1.8ttolt1

I have a 94 Z28 and overheat when ever I come to a stop for a prolonged period of time. I found that the fans are not coming on.

I replaced the underhood fan fuse which was blown, but the fans still do not come on.

I then pulled my foglight relay and substituted it for the fan relays to see if that would solve it. No luck.

In addition I replaced the engine temp. sensor in the water pump.

I then jumped the fans with the DLC. A humming sound comes from the front drivers side of the engine but to be honest I can't tell if its coming from near the fuse box (relays) or if it's the fan motor.

Even though I have a 94 it is a late model and has the three fan relay, not the two. I'd like to avoid buying more parts I don't need if I can figure out what the problem is.

What I need to know is, what are the symptoms of a bad fan motor? What are the symptoms of a bad relay? Are there any more tests I can do to isolate this problem?

This also occured at about the same time my car spazzed out one day and the rpm gauge would flutter and the car would die regardless of throttle input. It was also impossible to get into reverse (m6). Later that day the car drove fine and reverse is accessible but is still more difficult than it used to be to get into. Thought I'd add this because I don't know if it's related or not.

Thanks for the help. I really, really appreciate it.

LT1553

I know this reply is going to be of no help but i just wanted u to know that i am in the same boat as u engine will get so close to red before the fans kick on, it annoying and frustrating, i changed the coolant temp sensor as well and that didnt do anything either. Best way to test ur fan motors is to pull the fans out of the car and put 12 volts to them with a battery charger or something and if they work then obviously they will begin to turn. Im stuck on this one as well and dont know how or where to begin to look to fix this mess. good luck to ya anyways

Heath

DonHood

The stock fan kick-on temperature on our cars is set scary high. Sitting at redlights on hot summer days, I'd watch in horror as the needle kept inching closer and closer to the red. It seemed that the fans would wait to kick on till the engine was about to warp a head, or melt to the ground. I got my Scanmaster and monitored the temps, and it showed that the fans were coming on at exactly the right times, but on my dash gauge it looked a lot worse.

I got Madwolf to re-program the fans to cut on at 200, and now it never gets above 202-203, even when idling in 90* weather.

1.8ttolt1

My computer is programmed for the fans. The problem is that they don't come on at all. I think I'll try pulling the fans out to see where the noise is coming from. I don't know what else to do.

shoebox

Get the car up in the air, like on ramps. Unplug the driver's side fan and see if you hear the same noise when the DLC is jumped.

blue

My dad told me that a guy he works with said one of the circuit boards on the cars has several connections that break. He said you can look at the board under a magnifying glass and see where the soldering has come apart. The wipers on my 94Z will sit about 15 degrees higher than they should when I turn them off, so I have to push them down manually. And then once in a while, out of the blue they will set down while I'm driving, even if they haven't been on. I don't know if the circuit for the fan runs through this board, or even where the board is, but this could possibly be responsible for the problem.
I will ask my Dad about it again and maybe one day take the board out and do some soldering.

enzo1267

same problem here with the wipers....thought it was time for a new wiper motor.

shoebox

Wipers have nothing to do with the PCM.