Our Favorite Electrical Gremlins of the 928
#1
Three Wheelin'
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Our Favorite Electrical Gremlins of the 928
Let's hear them. I'm sure most of us have them. Well, maybe not Alan or those others of us that are much smarter then I am.
Here's a couple to start with...
I was driving home last night and noticed my passenger side mirror pointed at the ground... it resets to that position on every fifth or so start up.
It's on the: "maybe I'll chase that down someday but for now I can put up with it" list.
My other favorite: oil pressure pegged unless engine run for long periods, AND with clutch pedal engaged... then perfect readings!
Here's a couple to start with...
I was driving home last night and noticed my passenger side mirror pointed at the ground... it resets to that position on every fifth or so start up.
It's on the: "maybe I'll chase that down someday but for now I can put up with it" list.
My other favorite: oil pressure pegged unless engine run for long periods, AND with clutch pedal engaged... then perfect readings!
#3
Burning Brakes
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The oil pressure sending unit may need to replace, mine was like that for a while then one day it just read zero, put a new one in and now its steady all the time!
My cruise control works sometimes, most time not, don't use it even on highway so...
My speedometer doesn't work when the car is cold after a couple miles in and warm up, the needle will rise and work for the rest of the day.....
My cruise control works sometimes, most time not, don't use it even on highway so...
My speedometer doesn't work when the car is cold after a couple miles in and warm up, the needle will rise and work for the rest of the day.....
#4
Administrator - "Tyson"
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You mean the coolant temp gauge in my 87 is supposed to work without me hitting the pod?
#5
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Will you hit me if I say I don't have any at all?
#6
Official Bay Area Patriot
Fuse 24 Assassin
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#7
Nordschleife Master
The gas gauge is the one that doesn't work until I hit the pod. I basically have a choice of which one I want to work.
I need to yank the pod and go through the connections (again).
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#8
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My favorite is when I need to hit the pod because all of the gauges but the tach and temp die and the central warning lights up until I smack the pod then all is fine. (worse when cold)
I also have a dead cruise control ( In my case it's just a bad brain). Everything else works fine though...
I also have a dead cruise control ( In my case it's just a bad brain). Everything else works fine though...
#9
Chronic Tool Dropper
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Only electrical faults on my car so far (almost 20 years of stewardship...) were directly traceable to relay-relay-relay, and grounds-grounds-grounds. AC control head relay, fuel pump relay. Battery ground strap.
The LHA failure is a separate, known but electrically-related issue too I guess.
The LHA failure is a separate, known but electrically-related issue too I guess.
#10
You can call me Otis
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I've posted about this gremlin before, but I believe it was the main reason I was able to gain entry to the $5k 928 club, at a cost of only $5k.
When I test drove the car, ....it ran.
The most annoying problem was that the door chime was constant, parked, driving, always.
After removing both door panels checking wiring, and the over head interior lights, I gave up, it was accidentally that I noticed the rear hatch light, I never seen it, didn't know it was there, any way, took it out and found the plastic was crumbled, and the hot wire was shorting out inside the hatch.
Resolving that cured all electrical gremlins.
...in till the next one popped up, and down, and up again...yeah, the infamous headlight relay. I think there's a thread for that now.
OH What Fun!
When I test drove the car, ....it ran.
The most annoying problem was that the door chime was constant, parked, driving, always.
After removing both door panels checking wiring, and the over head interior lights, I gave up, it was accidentally that I noticed the rear hatch light, I never seen it, didn't know it was there, any way, took it out and found the plastic was crumbled, and the hot wire was shorting out inside the hatch.
Resolving that cured all electrical gremlins.
...in till the next one popped up, and down, and up again...yeah, the infamous headlight relay. I think there's a thread for that now.
OH What Fun!
#11
Rennlist Member
The "piece de resistance" has to be the leak to earth that flattens the battery in no time. Heavens knows how many permutations of cause for this gremlin there are but if you have not experienced this chances are you are about to!
I am not particularly good with electrical issues but I can generally muddle through to an extent with help from this list.
