*This coolant fan modification may only work on the '88 models. Other models may be wired differently.
*This modification is suggested for only those individuals who have knowledge of reading electrical schematics and the proper tools to perform the work.

I installed the Hayden fan control relay kit (#3652) on my 1988 model Reatta. Everything went as expected. All wire connections were made underneath the fuse/relay block that is located under the hood. The relay fit inside the fuse/relay box. However, I did run into a problem. The probe that came with the Hayden kit when inserted into the radiator would not sense the temperature properly. The fan would not come on until the temperature was past 210°. That was too high.

To correct the problem I drilled and tapped, (6-32 tap), the center of the bolt that holds the thermostat housing in place and screwed the thermal snap switch, that came with the kit, into the head of the bolt. Now the fans turn on at 191° and turn off at 176°.

I'm happy with the outcome but looking back I would spend the extra $ 10.00 to purchase the adjustable model of the fan control relay. That might allow the probe to work in the radiator as intended.

Probably the better way to go is to get someone to modify the PROM if you can get someone to do it. But, sometimes there is a little satisfaction to know you did it yourself the hard way.