1991 Audi 90 quattro 20V Electrical Problem
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1991 Audi 90 quattro 20V Electrical Problem
Hey everyone,
I have a problem where my driving lights/turn signals/hazard lights come on and stay on. I removed the fuse for the hazard lights, and they turned off, but when I try to use the turn signals, all 4 lights come on again rather than just the side that should come on for the turn signal. I was hoping to pull that fuse as a quick temporary fix since I could probably do without the hazards, but I still need the turn signals to work.
Basically, I think I have a short somewhere. I've had the problem before, and today when I started it, all was well. But then I took it to a car wash, where I'm sure some water got into something it shouldn't have, and the lights have been on ever since (I disconnect the battery to keep it from draining).
Does anyone know where the short might be? I kind of suspect a certain piece, but I'm not sure what it's called. It's a box next to the fuse box which is accessible under the hood partially under the windshield on the driver side. It is finned and has two cannon plugs on top of it. I suspect it as the culprit because the water would have an easy time of getting in there. It looked dry, but if water got in, it would take a while to come back out. I need to know what that piece is called, and it would be nice if someone could provide a wiring diagram or something for the car. I plan to look at a Chilton manual soon at the library, but if someone has the information, that would be helpful too!
Here are a couple of videos I made a few months ago when the problem began:
http://www.youtube.com/watch?v=W2DDFr01k3A
http://www.youtube.com/watch?v=vHShjzX1UwM
Here is a picture of the piece I was talking about. It's under the two cannon plugs toward the passenger side from the fuse box.
I have a problem where my driving lights/turn signals/hazard lights come on and stay on. I removed the fuse for the hazard lights, and they turned off, but when I try to use the turn signals, all 4 lights come on again rather than just the side that should come on for the turn signal. I was hoping to pull that fuse as a quick temporary fix since I could probably do without the hazards, but I still need the turn signals to work.
Basically, I think I have a short somewhere. I've had the problem before, and today when I started it, all was well. But then I took it to a car wash, where I'm sure some water got into something it shouldn't have, and the lights have been on ever since (I disconnect the battery to keep it from draining).
Does anyone know where the short might be? I kind of suspect a certain piece, but I'm not sure what it's called. It's a box next to the fuse box which is accessible under the hood partially under the windshield on the driver side. It is finned and has two cannon plugs on top of it. I suspect it as the culprit because the water would have an easy time of getting in there. It looked dry, but if water got in, it would take a while to come back out. I need to know what that piece is called, and it would be nice if someone could provide a wiring diagram or something for the car. I plan to look at a Chilton manual soon at the library, but if someone has the information, that would be helpful too!
Here are a couple of videos I made a few months ago when the problem began:
http://www.youtube.com/watch?v=W2DDFr01k3A
http://www.youtube.com/watch?v=vHShjzX1UwM
Here is a picture of the piece I was talking about. It's under the two cannon plugs toward the passenger side from the fuse box.
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I'm really not sure. When the lights aren't on, the turn signals and hazards work as you'd expect. The only thing that's amiss is that the right front turn signal sometimes doesn't work. And once or twice when the problem was happening, the left front turn signal wasn't illuminated, but the other three were. I disconnected and reconnected the battery, and all four lit up. And like I said, it seems like water gets into something and short circuits it, but I don't know what exactly. I suspected the thing under the hood next to the fuse box in the picture because it seems like a place where water would drain, and if something was cracked, the water could get in there and make a short.
#4
AudiWorld Senior Member
Re: "suspect box next to the fuse box"...
FYI sir, that finned box in your photo powers your engine's injectors, so even if defective, it may not be your issue. Is the lid and gasket for the fuse panel proper fully secure and water tight?
If the problem occurs after a trip through the car wash, perhaps some time spent with a simple garden hose with a spray gun attached may help you pin-point the location of the vulnerable components.
When the turn signals are working; and when the four-ways run by themselves, do they always flash at the same and proper speed? Do they cut in and out?
Another couple of checks that might be helpful is to see if:
- there is any corrosion on any of the bulb bases &/or receptacles;
- there is a constant drain on the battery with the key off;
- the chassis wiring to the turn signals has been altered/damaged (was a tow hitch ever put on the car?); &
- see if there is water &/or corrosion in any of the rear turn signal housing electrical spade connections.
If your ignition switch has not been replaced recently, perhaps it would be helpful to eliminate it as it is a common failure, and it is cheap and easy to do. Do a forum search here to find the particulars.
Other issues:
-The hydraulic reservoir has the green lid, close by to the driver's inner fender.
-The anti-lock brakes may have an on/off switch in the row of centre switches; and the switch may be broken. You can test the switch for continuity.
