86 cooling fan computer controles
Thread Starter
Heel & Toe
Joined: Aug 2016
Posts: 22
Likes: 1
From: Hempstead TX
86 cooling fan computer controles
I have been experimenting with the cooling system on my 86 and installed a 180' thermostat and a PCM of NC tune with lower on/off sets.
I also installed an on/off indicator light on the fan to monitor operation while driving. When I drove the car to check operation the fan came on
at vehicle speeds above 35 MPH regardless of coolant temps.
Is this normal, it doesn't seem logical to me. I don't want my fan to run when not needed and if it is supposed to to be turned on by speed it seems to me ON under 35 would make more sense than over 35. PCM said they could only modify temp. sets and were not aware of speed sets one way or the other.
I also installed an on/off indicator light on the fan to monitor operation while driving. When I drove the car to check operation the fan came on
at vehicle speeds above 35 MPH regardless of coolant temps.
Is this normal, it doesn't seem logical to me. I don't want my fan to run when not needed and if it is supposed to to be turned on by speed it seems to me ON under 35 would make more sense than over 35. PCM said they could only modify temp. sets and were not aware of speed sets one way or the other.
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
An '86 according to the FSM fan should "turn-off" at VSS speeds of 40 MPH if none of the other requests(OVERHEATING) are met. I've never seen anyone mention that the speed was "programmable" - Is the VSS and gear(drive/driven) combination correct for the axle ratio and the tire dimensions.
Have you mentioned this maybe previously? The request just looked familiar as I was typing.
Some years mention the 35 MPH for VSS - I didn't check an '86 supplement for information.
Have you mentioned this maybe previously? The request just looked familiar as I was typing.
Some years mention the 35 MPH for VSS - I didn't check an '86 supplement for information.
Thread Starter
Heel & Toe
Joined: Aug 2016
Posts: 22
Likes: 1
From: Hempstead TX
Have not posted about this. the odometer does not work and i have not traced problem yet. The car is automatic coupe no performance options stock (gear, tires, cooling, L89) except 160 thermo and PCM chip. Chip: del EGR and Speed Limit, set fan of/on at 185/190, 93 octane street tune. I installed fan on indicator with chip and thermo so I have no info before but after I installed chip the fan ran any time the speedo read over 35 and went off when speed droped below 35 unless temp was above 185.
Last edited by some0ne49; Nov 16, 2016 at 11:30 AM.
Safety Car
Joined: Sep 2004
Posts: 3,953
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From: Mission Viejo CA
Thread Starter
Heel & Toe
Joined: Aug 2016
Posts: 22
Likes: 1
From: Hempstead TX
How did you wire the on/off indicator light? Is the light wired to the fan motor, or is the light wired to the fan relay control signal? If you wired the indicator light to the fan motor, the speed of the wind coming thru the radiator will cause the fan to spin, which will cause the fan motor to act as a generator, which will turn on your light.
