Last year when I bought my 88 Formula I noticed that neither fan would come one and the car would start to overheat so I wired up some switches to activate the relays for the fans till I could troubleshoot the cause of the fans not coming on. Well, a year and a half passed by and I never looked for the problem since I just ran the primary fan all the time.

Two weekends ago I swapped my 700R4 for a T5 and drove around with the Auto memcal in the car till yesterday when I decided to program a new chip for the T5.
So I burned a chip, pulled the stock memcal and attached it to the adaptor, put it all in the ECM and started the car.

So I switched off my fan and started the car so that it would get up to operating temp faster and I am sitting there watching the temp gauge and it stops at 160 and won't go any higher so I hold the rpms at 2K for a bit trying to get the car warmer and it still sits at 160. At that point I am thinking that my temp gauge got stuck since I have my fan off, so I switch the fan on and I don't notice any difference in sound.
I then Turn the switch off and get out of the car and look in the engine bay and my fan is working on it's own.

The program I am using in the car is the 89 ARAP bin set for a T5 with the fans on/off temps lowered for my 160stat. Even though I had the fans wired up for manual operation, it's just a habit to lower the temps in the programming.

 

My brother had his wired manually for a couple of years because he said, "it overheats if I don't." Then, I showed him that they, (well, it) actually worked normally if he would wait for the temperature to come up to 228°. Yep, factory programming was 228° on, 218° off.

It ran better that way too and he didn't understand that. I personally like about 186° on and , 178°off.

 

My car was hitting 260, which is really really hot. 220 is where it sits normally if everything is working and I don't really like it that hot, better for emissions but a little hot for performance.

 

This was in a TPI in a GMC truck and it actually wasn't getting that high. Verified with a scanner the fans were working normally. It sure looked too high compared to the 305 with a belt driven fan he took out though.