Custom headlight/fan relay harness build

[StarquestMan]

So for the fan mounting, I did have to modify the support bracket that goes right behind the grill. It is easy to replace, since it is held on by just 3 bolts, so its not an issue for me if I decide to do something different in the future. here's how I did it.

You can see where I cut the bracket. I forgot to get a picture of the finished part, but I just bent in the 2 sections and welded them up and filled in the resulting gap with a piece of sheet metal cut from the piece I cut out from the bracket.

Here is the fan. I removed almost all the mounting points except for the one that the fan motor connector clips to, it actually got used as a mounting point later on by installing a rivnut in the hole on it that sits at an angle. I utilized the rubber mounts that came with the fan by cutting and welding them to different spots as seen in the following pictures. also note the bracket that attaches to the condenser. This uses the existing screw holes in it but with slightly longer screws to reach the threads in the rear of the condenser.

The fan relay I decided to control with the Idle up solenoid. It gets its power from the same circuit as the compressor clutch, but on the 87-89 pickups, its ground is controlled by the ECM. this means that once the engine is above a certain RPM or throttle position (I'm not exactly sure which), both the idle up solenoid and condenser fan turn off. This is good for fan wear, relay wear, fuel economy, etc. I had asked about different options in a different thread but decided to go with this option for now at least. It does seem to work good so far. I simply made a "T" harness that puts the fan relay coil in parallel with the idle up. Speaking of relay wiring, I decided to use one of the big relays for the fan and the other big one for the high beams, this leaves the smaller relay on the low beams. The smaller relay has plenty of current capacity for the low beams and the fan, I'm sure, has a pretty large current draw on startup. This should prevent any of the relays from failing too soon.