Fan driver question
Fan driver question On a 98 ls how are the fans turned on? Wires r43 and b28 are the fan drivers, do they send 12 volts to a relay to turn the fans on, or do they send a ground to the relay? I cant get either fan to come on, getting codes p0480 and p0481. I have them hooked up to two relays with the expectation that they will send 12 volts to the relay to turn the fan on. Am I missing something here?
Staging Lane
Joined: Sep 2008
Posts: 92
Likes: 1
The fan relays are controled by the PCM by grounding the relays. Wire 43 turns on low speed(fan relay 1) and 28 is high(fan relays 2&3). Check for a constant 12 volts at terms 85 and 30 of fan relays 1 and 2. Put a jumper to ground from term 86 and the relay should click. If not, grab a different relay and try again. When operating, the fans do a funky thing of running in series at low speed and running in parallel on high. This means all connectors must be in place to work properly. Low speed will not work if one of the fan motors is burned out or disconnected. Check the stickys for wiring diagrams. Post your findings to help others.