Get yourself a little owner's manual that would have come with the car; and check out 20v.org if you haven't seen it already.
If the problem occurs after a trip through the car wash, perhaps some time spent with a simple garden hose with a spray gun attached may help you pin-point the location of the vulnerable components.
When the turn signals are working; and when the four-ways run by themselves, do they always flash at the same and proper speed? Do they cut in and out?
Another couple of checks that might be helpful is to see if:
- there is any corrosion on any of the bulb bases &/or receptacles;
- there is a constant drain on the battery with the key off;
- the chassis wiring to the turn signals has been altered/damaged (was a tow hitch ever put on the car?); &
- see if there is water &/or corrosion in any of the rear turn signal housing electrical spade connections.
If your ignition switch has not been replaced recently, perhaps it would be helpful to eliminate it as it is a common failure, and it is cheap and easy to do. Do a forum search here to find the particulars.
Other issues:
-The hydraulic reservoir has the green lid, close by to the driver's inner fender.
-The anti-lock brakes may have an on/off switch in the row of centre switches; and the switch may be broken. You can test the switch for continuity.
Get yourself a little owner's manual that would have come with the car; and check out 20v.org if you haven't seen it already.
#5
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FYI sir, that finned box in your photo powers your engine's injectors, so even if defective, it may not be your issue. Is the lid and gasket for the fuse panel proper fully secure and water tight?
If the problem occurs after a trip through the car wash, perhaps some time spent with a simple garden hose with a spray gun attached may help you pin-point the location of the vulnerable components.
When the turn signals are working; and when the four-ways run by themselves, do they always flash at the same and proper speed? Do they cut in and out?
Another couple of checks that might be helpful is to see if:
- there is any corrosion on any of the bulb bases &/or receptacles;
- there is a constant drain on the battery with the key off;
- the chassis wiring to the turn signals has been altered/damaged (was a tow hitch ever put on the car?); &
- see if there is water &/or corrosion in any of the rear turn signal housing electrical spade connections.
If your ignition switch has not been replaced recently, perhaps it would be helpful to eliminate it as it is a common failure, and it is cheap and easy to do. Do a forum search here to find the particulars.
Other issues:
-The hydraulic reservoir has the green lid, close by to the driver's inner fender.
-The anti-lock brakes may have an on/off switch in the row of centre switches; and the switch may be broken. You can test the switch for continuity.
Get yourself a little owner's manual that would have come with the car; and check out 20v.org if you haven't seen it already.
If the problem occurs after a trip through the car wash, perhaps some time spent with a simple garden hose with a spray gun attached may help you pin-point the location of the vulnerable components.
When the turn signals are working; and when the four-ways run by themselves, do they always flash at the same and proper speed? Do they cut in and out?
Another couple of checks that might be helpful is to see if:
- there is any corrosion on any of the bulb bases &/or receptacles;
- there is a constant drain on the battery with the key off;
- the chassis wiring to the turn signals has been altered/damaged (was a tow hitch ever put on the car?); &
- see if there is water &/or corrosion in any of the rear turn signal housing electrical spade connections.
If your ignition switch has not been replaced recently, perhaps it would be helpful to eliminate it as it is a common failure, and it is cheap and easy to do. Do a forum search here to find the particulars.
Other issues:
-The hydraulic reservoir has the green lid, close by to the driver's inner fender.
-The anti-lock brakes may have an on/off switch in the row of centre switches; and the switch may be broken. You can test the switch for continuity.
Get yourself a little owner's manual that would have come with the car; and check out 20v.org if you haven't seen it already.
As for the hydraulic stuff and ABS, I'm pretty sure it's not the switch. Earlier this spring, I removed and had the high pressure hydraulic hose for the pump fixed because it was leaking. When I put it back on, the pump wouldn't work. I forgot to prime it, but didn't think that was the issue. Sent it to A1 Cardone to be rebuilt, and they sent it back after cleaning it up and determining they couldn't rebuild it. So I put it back on the car and it seems to be working somewhat this time. Maybe I need to prime it even better than I did the second time? Anyway, the steering seems to be getting too little assist, and the ABS light on the dash comes on too. Occasionally, the brake pedal will be hard, but will stop the car if pressed harder, just not as well as normal; a bit scary the first couple of times. After a brief bit of that, it returns to normal, but the ABS light is still on. I'm suspecting that the hydraulic pressure accumulator is either not getting enough pressure from the pump or is not holding enough pressure. One quiet night, I had the hood up with the battery disconnected and could hear a very faint fizzing-like sound coming from like the top of the accumulator. Maybe that's normal, I don't know. I just barely heard it, and only because my head was pretty close to it while I was looking at something else.
Anyway, that's all for now. I'll investigate further starting tomorrow. Thanks for the help!
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