camarosource

iTrader: (1)

I've diagnosed the left relay under my hood is ticking Very Loudly... Never heard this before, I thought it was my dash rattling like mad until I popped my hood and discovered it was one of my 2 relays on the firewall.

There are 2 relays on the driver side of the firewall where the brake booster is.. It's the LEFT one..

What relay is this? Why would it be ticking really loud?? On it's way out?

Thanks

BigBadLou

iTrader: (3)

"The left one" doesn't tell us anything because we cannot see your car.
What wire colors does the relay have? (that'll tell us what it's for)
Surprisingly, a stock '92 Z28 normally has 3 relays in that location. Two for fans and one for the fuel pump.

If it's the fan relay, you should probably see one of the fans spinning slowly. If it was the fuel pump relay, you'd have fuel pressure issues, I'd think.

Wire colors will help us determine which one it is.
Lou

camarosource

iTrader: (1)

Ok. Appears they have the same exact writing on the top of the relays.. It's the far left one.. They all seem to have the same color and thickness of wires going to them EXCEPT the one that is on the left that is chattering is the ONLY ONE THAT DOES NOT HAVE A GREEN WIRE GOING TO IT..

ringo234

Replace it they're cheap or switch the two relays (they should be the type) and see if the clicking changes with the relay. That way you'll know if it'd the relay or the circuit itself.

camarosource

iTrader: (1)

But How do I know what relay it is ;-) No one told me if it's fan or fuel pump..

Also, how do you remove it? Looked like there was a plug perhaps on the bottom (really tight so it's hard to see under it) but there was a clip on the side with a white tab that looks to be a tab to prevent you from opening. Appeared you had to break it to get it out... ?

camarosource

iTrader: (1)

Now I'm really confused!

According to this: https://www.thirdgen.org/forums/elec...ump-relay.html

That left one is a "Electronic Spark Control (ESC) Module" (Course that person is referring to a TBI, I have a TPI) Not sure if that matters in this case or not.

camarosource

iTrader: (1)

The number on the top of it has:

1344
14103304


E ------ C
|
------A
D [Ohms code] F

BigBadLou

iTrader: (3)

Ringo is right, you can swap the relays. THey're identical so there's no harm. That will tell you if it's the relay or wiring.

Your car does not have the external ESC module, it's all inside the distributor. So you should only see relays by the brake booster.

The relay has a tab and needs to be lifted gently and then connector comes out downward. If the tab has a lock through it, squeeze it with needlenose pliers or another suitable tool and pull the lock out first.

You say that the relay does not have a green wire. That would point to the auxiliary cooling fan relay.

What happened just prior to the relay clicking? A/C trouble? Overheating? Fan trouble?
Also, is the relay clicking fast? Consistently? Or does it change speed? Does either fan turn when the relay clicks?

Lou

camarosource

iTrader: (1)

Appears to NOT be the relay! And just wasted $20.

I got a new relay. Replaced it and it's still chattering.. However I have more information on WHEN it chatters.. Seems to have a particular occurance mostly.

It Chatters the MOMENT you put the BRAKE PEDAL where the brakes start to engage and your brake light comes on. If you put it on PARK with your foot OFF or ON the brake it will chatter. The moment you take it out of park, or take your foot OFF the brake pedal it stops but MAY VERY SLIGHTLY chatter off and on while driving..

I don't see any overheating problems. My AC seems to be working.. If you touch the one relay, you can CLEARLY FEEL the thing chattering away inside it..

camarosource

iTrader: (1)

Ok.. well turns out I was wrong!

Looked under the hood and I can clearly see the PRIMARY (Passenger) fan TRYING to turn.. like it is almost getting voltage for 1000th of a sec as it moves like 1degree and keeps doing it off and on..

Once I got to temp the secondary turns off PERFECTLY FINE.. Spinning away as it should while the primary is still trying to even make 1 turn!

I do have it on video..

The relay that is chattering has the following wires:

Orange
Black with purple stripe
Brown
White or Tan colored.

The other two relays have the same colors exactly they both have a green wire where as this relay does not.

camarosource

iTrader: (1)

http://s17.photobucket.com/albums/b5...t=100_2653.flv

BigBadLou

iTrader: (3)

My educated guess is that the white or tan colored wire is either rubbing on ground somewhere or even worse, you have a bad-ground problem and the brake circuit is influencing your auxiliary fan circuit, actuating the relay repeatedly.

The tan or white wire (should be actually grey) is controlled by three elements: the A/C pressure switch, the ECM and the overheat switch (in the passenger head). Any of these could be causing the spikes to the relay and the clicking.
Diagram here.

You can disconnect the passenger head overheat sensor, you can disconnect the A/C pressure switch but it's not easy to disconnect the ECM pin. Well actually, you can just pull the whole ECM out. If the chattering goes away, it was the ECM.

Let us know what you find! This is a puzzling problem and I'm very interested in knowing what caused it.
Lou

camarosource

iTrader: (1)

Could it not be possible that the fan is just dieing??

BigBadLou

iTrader: (3)

Not easily. The fan is controlled BY the relay, not the other way around. So if the fan is spinning, the relay is making it spin. But something is making the relay chatter. From the diagram in my previous post, you can see that the relay is actuated by one of the three sources that I named. Either one of these sources is faulty or the wiring has a short to ground somewhere, causing the relay chatter.

By answering our questions, you can help us help you determine what is possibly causing this.
By performing the tests we recommend, you can find the problem even faster by yourself.
The fate of your car is in your hands, my friend. (now doesn't that feel good?! )

Lou

camarosource

iTrader: (1)

I've taken the car to 3 mechanics now and no one can find it! It only chatters when people are NOT around.. Only for me!! And when I take it there and the 2 times it did chatter for them, they wiggled wires all over and nothing seemed to do anything to point what was causing it and it then stopped and of course they have nothing to go on..

HELP!!

I spent an HOUR in the cold when it was REALLY chattering like crazy, wiggling wires under the hood trying to find out what was causing it. All I did it just waste gas and didn't accomplish anything. Pressing the gas didn't do anything to it, seems to be effected MOSTLY by the brake pedal or putting into park. Doesn't seem to have anything to do with temperature nor idle speed, nor AC settings, nor engine speed..

I did notice today that when it stopped, all it seemed that I needed to do was get in the car, close the door, drive like 20 feet and then stop and the chattering would come back.. the relay would then chatter like crazy and with a flashlight on the passenger (primary?) fan, the fan would be flicking on and off before it can even make any time of rotation.. Like it was having a seizure

NINÅ

That IS the primary fan relay.

Because the brake pedal affects it, it sees like wire insulation has rubbed thru somewhere.

To find out why it’s chattering:

Disconnect the output side of the relay and see if the problem continues.

If it does NOT check for a bad fan or short in that line.

Test your fan by disconnecting the connector at the fan and applying 12 volts to it.