RELAY (Fuel Pump) is chattering...
11-11-2008, 01:57 AM
#1
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RELAY (AC) is chattering...
Here is an interesting dilema.. I keep hearing a VERY loud chatter where what I believed was inside the dash. This only started happening approx 1 week ago. Seems to be getting louder each day so I parked the car and went to investigate. Discovered it's my AC RELAY chatting like crazy.. As if there is a morse code device inside it!
I get a new AC relay from the dealer, install it. Still chattering..
However there seems to be a particular time when it does the worst. Seems that the MOMENT you apply the brakes (so far that the moment the brakes start to engage and your brake lights come on) the the chattering occurs like crazy. The MOMENT to take your foot off the gas it stops! Put the car in PARK (either WITH or WITHOUT my pushing on the brakes) and the chattering occurs. Take it out of park and it stops..
I can be driving and it MAY SLIGHTLY on occasion chatter but barely noticeable.. But the moment I put the brake down to engage the brakes the chattering happens. It's nothing to do with vibrations.. Seems the engaging of the brakes is one of the symptoms..
1992 Camaro Z28 TPI L98 350
I get a new AC relay from the dealer, install it. Still chattering..
However there seems to be a particular time when it does the worst. Seems that the MOMENT you apply the brakes (so far that the moment the brakes start to engage and your brake lights come on) the the chattering occurs like crazy. The MOMENT to take your foot off the gas it stops! Put the car in PARK (either WITH or WITHOUT my pushing on the brakes) and the chattering occurs. Take it out of park and it stops..
I can be driving and it MAY SLIGHTLY on occasion chatter but barely noticeable.. But the moment I put the brake down to engage the brakes the chattering happens. It's nothing to do with vibrations.. Seems the engaging of the brakes is one of the symptoms..
1992 Camaro Z28 TPI L98 350
Last edited by camarosource; 11-25-2008 at 02:25 AM.
11-11-2008, 02:15 AM
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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.
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.
11-11-2008, 02:42 AM
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11-11-2008, 08:03 AM
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pretty simple man. You need a new Fan. the reason the relay is going off on you is because the fan motor is shorting, which will cause it to pop the relay, and it will just keep doing that forever until the relay dies. (same issue with a set of lights and a short and an electric fan and a short) Replace you fan, and I bet that fixes your issue.
11-11-2008, 12:36 PM
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pretty simple man. You need a new Fan. the reason the relay is going off on you is because the fan motor is shorting, which will cause it to pop the relay, and it will just keep doing that forever until the relay dies. (same issue with a set of lights and a short and an electric fan and a short) Replace you fan, and I bet that fixes your issue.
I would SURE hope that is all it is.. Just replacing the fan motor.. But this reply from another site has got me worried..
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
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
11-11-2008, 09:37 PM
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I would replace the fan and trace the harness, or trace the harness from the fine to the relay... it is either a wire grounding (shielding rubbed off and it is shorting) or the fan motor itself is dead. All that is happening is the relay overheats instantly due to the short. Start from the fan and go upstream.
11-11-2008, 09:40 PM
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I would replace the fan and trace the harness, or trace the harness from the fine to the relay... it is either a wire grounding (shielding rubbed off and it is shorting) or the fan motor itself is dead. All that is happening is the relay overheats instantly due to the short. Start from the fan and go upstream.
11-11-2008, 09:53 PM
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11-11-2008, 10:05 PM
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Sunday I should be able to see what's going on tho
11-11-2008, 10:30 PM
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you could try to remove brake light fuse and see if it still does it if it does unplug the brake light switch at the pedal to see if it is an electrical issue or mechanical issue from pushing pedal also unplug the fan thats not working hopefully one of these will bring you closer to resolve
11-11-2008, 10:49 PM
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you could try to remove brake light fuse and see if it still does it if it does unplug the brake light switch at the pedal to see if it is an electrical issue or mechanical issue from pushing pedal also unplug the fan thats not working hopefully one of these will bring you closer to resolve
Got 3 fuses to choose between it seems..
"Taillights" 20amps
"Parking lamps"
"Stoplight switch"
11-12-2008, 08:20 AM
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you can go over to the thirdgen forum for a schematic or e-mail willie .. see http://www.thirdgen.org/techboard/co...n-control.html . Once you have a good schematic you can verify grounds and voltages, jumper around the relay pick, the entire relay, swap relays or fans to isolate the problem. Sorry, I only have 4th gen schematics, no help to you.
11-25-2008, 02:26 AM
#13
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pretty simple man. You need a new Fan. the reason the relay is going off on you is because the fan motor is shorting, which will cause it to pop the relay, and it will just keep doing that forever until the relay dies. (same issue with a set of lights and a short and an electric fan and a short) Replace you fan, and I bet that fixes your issue.
11-25-2008, 02:27 AM
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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
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
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