ZR180

I have a '08 ZO6 and the cooling fan does not work all the time when it should (temp 230 to 259). I've powered up the fan and it always runs. The fan control module has power and ground to it. How can I test the fan control module? How can I check to see if the computer is telling the module to come on? Someone told me it may be my coolant temp. sensor and that I have one just for the cooling fan. Is this correct? My DIC and temp. guage always show the engine temp. Sometimes the fan works fine, other times it doesn't and the car overheats. I would really appreciate any help! Thank you.

Unreal

Check the connector to see if it is melted/damaged. Very common.

Painrace

I had the ground corrode on mine. It is on the passenger's side.

Jim

VetteVinnie

Same thing happened to me. Total fan failure and the car almost overheated. Thankfully I saw the temps climb rapidly and was able to shut down the car before any damage was done. Now I have bypassed my fan connector and soldered the grounds directly together.

Here's the thread about it:

http://forums.corvetteforum.com/c6-t...d-working.html

94th hour

Just happened with my z over the weekend. Now I have another fun project for this upcoming weekend of re-wiring the fan .

SilveradoSS500

Yep, I just replaced my whole fan assembly, all melted!

Bill Dearborn

First, what do you mean by the car overheats? Do you get a warning on the DIC that it is overheating? Coolant temp will swing all over the place when sitting with the engine idling in hot weather. I have seen my C5s do it and my 08Z does it as well. As for testing the fan turn on the AC and it should come on and the temp should drop. I know from operating my car that running the AC on a hot day when the oil and coolant temps hit the mid 230s will bring them down to less than 220 in a matter of 10 minutes or so.

Bill

Bill

ZR180

Thanks guys. The forum is great. It was a burned spade connector as you suggested. Mine was the hot lead. It now cools great. It also fixed my AC which would quit working whenever the fans stoped.

glashoppah

Not sure what's going on with your Corvettes, Bill, but I've had three Z06es since 2003 which were (and are) my daily drivers, 200,000+ miles, and I've never had one with a temp gauge that wasn't nailed firmly at two major ticks before TDC when it was warmed up no matter what the weather or driving condition or how hard I was hitting it. I drive to Vegas regularly and am often in start-stop traffic on the 15 in 110+ degree heat, for hours, and my gauges never move a millimeter.

Until today, when the gauge swung to max and I got the warning "COOLANT OVER TEMP" on the DIC. Stopped and checked and yep, fan not running. Changed the obviously-not-blown fuse, fan still not running. Tomorrow I'll check the wiring.

H.

P.S. by the way, where do you get replacement power connectors? Looks like a very special part.

wstaab

http://www.casperselectronics.com/st...oducts_id=1003

glashoppah

It looks like they only have one half of the pair... any other likely sites?

H.

glashoppah

OK - so, my fan connector is pretty and relatively pristine, so this is not the problem. I disconnected it so that I could do some more troubleshooting. I note that there are three input wires, two heavy gauge wires which are RED and BLACK, which I will assume are the input DC power leads. The third is much lighter gauge and is GREEN, which could either be a fan speed sensor or some sort of control connection.

I applied 12v power from the battery to the RED and BLACK and the fan does not start. I note that there is a slight spark when I apply power - I am assuming I'm charging a motor start capacitor, because the spark only appears once. I can discharge it (with another slight spark) by shorting the fan power leads, and then it will spark again when I connect it. So again, it appears to have a motor start cap that appears to be properly storing a charge.

So I guess my conclusion is that the fan motor is bad, OR the green wire is an input signal that is required to start the fan. My question for the group is, should I see the fan start if the motor is good given only the application of 12V to the power leads, or does this motor require signal on the green wire as well?

H.

ZR180

[QUOTE=glashoppah;1581468253]OK - so, my fan connector is pretty and relatively pristine, so this is not the problem. I disconnected it so that I could do some more troubleshooting. I note that there are three input wires, two heavy gauge wires which are RED and BLACK, which I will assume are the input DC power leads. The third is much lighter gauge and is GREEN, which could either be a fan speed sensor or some sort of control connection.

I applied 12v power from the battery to the RED and BLACK and the fan does not start. I note that there is a slight spark when I apply power - I am assuming I'm charging a motor start capacitor, because the spark only appears once. I can discharge it (with another slight spark) by shorting the fan power leads, and then it will spark again when I connect it. So again, it appears to have a motor start cap that appears to be properly storing a charge.

So I guess my conclusion is that the fan motor is bad, OR the green wire is an input signal that is required to start the fan. My question for the group is, should I see the fan start if the motor is good given only the application of 12V to the power leads, or does this motor require signal on the green wire as well?


My fan would run when I powered the fan motor (Red / Black) as you did. That should run the fan if you are powering the motor leads. The small green wire comes from your computer to tell the fan control module when to run. There are a lot of conditions that will cause your fan to run.

I don't think that the fan motor is a capacitor start motor so the spark may mean your motor is bad. My problem was the hot spade was melted and lost connection. My car is tuned and if the tunner runs the fan too much the spade clips can't handle the power. I did, as many others have, just connected the two leads using 10 guage wire and left plenty extra in case I ever have to change the module. This fixed my problem.