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Old 03-16-2015, 02:16 AM   #1
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Default 89 Supra - Cooling Fan Relay - Please Help


I have an 89 Supra (Non Turbo) and I started having overheating issues. I have done many processes to fix this problem.

Initially, The car would overheat showing me on the temp gauge which was on or close to red. Now the gauge doesn't go past the half way mark, but I feel that the engine is still heating past the normal level and idles rough.

One thing I've noticed, is that the cooling fans do not turn on at all. I have tested them by connecting them directly to the battery, and the turn on. Then I created a jump (Bridge) on the cooling sensor connectors and the fans do not turn on.

The only thing I think needs to be done is to change the fan relay. but here is the problem. I've purchased the new relay.....but I can't find where it goes. I have looked at many diagrams and have followed the cables and I just don't see where it needs to connect. The relay I purchased is a round cylinder looking part. I do see there are 2 square type enclosures close to the battery that are connected to the fans. Could those 2 be the relay(s)?

This problem started with my reservoir tank overflowing with steam and the car overheating.

Here is what I've done to the car to try to fix it

Changed Thermostat - Same issue
Changed all the heat sensors - Same issue
Radiator Flush - Same Issue

Can I please get some guidance on where I can find the Fan relay? Maybe I'm not looking at the right diagram, but I've checked so many of them and none of them show the location of a round cylinder looking part as the relay.

Thank you for your time.
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Old 03-18-2015, 01:19 PM   #2
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The electric fans on these cars are designed to come on with the A/C to provide extra cooling. If your stock clutch fan on the water pump is not providing sufficient cooling, then you have additional problems you need to address (anything from weak fan clutch to blown bead gasket).

With that said, there are up to 3 A/C condesnor fan relays on the supra, depending on engine transmission combinations. All supras should have the primary relay, located next to the battery. You may also have up to 2 more located next to the air filter. See parts A11-A13 in the attached diagram

1989 7MGTE R154 Targa Top White Package w/Blue Interior
Driftmotion 57trim CT26, Upgraded Intercooler, 2.25" Hard Pipes, 3" Turbo Back Exhaust with Test Pipe, HKS VPC w/GM 3 bar MAP sensor, APEXi S-AFC, Walbro 255lph fuel pump, ProSport EVO Series Boost / Fuel Pressure / AFR gauges, Lotek a Pillar Gauge Pod, HKS Type 0 Turbo Timer, Eibach Lowering Springs, Tokico Illumina II TEMS struts, custom powder coated Motegi Racing TrakLite wheels
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cooling fan, cooling system, overheating, relay, sensor

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