Many years ago on my late 90S4 I had such an issue. could not find the problem so took the easy [not cheap] way out and took it round the local dealers. To my astonishment in no time they traced it to a chaffed cable in the rear hatch area. How on earth they found it was beyond me. One of those things you stick in each fuse holder to measure current most useful- need to get me one of those things. Well worth the $50 bill I got at the time.
The front engine harness dropping to pieces after 20+ years has to be the other one you can set your watch with.
Rgds
Fred
I am not particularly good with electrical issues but I can generally muddle through to an extent with help from this list.
Many years ago on my late 90S4 I had such an issue. could not find the problem so took the easy [not cheap] way out and took it round the local dealers. To my astonishment in no time they traced it to a chaffed cable in the rear hatch area. How on earth they found it was beyond me. One of those things you stick in each fuse holder to measure current most useful- need to get me one of those things. Well worth the $50 bill I got at the time.
The front engine harness dropping to pieces after 20+ years has to be the other one you can set your watch with.
Rgds
Fred
#12
Team Owner
The one I like most is when turning off the engine it keeps on running, even with the key removed.
Old timers here know what to do.
yep put the key in and turn to run,
then pull the defrost relay,
then turn off the engine
Old timers here know what to do.
yep put the key in and turn to run,
then pull the defrost relay,
then turn off the engine
Last edited by Mrmerlin; 05-01-2016 at 10:55 AM.
#13
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I solved all of my electrical gremlins by installing a battery kill switch. I asked if this made me a bad owner and the kind folks here suggested that based on this and this alone, I might still be OK. Oh yes, Greg B thinks my door-end lights/door switch may be responsible for the parasitic drain. I will be getting to this right after blah, blah (endless list goes here) on my other P cars....
#14
Under the Lift
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Driver mirror only adjusts up/down with the door open. Suspect ANOTHER wire break in a flexing fold in the harness that passes into the door at the hinge. It did this before.
LH failure. Only once so far, on the way to work 10 or 12 year ago. Diagnosed and fixed in 30 minutes. Would have been faster but I had to wait for Mark Thomas to drive a rebuilt LH over to my stalled car.
Ignition monitoring system gremlin causing false triggering of 4 cylinder mode. I disabled it long ago.
Headlights turning themselves off spontaneously. Traced to ignition switch evidenced by wiggling key and having them come back on after driving blind in the dark for a few harrowing seconds.
Tail Light Failure warnings for only a couple of days once every year or so that clear spontaneously. I replaced the bulbs with matched pairs and cleaned all the sockets. Still happens once in a blue moon. No bulbs out. Goes away in a day or so. Forget about it.
That's about it. Have seen many electrical gremlins on buddies' 928s, including bizarre parasitic draws (obscure wire shorts SOMEWHERE in the sunroof wire harness that took forever to diagnose; large draw in a little used car traced to rarely used passenger seat back motor that just needed some exercise to break whatever short it had).
LH failure. Only once so far, on the way to work 10 or 12 year ago. Diagnosed and fixed in 30 minutes. Would have been faster but I had to wait for Mark Thomas to drive a rebuilt LH over to my stalled car.
Ignition monitoring system gremlin causing false triggering of 4 cylinder mode. I disabled it long ago.
Headlights turning themselves off spontaneously. Traced to ignition switch evidenced by wiggling key and having them come back on after driving blind in the dark for a few harrowing seconds.
Tail Light Failure warnings for only a couple of days once every year or so that clear spontaneously. I replaced the bulbs with matched pairs and cleaned all the sockets. Still happens once in a blue moon. No bulbs out. Goes away in a day or so. Forget about it.
That's about it. Have seen many electrical gremlins on buddies' 928s, including bizarre parasitic draws (obscure wire shorts SOMEWHERE in the sunroof wire harness that took forever to diagnose; large draw in a little used car traced to rarely used passenger seat back motor that just needed some exercise to break whatever short it had).
#15
1983 Euro 5 speed: dome light in hatch caught fire due to chafed wire. melted wire all the way to plug U on central panel. no fuse protection. Noe starter relay will not energise!