Fan Relay Question in Stand Alone Harness
Fan Relay Question in Stand Alone Harness OK well I got my harness modded and all seems well. However the fans dont seem to be right in high. In low the one kicks right on and spools up very quickly. When I go to high, the relay will buzz a second or 2 while trying to engage and then both fans will spool up slowly(at least compared to the 1 turning on). My question is, is this because of the fans not getting enough power (running 1 10ga wire to the relays) or an overrated relay? They are supposed to be 30a/40a. Thanks!!
I beleive the fans have three different operating modes. One relay operates them both fast. One realy operates one fan fast. Both together operate both fans together fast.
I think this is right. I don't have the diagram in front of me right now.
Re'
I think this is right. I don't have the diagram in front of me right now.
Re'
The fans have 2 modes. Slow and fast. The stock setup uses one relay to contol both fans in series so each fan gets about 6V and runs in slow speed. When fast speed is desired by the PCM, the other two relays engergize and the fans shift to a parallel line up with both getting 12V and they run in fast speed. Both fans always operate at the same speed.
OK well I messed around and figured everything out. When the low speed wire is grounded, one fan will come on but in high speed. I assume this is for the ac. When the high speed grounded, both fans come on in low speed. When both high and low speed wires are ground, both fans come on in high speed. I guess this is how it is supposed to be. I ran it according to the wiring diagram in the faq section. I dont see how it could be wrong but if it is...... 
Sounds like your fan relays are wired wrong. If low speed signal is ground and high speed isn't, both of my fans come on in low speed. If both high and low signals from PCM are grounded, both fans run in high speed. Never tried only high speed signal--the PCM won't do that.
My wiring is based of the '99 factory schematic, modified to run off hot in start/run instead of BAT (I hate surprises under the hood like fans turning on with the key off!)
Relay 5 - FAN1 – Left fan
Terminal 85 Hot in start or run
Terminal 86 To pin J of connector C100
Terminal 30 To 20A fuse and battery voltage
Terminal 87 To Left cooling Fan pin B
Relay 6 - FAN2 – Right fan
Terminal 85 Hot in start or run
Terminal 86 To pin H of connector C100 AND Terminal 86 of FAN3 relay
Terminal 30 To 20A fuse and battery voltage
Terminal 87 To Right cooling Fan pin B AND Terminal 87a of FAN3 relay
Relay 7 - FAN3 – speed control
Terminal 85 Hot in start or run
Terminal 86 To pin H of connector C100 AND Terminal 86 of FAN2 relay
Terminal 30 To Left cooling Fan pin A
Terminal 87 To 20A Ground
Terminal 87a To Right cooling Fan pin B AND Terminal 87 of FAN2 relay
My wiring is based of the '99 factory schematic, modified to run off hot in start/run instead of BAT (I hate surprises under the hood like fans turning on with the key off!)
Relay 5 - FAN1 – Left fan
Terminal 85 Hot in start or run
Terminal 86 To pin J of connector C100
Terminal 30 To 20A fuse and battery voltage
Terminal 87 To Left cooling Fan pin B
Relay 6 - FAN2 – Right fan
Terminal 85 Hot in start or run
Terminal 86 To pin H of connector C100 AND Terminal 86 of FAN3 relay
Terminal 30 To 20A fuse and battery voltage
Terminal 87 To Right cooling Fan pin B AND Terminal 87a of FAN3 relay
Relay 7 - FAN3 – speed control
Terminal 85 Hot in start or run
Terminal 86 To pin H of connector C100 AND Terminal 86 of FAN2 relay
Terminal 30 To Left cooling Fan pin A
Terminal 87 To 20A Ground
Terminal 87a To Right cooling Fan pin B AND Terminal 87 of FAN2 relay
