I think I have my problem figured out but I want to get a second opinion.

the previous owner of my 1990 had a shop do an electric fan conversion about two years ago and replaced the radiator with a three row aluminum unit. I'm not a huge fan of the conversion that was done, they removed the fan cowl and just attached a radiator fan in its place. As a result I have a large area that is not getting Air actively sucked through it. the kit came with its own temperature sensor that is attached to the radiator itself.

on the highway I can't get it to heat up to more than about 180°with a trailer. in town it likes to hang around 210°.

Fast forward to yesterday day it has finally warmed up and hit about 80°. the highway performance is just the same but, It's overheating (from a cold start) after idling between seven and 10 min. but if I turn on my air-conditioning it will sit at 210 to 218 for as long as I'll let it. I assume this means my coolant temperature sensor on the block is on its way out or the ECU is dying. Any other ideas?

I am moving in six days so don't have a lot of time to think or trial and error, otherwise I would not even ask.

please let me know if you think I'm on the right track, wrong track or off the tracks.

 

Do u have efans only? Positive it has a t-stat? Fan comes on with a/c? How much above 218 does it go? Verified temp with infrared temp gun?

 

thanks

 

I'm no expert but I think it would make more sense to at least have the aux fan wired to the stock efan and have the stock fan wired to its original location. Doing that would have the fans come on at the proper temp.
You will definitely want to to get an actual operating temp.

 

I would do that but I don't want to turn my wiring harness into a rats nest of splices and the like.

I have heard of people running 2 aux fans, are there any write ups on the subject?