I believe the retrofit of the EWP circuit over the air pump has messed up the fan circuit. I had the engine going today and up to temp for the first time when temps climbed up to about 230 before I shut it down.

I could not recall hearing the fans kick on, so I created a temporary tune file where the fans and EWP would trigger based on TPS percentage. I set the EWP and low speed fans to come on at 5%, and the high speed fan to come on at 50%.

The EWP comes on, but nothing from the fans.

To begin the investigation I jumped into the service manual and see a reference to fuse 7 on an orange wire that is going to the hot side of the fan relay coil. That explains the fans not activating, but fuse 7 on my cars fuse box on show air pump, where an older fuse box cover shows a/p and fans.

I would think if this wiring was the same in my car that the links would have just tied inside the fuse box, but the wires I cut are going into the loom headed towards the ABS pump.

Is the ‘96 and the ‘97 the same and am I reading the schematic correctly?

 

The water pump should be running whenever the the key is on - whether the engine is running or not. The fans are different and they can be activated by a thermostat when the engine reaches a certain temperature or something as simple as a manual toggle switch that activates the relay.

 

Thanks for the reply. When I started working on this project I had repurposed the air pump fuse and relay for the water pump. The pump relay gets key on power from the feed on the ignition fuse. The Terminator X sends ground to the relay to trigger rather than the ground always being connected. The terminator triggers the ground at 250 engine RPM. I also have a second ground in line from the digital dash configured with a dash button to allow the pump to run with the car off.

That said I mulled over the fan schematic in the service manual and the orange wires that were part of the air pump circuit provided the positive side of the fan relay coils. I reconnected these to the EWP fuse and the fans are now working.

The Terminator X is set to ground trigger the fans in 2 stages based on coolant temp and engine rpm. I might add speed to this later.