LS1 Fan Wiring + Side Indicator

[Aussie Mike]

Hi Bruce,

In the LS1 loom the BCM controls the low speed fan and the ECM controls the high speed fan. The BCM switches the low speed fan on when you turn on the AC etc and it also kicks on at a lower temp. The High speed fan is a backup that the ECM can turn on if things are getting a bit too hot. It doesn't come on till about 95 degrees which is a bit to hot for a regular fan.

I reccomend use the high speed fan output from the ECM . This is switched earth not switched battery like the fuel pump control so when you wire up your fan relay supply accessory or ignition battery to the relay and let the ECU provide the earth to switch the relay on.

When you get your ECU re tuned (talk to Plums) get him to drop the on temp of the high speed fan from 95 degrees to about 85 and this will work a treat. There is some hysterisis built into the high speed fan control so it's not always turning on and off. It has an on temperature and an off temperature. Set it to come on at something like 85 degrees and turn offf again at 82 or something like that. The figures Bobby and I used seem to work OK so try them.

Check out the late model Ferrari side indicators. They will probably set you back about $75 for the pair but they look great and are easy to fit and dont require any special plug.

Cheers