. Terminal 86 will go to the sender as a ground for the control circuit. Terminal 30 gets battery power, and should be protected with a 30 amp breaker or fuse. Terminal 87 will hook to the fan power wire.

in operation, with the key on, the control circuit is enabled, but the circuit will not close until the sensor reaches operating temp. When the sensor completes the circuit, the relay will connect the battery power to the fan wire, making the fan run. Wired this way, the fan will turn off with the ignition switch, because even with a ground, the control circuit loses power from the ignition switch.

Clear?

[butch27]

Frank: I'm not using  87a. I've switched 85 to the ground and 85 to the power. I have 30 hooked up to a 30 amp fuse (Constant hot at fuse box) and 87 to the fan motor itself. The only question I have is does 86 (now that it is switched with 85) Does it go to the Ignition key switch or  can I hook up at the  fuse box where the IGN Power side is? Thanks  ( Almost there)

[butch27]

And You just answered my question. Thanks Butch

[enjenjo]

glad to help

[butch27]

Oh I meant that I switched 85 to grd. and #86 to power. Oops one more thing . Do I need two fuses ? one 10 amp and one 30 because I've only got a 30 now on wire #30.

[enjenjo]

Oh I meant that I switched 85 to grd. and #86 to power. Oops one more thing . Do I need two fuses ? one 10 amp and one 30 because I've only got a 30 now on wire #30.

Either way is fine on 85 and 86, unless your relay has a diode in it. The 10 amp fuse is to protect the control circuit, I would run one, but I wear a belt, and suspenders.

[river1]

but I wear a belt, and suspenders.

but that is to protect the general public  :?