Radiator fan not coming on,after new 180 thermostat-temp gauge 206

[ski.dive]

I put a new 180 thermostat on yesterday.

I turned the Reatta on, and the temp. gauge got up to 206 and the radiator cooling fan did NOT turn on?

 

Fan used to come on at 196-197 before?

 

The temp at the radiator was also 206 with my laser temp gauge

What do I need to check?

[Ronnie]

Keep in mind that the thermostat does not control the upper temperature the engine will reach. It limits how cool the engine will run at highway speeds and in cold weather.

 

Also, the thermostat has no control over the fans. The fans are controlled by the ECM computer. The ECM is programmed to turn on one fan when the A/C is turned on. The other fan should turn on when the temperature reaches about 230 degrees. You can test the operation of the fans using the "overrides" in diagnostics as described in the diagnostics instruction booklet. Get to know the diagnostics booklet well. It is your best friend when troubleshooting your Reatta.

 

The ECM can be reprogrammed to turn on the fans sooner to make the engine run cooler. There are also a couple of tricks that can be done to override the ECM to make the fans run on high all the time.

[ski.dive]

Ronnie,

 

I just read a post of yours, where you put a Jumper on a 1988,to make the fan run on High when the A/C is on.

 

Question:

Do I splice on the red/blk wire with a white wire and screw the white wire to the phillips screw on the resistor that has the black wire?

Is it easy to get to this resistor on the 1988, where is it?

[Ronnie]

Let me take a look at the wiring and I will get back to you on how the jumper wire connects. The resistor can be seen on the drivers side of the radiator inside the engine compartment. It is pretty easy to get access to it.

[Ronnie]

Question:

Do I splice on the red/blk wire with a white wire and screw the white wire to the phillips screw on the resistor that has the black wire?

Yes. I crimped a connector on the jumper wire (color doesn't matter) so I could attach it to the screw and connected the other end to the red/black wire as show in the photo below. It helps the engine cool much better when sitting in traffic wit the A/C turned on.

 

This modification only effects one fan. The Reatta has two fans. One on the rear of the radiator and one on the front the radiator. The other fan will turn on when the engine temp gets really high to cool the engine back down.

[ski.dive]

Yes. I crimped a connector on the jumper wire (color doesn't matter) so I could attach it to the screw and connected the other end to the red/black wire as show in the photo below. It helps the engine cool much better when sitting in traffic wit the A/C turned on.

 

This modification only effects one fan. The Reatta has two fans. One on the rear of the radiator and one on the front the radiator. The other fan will turn on when the engine temp gets really high to cool the engine back down.

Is there a way to turn on both fans at the same time to come On, when I turn on the ignition key?

 

Have Both fans on all the time when I drive?

[Ronnie]

It is probably possible but I don't know anyone who has done it on the '88 models. They are wired differently from later models that do not use the resistor we have been discussing.

 

A jumper can be made for later models to run the fans all the time but I don't know how to do that. I don't think the jumper they use would apply to your '88 model.