My 1985 IROC has TPI and like most all of these cars have aproblem with high temps while sitting. My fan kicks on at like 220 degrees. I wanted it to kick on sooner so I thought I'd just go out & get a low temp sender for it. Well turns out I can't find it. It is not on the passenger side cylinder head and the one on the driver side controls the gauge. SO my question is that on model year 1985 was the fan computer controlled? If so do I need a chip get the fan to come on sooner? If so can I just buy one from JET or Hypertech or will I have to burn a custom chip? Any help is appreciatted.

 

Need to buy a fan switch and install it in the pass.side head. You have to remove the plug in the head between #6 and # 8 cylinders. part.http://store.summitracing.com/partde...5&autoview=sku

 

I have a fan switch already, but I could not find anyplace to put it. There is not one in my passenger side head. Is there anywhere else this may be found? Also checked my service maual and it has no mention of such a switchon the TPI engine. The wiring daigram does not show such a switch. Or is there a plug in the head I have to remove, install the switch then wire it in? There is no harness or anything for it. I am at a total loss here. The switch I have is the hypertech version of the one in the link above. On the box it says it fits '83-86 camaro 305 HO; 86-87 camaro 305 LG4; 88-92 camarao 305 TBI; 86-92 camaro 305 TPI with dual fans ; 87-92 350 TPI with dual fans, 84-90 corvette CF/TPI with dual fans. Mine has a single fan and is a 1985 with TPI which is not listed. I have the hyptertech cool fan switch #4026. I do not know much about the TPI engines as I am fairly new to them. Please help a noobie.

 

maybe it uses the coolant temp sensor on the front of the intake manifold? Sorry i don't know much about that year. I wish I could help more. Good Luck

 

Your model appears to provide a ground to the coolant fan relay through the ECM. You can add the temp switch to provide a control ground in addition to the ECM provided control by either tapping into the AC switch (before ECM) or the relay control ground. Probably would be easier and safer to tie into the relay control lead, leaving all other wiring in place. This would let the AC switch still engage the fan.

There is a plug in the head in the exact same spot as the temp switch on the driver's side head-just with the head spun around to fit on the other side. It will probably have a square socket, just slightly smaller than a 3/8" socket drive. I have, in the past, ground down an old extension to pull one of these plugs.

 

 

thanks for the info guys. I have been searching all over for about a 10 days now. When the rain quits I'll crawl under there & replace that plug with my fan switch & see if I can wire it in withou burning anything up. Hopefully all goes well. Any other tips or info on this project or just these cars in general is greatly appreciatted. I'll post a pic when I get time too. Thanks again

 

Here are the instructions where you hook up the switch:


The temp sender on the driver side head will send the signal to your coolant temp gauge in your gauge cluster. There is a fan switch on the passenger side head on 87 and later models which turned the fan on. You can install the switch on your 85 by removing the blockoff plug from the passenger side head between cylinders 6 and 8, and installing the switch. You will need to run a single wire from the switch to the green/white wire at the fan relay. That will allow the fan to come on whenever the fan switch reaches the specified temp.

The plug in the pass.cyl.head is a PITA to get to. You will probably have better luck from underneath.

 

thanks for the wiring instructions badman. I thought thats how it would go , but had not had a chance to look at it since we've had steady rain here for the past couple days. Also I just noticed that I spelled IROC wrong in the title of my post. That makes me feel kinds dumb. Just out of curiosity what temp switch do most of you guys run in these cars? I have the 176 on 166 off switch but that may be too cold. I only drive the car in summer as it is stored in a capsule all winter so heat inside is not really needed. I use the car mainly to go to car shows and some weekend cruises. What would you guys recommend before I go about splicing this baby in? Thanks again for all the great posts

 

Just got it all wired up and installed. Everything works great. That plug was a pain to get out and I had to grind down a 3/8 extension to fit just like NAF said. My only thing is that I got the 176 on 166 off switch and the fan never shuts off now. I'll swap it out for the next heat range up and I think that'll do it. Thanks guys.