Anybody know how to wire the fan/fans to a switch?

[Blacked_Out_SS]

My fans are not coming on at all. Even when turning on th a/c. I'm tired of buying sensors and relays and just want to wire them up to a switch so I can turn them on when needed... The car is a 97 ssei with 217k on it. Anyone have a wiring diagram that shows how to do this? Thanks in advance.

[RJolly87]

If you are looking for a wiring diagram so that you can defeat the control the computer has, you may be better off tracing the wiring to see what is going on. There is a number of ways to do it, but many depend on wiring that is already in the car.

If you want to go full manual, Cutting the plug at the end of the fan harness and wiring your own relays up would accomplish this.

I recommend against going full manual, because it's very easy to invite problems with overheating and A/C, especially when someone else is involved. The PCM works by grounding the trigger pin in the associated fan relay.

Bypassing the PCM control without knowing the exact point of failure is unwise. A scan of live data, and even a scan tool that can command fans on will help you immensely in your quest to track down the failure.

[96 SSEi]

hi, best to get a thermostatic resistor to cycle the fans
like these....https://www.summitracing.com/int/search ... ator-probe
but you can run a wire from power to the positive connection of the fan.

the fans pull high amps so the wires/switch have to take the current.

on my 96, if you put it on the - wire, it spins backwards - bad for cooling at speed

[Wes]

If you have already replaced the sensor and relay, there's not much left to do besides the wiring and the fans themselves. Which if they were dead, a bypass would do no good.

Have you already tried to run 12V directly to the fan(s)?

[skregal]

To make the high speed fan work manually you can splice into the
dark blue wire (circuit #473) that goes to the white 32 pin PCM
connector at position (WD10). Run it to a ground with a switch
mounted in between, and you can use the switch to turn your
high speed fan on and off.

[J Wikoff]

On my 92, I wired a switch to ground the ground wire for the high speed fan relay on the firewall. I think it is effectively the same thing skregal said. Have you checked for power and ground to the relays, low and high?