Bad Ground??
08-11-2013, 06:56 PM
#1
Track Day
Thread Starter
Join Date: Apr 2013
Location: Chicago, Suburbs
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Bad Ground??
I have what I think is a bad ground problem but am stuck with diagnostics.
Here’s what I have. 1990 944 S2 Cab. Running great until yesterday when I noticed the brake lights were stuck on.
I thought it would just be a bad brake switch, but no. when I press the brake the whole dash lights up with every warning light there is and the chimes going off.
Ok, so it is just a bad ground maybe… I start by cleaning all the grounds MP11, MP111, MPV1, MPV111, MP1X, and the rear ground by the spare tire (MPV11 I think?). everything was pretty clean but I did them all anyway, no change.
I then started removing fuses to see if that isolated the problem. So far the only one that changes the fault is fuse #19 for brake light, cruise cont. and ABS. I can also hear a clicking a couple of times at the front right side of the engine bay area when i press the brake, but, I’m on my own and can’t get closer to hear exactly what is clicking?
If the engine is running there are no warnings, and the brake lights shine a little brighter when the brake is pressed, but won’t go off.
So my questions are;
1. What can I look at next?
2. could this be an ABS problem and is there a better check than what I’ve done so far?
Here’s what I have. 1990 944 S2 Cab. Running great until yesterday when I noticed the brake lights were stuck on.
I thought it would just be a bad brake switch, but no. when I press the brake the whole dash lights up with every warning light there is and the chimes going off.
Ok, so it is just a bad ground maybe… I start by cleaning all the grounds MP11, MP111, MPV1, MPV111, MP1X, and the rear ground by the spare tire (MPV11 I think?). everything was pretty clean but I did them all anyway, no change.
I then started removing fuses to see if that isolated the problem. So far the only one that changes the fault is fuse #19 for brake light, cruise cont. and ABS. I can also hear a clicking a couple of times at the front right side of the engine bay area when i press the brake, but, I’m on my own and can’t get closer to hear exactly what is clicking?
If the engine is running there are no warnings, and the brake lights shine a little brighter when the brake is pressed, but won’t go off.
So my questions are;
1. What can I look at next?
2. could this be an ABS problem and is there a better check than what I’ve done so far?
08-11-2013, 07:19 PM
#2
Drifting
Check your battery voltage with engine off...12v. Engine on....over 13.5 volts. Sounds like the battery's very low and there's not enough voltage to make everything work like it should.
08-11-2013, 08:04 PM
#3
Track Day
Thread Starter
Join Date: Apr 2013
Location: Chicago, Suburbs
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
ok, crisis solved. Thanks mytrplseven, battery was fine.
I went back and checked the grounds again, I couldn't believe i'd missed it but the MPV ground under the right headlight runs to a white connector block, that was where the bad connection was and where the clicking must have been coming from... as usual it's the last place you check that the fault is at.
So, everything is back to normal again.
I suppose the good thing here is that I was at home when I found it and had all this weekend to play with it. (always look for the silver lining
)
I went back and checked the grounds again, I couldn't believe i'd missed it but the MPV ground under the right headlight runs to a white connector block, that was where the bad connection was and where the clicking must have been coming from... as usual it's the last place you check that the fault is at.
So, everything is back to normal again.
I suppose the good thing here is that I was at home when I found it and had all this weekend to play with it. (always look for the silver lining
)
08-12-2013, 10:54 PM
#5
Rennlist Member
Excellent, whenever you have a problem as you described, it is a bad ground. I just got a 968 so I am just reading these forums.....it sounds like you knew exactly what to do.
If anybody else searches and finds this post later....follow Bill's advice and you will solve your issue.
If anybody else searches and finds this post later....follow Bill's advice and you will solve your issue.
