Hi,
I have a 1990 Firebird with 305 TBI engine,it is all stock.

I was wondering what the stock temperature is at which the fan switch turns on the fan?
Right now the car will reach about 220 degrees at idle even though its only 77-80 degrees out and I'd like to get it running cooler.
On the freeway it runs about 190-200.

Would I be able to change to a 180degree thermostat and a lower temp fan switch that turns on sooner? or should I keep the stock thermostat and get a lower temp fan switch that turns on sooner?

My fan doesn't seem to come on until the gauge is in the 220 range.

Any advice would be appreciated.

By the way my Firebird has the single large fan.

 

At the tone, leave a message and I'll get back to ya. yeah, 180 thermostat is good combined with a little lower fan turn on temp. Do a search on this forum and turn up TONS of good advice on the subject

 

Thanks "Henryd3"
.....you weren't the guy who kept leaving messages about those three African goats for sale on my answering machine were you?

 

right around 238*

 

Your car sounds like it is pretty much performing flawlessly the way it was designed to. Changes you may wish to make depend on your preferences and the prevailing climate where you are. Happy deciding!

 

I think cooling fan temp is lower on the single fan TBI car, like 220. Dual fan cars the fan switch runs the secondary fan, and thus is set at the238 temp since it's onlyu controlling the secondary fan and the ECM should turn on the primary fan before that temp is reached. There are lower temp switches available - do a search for a thread titled something like "Alternative Fan Switches" or Fan Switch Alternatives", and you find a thread that lists part numbers and temps for several diffrerent switches.

Swapping to a 180* stat is fine, but no lower - any colder and you'll run rich since the car never gets warm enough to properly run (according to the ECM anyway).

 

i was going off the spec from the stock switch that i put in mine. i have a 92rs tbi.220 is where it ran and right at 230 to 238 it would turn the fan on.

 

my car is doing the same thing i dont ever rememeber it waiting so long for the fan to kick on, i wll be driving it and it will get up to 220 and the fan still wouldnt have turned on. my never usually ever goes past 200

 

Are the 185 switches from tpiparts good?

 

Hey Henry,

I've been searching through this forum for awhile and I haven't found my exact issue yet. Probably digging through things for a few weeks on and off.

91 RS 305 TBI Stock.

What if the fan doesn't turn on period? I have a single fan car, i've checked the relay, and replaced the thermostat with a new 195. I ordered that JET switch 60600 but they appear to back ordered. Hell, it won't even come on if i flip the AC vent on, which works, which is supposed to force the fan on.

*Interior temp gauge appears to be working, I let it go ALL the way up and still no fan.
*Tried running it with AC vent on, nothing
*tried a voltmeter at the weather proof connector for the fan motor and ran the above two tests again to check for power, nothing.

Best I can figure, It's the switch, but I'm new to Camaros. Later this evening I'm going to try to give the fan motor 12V and make sure the fan motor itself isn't toast.

Any other ideas are very welcome at this point. I'm not to the stage yet where I'm picky about how hot the car runs, I just need the coolant not to start boiling on a 20 minute trip.

 

First put 12 volts to the fan and make sure it works.. If it does, ground the green with white stripe wire going to the relay with the key on. If that doesnt work or if turning to AC with the key on the relay sounds bad. Unplug it and look at the contacts for burn areas. The fan switch just grounds out that green with white stripe wire. if the fan goes on when you ground it then your relay is good and the fan switch is the problem or the wiring between it and the relay is bad. only three parts to this system. It's either one of them or the wiring in between
Happy hunting

 

Thanks henryd3!

I put 12V to the fan and the fan works. I then grounded the green with white stripes wire going to the relay and put the key on. I'm still not getting any action out of the fan regardless of AC settings. The car was sitting for awhile, I'd bet there is a damaged wire in the circuit that I haven't found. As you said, there are only three parts to the system. I must be missing something simple..

Thanks

 

So when you grounded the green and white wire with the key on did the fan go on or not? If it doesn't that doesn't, that points to a bad relay unless the relay is working and the power is just not getting to the fan. See if the relay is working when that wire is grounded with the key on. It should be sending 12 volts back down that thick black with red stripe wire if it's working

 

Yeah so I grounded the green and white wire with the key on and the fan did NOT go on. It acted the same as it always does. I'm sure the relay is fine because I swapped it with the fuel relay and the fuel pump was audible when I turn the key on.

I think the power is not getting to the fan. I will also test the relay your way and make sure it's sending 12 volts down the black with red stripes wire.

 

And besides that wire sending 12 volts, you also need to make sure the other wire to the fan is actually grounded properly. Just another thought. And check the fan plug as well

 

Alright, so I think I am making some progress based on your suggestions.

Today, I tried to tackle it and double check all my work from before. I again, just to eliminate myself from the suspects list, gave the fan 12 V directly to the motor. The fan powers on and is stable.

Fan=check

I then ran a continuity test from the black with red stripes wire between the plug (relay side) and the plug (fan side) and confirmed continuity.

Black with red stripes wire= check

It's seeming more and more like an issue with the ground side now. Given, i've confirmed continuity on the power side.

My last test, even as redundant as it seems at this point, was that I have the green and white from the relay grounded, key in the on position, AC both on and off, and no action on the fan. I can send pictures if it will help. I'm either really close to a solution or nowhere near one.

Thanks again for all of your help,

 

Yeah, but do you get 12 volts on that wire at the fan plug when you test it? If so the only thing left is the ground not being good

 

I get nothing at the fan plug when I test it, which is what has me really confused, and I'm questioning the relay again.

 

That would seem to indicate either a bad relay or a fault in the the connections at the pigtail the relay plugs into. Relay has four wires going to it. Big orange one has to have a constant 12 volts going to it. The little tan or grey wire should get 12 volts with the key on. When the green with white stripe wire is grounded that trips the relay and makes it send 12 volts down the Black with red stripe wire to the fan. If the negative side of the fan is grounded the fan will now work That's all there is. which one of those things is not happening?

 

AH!

Got it!

It was in the ground loop up near the relay. plain black wire was damaged on the underside and cut through. I had to do a quick wire repair and oila!

Now I wonder if I never had an issue with my switch in the first place!

Thanks again for your help!

 

Cool, glad you found it

 

have you changed the fan motor itself? In my car i replaced the fan motor twice in 10 years and the relay once,, the termostat twice.. i don't know what happened but my fan stays on all the time. Doesn't cut off anf my gauge stays at 180-190 all the time unless I really push on the gas and go hard on the engine then it will go upto around 200-210 and then back down after about 20 minutes. Also I flushed the coolant and always use some kind of additive like purple ice

 

So, does your fan turn on as soon as you turn the key to on without starting the car? If your AC/heater control is not on off, but on AC or defrost that will turn on the fan also. If the fan runs with key on/ engine off, try moving your AC control and see if it goes off