ElementsofSpeed

i just want to know how it works and how hard it would be to replace on a 1991 trans am tpi 305ci. i have dual fans, so will it just kick on one of my fans or both? i am kind of confused on how it all works. I want my car to run at about 170 or 180...but 170 is better, right? i dont want to install a custom switch anymore because i am a dumba** and would forget to hit it. so, any ideas or suggestions?...I have read the tech and faq pages that others have made, just want a little more detail on my model of car and what would be best. thanks

ede

it replaces your factory fan temp senser, your fans will work the same as they do now, only the start temp would be altered

ElementsofSpeed

i see, so where is the fan switch located on my model car, and how much work is involved in replacing it with the hypertech? some pictures of where it is located would be great too if anyone could help me out in that section.

Matty377

It's in your passenger side head, between #6 & #8 plugs, just a little higher.

I don't have a picture right now, but it's a brass hex-shaped thing with a black plastic connector coming out of it.

It's not too much work. Unplug it. Drain your coolant, then take it out, put PST on the threads of the new one and put the new one in. Re-connect. Refill the coolant and you should be good to go. I'm not sure if you've got manifolds or headers though. It's really easy with headers, but manifolds might make it tricky.

ElementsofSpeed

i have manifolds...what tools do you think i will need, and did you say i need PST? whats that? plumbers tape? thanks a lot for your help. does that sensor only control the primary fan or both fans? thanks

Matty377

PST is high-temp thread sealant. Sort of like liquid teflon tape.

But PTFE tape won't work. You'll need the high temp liquid/gel stuff, not necessarily called PST (that's what Loctite called it), sorry about that.

Take a look and see if you can get the electrical connector off. If you can't get a deep socket in there, see if an open end or crowfoot wrench is able to get in there and get it off/on. If you can't get at it from the top, you can try getting under the car. The hex part is big so you might need larger than a 5/8 wrench for it. I think it was around 11/16 or 13/16, but it was a while ago so I can't really remember.

I've only got one fan on my camaro, so I don't know where the second fan is switched on from.

ElementsofSpeed

alright, i will try something to try to get it out. does the electrical connector just unplug like a harness or do you have to cut the wire and splice in the new one? i think it would be easier to go from underneath. also, which one do you recommend, and with which thermostat. I live in tulsa, OK, so do you think a 160 would be fine, or should i go with 180? my car just runs so much more smooth when it is running cool...its incredible. thanks a lot for your help matt

3.8TransAM

Go to a parts store and order a fan switch for a 86-87 turbo regal or 89 Turbo trans AM.

Same part they sell for $40 for about $15 :-)

Fans will come on about 205 vs. 235 stock

Watch running too low of a fan temp, contrary to what people say, many things are affected in the prom by too low of a coolant temp

later
Jeremy

Matty377

The connector is an oval shaped piece of plastic. Just squeeze the sides together and it should come right off. I think with the hypertech you may need to put their connector on the wire though, but 3.8's suggestion of the TTA/GNX switch will probably get you close where you want to be and save some $$.

As far as thermostats, they determine at what temperature to start circulating cooler fluid from your radiator into the engine and the hot fluid out into the radiator to cool. You don't want to go too low because you actually do want your engine to reach operating temperature before it starts to try to maintain a temperature. I think a 180 would be fine. 160 may be a little much, but I'm not sure. I'm not even sure what the factory one is, 196 or something?

ElementsofSpeed

i think stock is 192-196. hey 3.8, will that one for the buick regal or the TTA, it comes on at 205 and shuts off when? would it work with a 180? do you think hypertech would be more reliable though? i am trying to do this the right way...money isnt that much of an issue, quality is more important. what are you running right now matt? is it worth the money? thanks a lot.

Matty377

I'm running a 180 t-stat and just a stock replacement switch I got at autozone. Yeah, i guess that was all worth the $20 or so I paid for it.