Anyone have a factory wiring diagram for a 1987 iroc? The previous owner completely hacked the wiring harness so I need to get that repaired.

Any recommendations on repair manuals to purchase??

Thank you

 

Engine wiring diagram, 87 305 TPI. Fan wiring is bottom right of the page
http://austinthirdgen.org/mkportal/m...ine_wiring.gif
You can make your own harness and use a temp switch for different on off temp as well.
https://www.thirdgen.org/forums/cool...fan-right.html
Check ebay for factory service manuals, obviously the best choice.

 

Thanks. I just found that. It seems pretty basic. Im assuming the coolant temperature sensor tells the computer when to flip the relay which in turn, turns the coolant fans on.?

The PO cut that all out and wired in a hard switch because the car would over heat. So instead of diagnosing the issue, just bandaid it...

 

Or look here:

Lots of diagrams (page 12)

 

The sensor in the drivers side head between 1&3 spark plugs is solely for the gauge. There is a sensor in the intake coolant crossover by the thermostat housing that gives the temp to the ECM which grounds the green/white wire on the relay to turn the fans on. The biggest problem with "overheating" is people not understanding the high temps these cars were designed to run at. Next in line is a missing air dam under the car that should be mounted to the core support. It creates a low pressure area behind the radiator and gives more air flow through the radiator at driving speed.

 

1991 and a 1987 fairly different?

 

Not really, just where it connects to the 'puter

 

As Joe Tag mentioned,

Installing a fan switch with a lower setting than the stock 235*"on" is one of the first mods that IMO should be done.

The last thing I would want is to be running my car at temps so very close to red line, even if they were designed that way.

A 195* switch with a 180* thermostat will help keep the car in the 200* range and lower.

Perfect for most.....