Blue_Thunder

iTrader: (1)

I have a 86 Iroc with a transplanted 89 350 in it. And my fan setup is currently stock (single electric fan). I will be switching thermostats soon (to a 160) and I need to be able to change when the fan comes on. I have been reading that 86 is what seems year specific as it does not use the coolant fan switch on the passenger side head to control when the fan comes on. I have the original GM shop manual for this car and the wiring diagram shows a coolant temp sensor (2 wire). Is this what controls when the fan comes on? Where is it located?

Basically what I am looking to do, is install a 160 thermostat and have the fan turn on at 210ish and off at 190.

How do I go about doing this as I don't have the wiring for the fan switch in the passenger side head?

Do I have to reprogram the ECM?

camaronewbie

In my opinion, the factory style fan switches in the pass side head are terrible - they always fail, and you get covered in coolant replacing. If it were me, I'd get an aftermarket fan controller than probes the radiator fins. I run a Flex-a-lite controller, cost me $100 - but worth every penny. Easy to wire in, doesn't use any stock wiring (except for fan pigtails), fully adjustable temp range settings, provisions for A/C as well as a manual always on switch. I've been running mine for 5+ years now with no problems at all, works exactly as it should every time. And I can adjust on/off settings for winter vs. summer months in about 5 seconds.

Blue_Thunder

iTrader: (1)

So, how would that work with my ECM? or, would my fan not be controlled by the ECM with this kit?

camaronewbie

Takes control away fro mthe ECM - aftermarket controller does it's own thing all by itself - nice because it eliminates potential problems - all you have is a controller, and a few wires to the fan, and a probe for the radiator - no more guessing when/if the ECM will ever turn on the fan. And adjustable, so YOU set the temp range based on YOUR car and thermostat options (which by the way, I wouldn't run any lower than a 180 stat, and wouldn't set fan on temp any lower than 200 for a car still computer controlled - the computer will see lower temps, think the car is too cold, and richen mixture making it run rich and poor gas mileage).

Blue_Thunder

iTrader: (1)

So the ECM is removed from the circuit completely and won't interfere with a fan controller wiring harness?

And, I would be getting a 160 stat but still have the fan turn on at say 200 and off at 190.

But, I am still considering, I may end up keeping my 180 stat.

jeff_blake

iTrader: (1)

+1 on the flex a lite adjustable fan controller. well worth the money!

4U2ENVY

So I have a 85 Iroc and have the same heating up during slow speed problems. I ordered the summit fan switch and went to install it today only to find out that i didnt have one also (after removing the knock sensor) and draining all the coolant out. So I called up the local Carquest and got a fan controler which is the same as mentioned above for only 36 dollars but when i went to install it the damn probe wires were cut....

im so pissed this is the seond time i tried to fix it and it never works out.

oh well