1bad86

My single electric fan isn't coming on when it's supposed to. It will come on when the A/C is turned on but not automaticly like it should. Is it the relay or what? Also what is the normal temp. the fans should kick on with a T.P.I car

Thanks,
1BAD86

John 89 Formula

It's most likely a bad coolant temp sensor.
The cooling fan motor gets its power directly from the relay, so if the fan works with the ac on, there is nothing wrong with the relay. When you turn the ac on the relay is grounded through the pressure switch and turns on the fan.
Also most 86's do not have a fan switch, the ecm controls the fan based on information from the cts.
With a stock chip the fan will turn on at about 240 and off at 220.

1bad86

ok thanks, so where is the coolant temp. sensor at?
also I bought a new relay just incase. and last night I bought a new temperature sending unit for the gauges right. well when I took my old one out it had the round ball like "probe" on the end instead of the straight "probe" that the wire plugs in to. and from looking at pitcures at advanced auto.com the rounded probe one is the fan control switch so I'm thinking mine does have a control switch, and the sending unit and control switch got switched around.
Any ideas????

Thanks,
1BAD86

John 89 Formula

The cts is in the intake manifold just behind the alternator, there are 2 switches there, the cts is the one with the yellow and black wires on it.

The guage sender is in the driver side head between the 1 and 3 cylinders.
the stock one has a small flat disk on the end about 1/4in diameter and the connector slides over it, it's a white plug with a 1/4in female spade term on it. Most aftermarket ones have a spade connector on them.

If you car does have a fan switch, which I doubt, it is located in the passenger side head between the 6 and 8 cylinders.

91 Ragtop

I will have to check this out myself. I just discovered a couple of days ago that in the Trans Am I just purchased, the previous owner had "hardwired" the fan to the fusebox......