New2Chevy

iTrader: (11)

I changed my radiator, thermostat, and fan switch, and my electric fan still won't come on, and the temperature gauge goes up to almost the red line. I checked the relay...it's good. I hot wired the fan motor...it's good. I changed the fan switch, and I thought that would fix it. The fan still refuses to come on. I cleaned all the electrical connections with electrical cleaner spray, and I double checked the relay with a nine volt battery, and it works, and the fan turned beautifully when I hot wired it. I saw the fan come on last Saturday, when I bought the car, but it hasn't come on since. I am totally stumped. Any help would be appreciated guys! This is driving me crazy.

New2Chevy

iTrader: (11)

I'll have to take the car in to a professional, so he can pinpoint whatever electrical problem there is. The dang fan just won't come on.

deadbird

Did you check the 'FP FAN' fuse (20A) under the dash ?

Keep in mind the ECM set temp is 220°F and the fan switch is 238°F and the gauge, over time, isn't 100% accurate.

New2Chevy

iTrader: (11)

The fan came one once when I turned the a/c on, but it won't come on when the gauge reads higher temperatures. I did not check the fuse under the dash....couldn't see that fuse under there. I'll check again. Thanks for your reply.

deadbird

Are you sure you changed the fan switch ?
AFIK, the 86 TPI didn't have one (which would be redundant, like the v6 had in certain years) for the single fan.

New2Chevy

iTrader: (11)

I discovered that I actually changed the knock sensor out and put a fan switch in there instead....a mistake I cannot believe I made. Yeah, I cannot find a fan switch anywhere on the engine. I've searched and searched....but all the auto parts stores pull up part numbers for one....it's weird.

New2Chevy

iTrader: (11)

I'm about to just install a manual switch to turn the b**** on. My engine is getting way too hot.

racethesunlive

don't forget about the aftermarket relay setup I had mentioned in the other thread. It really is the easiest way... how do I know? I went through exactly what you're going through now, replacing every sensor and tracing every wire just to have the fan still not kick on.

88TATBI5.7

I have had the connector to the relay burn out make sure its making a good connection

New2Chevy

iTrader: (11)

Thanks guys. I just found out, too, that my fan switch is actually on the front of the intake manifold. No wonder I couldn't find it on the side of the engine.

New2Chevy

iTrader: (11)

What other thread was this? That sounds cool.

deadbird

That is not the location for a fan switch, unless it was relocated there by a previous owner.

Refer to this post if you want a visual of where the fan switch should be...

https://www.thirdgen.org/forums/cool...r-heating.html

Again, I don't think your particular year/fan had a switch and was strictly ECM controlled.But, I can't say I'm 100% right either. Just going by diagrams.

New2Chevy

iTrader: (11)

It is, in fact, controlled by the ECM.

zraffz

Just wire the fan to a wire from the head unit that reads when ignition is turned forward, your fan will always be on when the key is turned on a take longer to cycle upon start up but it's an easy way to fix the problem.

racethesunlive

You can just wire this relay up from the battery to the fan. It'll turn the fan on at 185* and you dont have to worry about the chevy sensors or ECM. plus... its cheap at only $25. Tested and proven working on my 92 camaro

http://www.autozone.com/autozone/cat...mpressor+Works

Just push the sensor inbetween the radiator fan fins so the relay knows when to kick on.

New2Chevy

iTrader: (11)

Ha, cool. I'll look into that for sure. I'm also changing to an aluminum high output water pump.

reapper_1989

The fan switch is located in between cylinder 6 and 8. it is right up against the oil dip stick. I have changed it in 2 of my camaros. it always works after replacing it (just lucky that the rest of the circuit is complete).it is were the starter is at.

CaliChevyLover

dont ghetto rig anything to the radio or somethin like that

u dont want ur fan on all the time, running too cold can cause problems

put ur knock sensor back in, and replace the coolant temp sensor that is on the front of the intake manifold.

boldguy

I hereby second that


there are 3 sensors that have to do with coolant on cars that have dual fans.
1) The coolant Temp sensor on the front of the intake manifold, tells the comp how warm the car is and where to put the IAC and the SA/fueling etc.
2) The coolant temp sender(sometimes water temp switch), on the driver side cyl head between #'s 1 and 3. Sends a signal to your cluster to tell YOU how warm the coolant is.
3) The secondary cooling fan switch, on the passenger side block near the knock sensor in between #'s 4 and 6. Tells the computer to tell the relay to turn the fan on.

New2Chevy

iTrader: (11)

I heard that, since my car is an 86, the fan turn-on is controlled by the ecm. I have found no switch on the block. I am going to change the temp sensor on the manifold, since it is old. I am also installing an aluminum Weiand high output water pump. I also am going to install that aforementioned standalone Torqflo fan relay/switch setup from Autozone, the one that is programmed to turn on at 185 then off at 170. Unfortunately, I need to yank out the a/c condenser, so I can put the pin through the radiator fins and put that clip on the end of it, to hold the darn thing in. I yanked the smog crap and all a/c stuff off the car anyway (I don't need EITHER here in beautiful Wyoming), so here's my chance to get rid of the condenser, too. With the new water pump and the new fan switch, my car should definitely stay nice and cool.

New2Chevy

iTrader: (11)

By the way, I picked up the box that had all my a/c and smog stuff in it, and that frickin' thing was pretty heavy. I think I shaved at least 40 pounds off the weight of my car. Can't hurt.

deadbird

Minor corrections,

2) Not a sensor. Not a switch, unless you have an idiot light only (older models).

3) Not a sensor. Between #6 & 8 exhaust ports (it wont fit between 4 & 6)in the head. It's just an on/off switch independent of the ECM. Used to control secondary fan TPI. Primary fan control TBI, Redundant fan control for v6, seemingly just the 2.8 years.

None are exclusive to dual fan cars.

New2Chevy

iTrader: (11)

THanks for all the posts, guys.