Last week, I had a "crank but no start" condition. A couple of months ago, I left the parking lights on at work and killed the battery, so that with a "2/07" written on the side of the battery, I thought the battery was dead.

Replace with a new Bosch, still crank no start. Finally on the third try, it started right up.

I should mention I've had minor electrical issues that I hoped to fix with some of the electrical maintenance I've read here. The temp gauge jumps when I turn the lights on. Turning the brights on activates the dashboard warning system. The voltage meter "twitches" at low revs and stays between 10 and 12. The PO had also purposely disconnected the clock. When I found that, I immediately thought he was trying to take anything extra off the grid because he has a drain somewhere.

Looking through the files here, I noticed that the PO had installed an extra wire to the positive battery cable, through a fuse, TAPED TO THE GROUND STRAP, around the back of the hatch and back behind the seats. Pulling on this wire revealed that it wasn't connected to anything. Someone had taken care installing this thing, except for the tape job on the ground strap it kinda looked OEM (it was tied to existing wire bundles in the hatch, etc.).

So, remove the wire from the terminal and the ground strap. Car started right up, as usual. Brights work correctly. Temp gauge jumps, but not nearly as much. Voltage gauge is pegged between 12 and 14, except when the lights are on, which I think is still minor issue.

So either the wire, although insulated, was 'interferring" with the ground strap or the ground strap is corroded and moving it around temporarily fixed it. A new strap is on order. Also, will be going through the rest of the ground points this weekend when that order arrives.

So what needs to be directly attached to the battery? An alarm? Stereo stuff? I already pulled some weird wiring from the CE Panel that went up to the front of the roof liner, I'm assuming that was for a radar detector.

 

The symptoms of a bad ground strap do NOT include 'crank but no start'. A bad ground strap will usually lead to no crank or total loss of power - quite likely intermittent esp when physically moving the ground strap.

What you described is something else - and I'll guess most likely totally unrelated to the wiring you found.
whilst messy doesn't sound very culpable. The wire may have been for a charger lead...

Alan

 

MY is a vital piece of missing info here!
FWIW I also HAD the temp gauge kick when I turned the lights on, until recently. I had the pod out to replace the ign switch, and the pod lights. On reassembly I had a pegged gas gauge on side lights, which in the end turned out to be a loss of ground through one of the pod connectors - R13, R9 . If you dash is early (ie 3 connectors, L, R, M) the 'pins' (actually bent split blades) in the connectors are quite soft, and can easly be bent back such that they lose contact with the PCB foil traces - as in trying to trace connections by probing with a DVM. Once I bent these blades back everything worked properly again, and now I dont have the temp gauge kick with lights.....YMMV, but its worth a look. On early cars the L and R connectors are accessible from under the pod.
jp 83 Euro S AT 53k

 

Thanks for the responses guys. Yes, should have included, its a 1982 AT.

Good advice, jpitman2, I'll definately look into that.

I still have a sinking feeling though that I have a drain somewhere. I noticed that the passenger side door jamb button is missing the button. The lights on the door are set to off, and I can't see any light on looking down the door with the window open. I tested in my dark garage, so I'm pretty sure the lights aren't on, even dimly. But could this be drawing power anyway? Excuse the dumb questions, I'm beyond a newb with electrical systems, and the 928's is a doozy.

 

It is surprisingly important to have the complete interior light system working as designed.

 

Thanks Wally, switch is on order. One more thing about the interior lighting. I replaced the map light bulb right after I got the car, since its so easy to do. A month later it went out again. The hatch light bulb is also out, although I haven't tried replacing it yet. Does going through bulbs that quickly indicate anything about the electronic system?

Thanks again.

 

There are red lights in the ends of the doors - these come on with the interior lights - open the door are they on?

Alan

 

Alan

Yes, the red lights on the end of the door come on correctly, only when the door is open, on both sides.

 

Unlikely that having bulbs fail has anything to do with the state of the electrical system. excess current will shorten the life of an incandescent bulb, but that is unlikely unless some how your alternator is overcharging and then it will only affect the bulbs which are lit while the engine is running.

For the extra hot wire coming off the battery, my first thought is stereo amp. What gage wire and amp fuse was it that you removed?

 

My experience is that the alarm circuit will drain the battery if the door switches or hatch switch are not clean.

Ground strap refresh is smart. So is cleaning all grounds and removal / cleaning of CE panel. This done?

Smart --- stripping out the old scab wiring. Sounds like you are on the right track. Best to address all now, before cold weather.

 

76FJ55, I'll check when I get home. The fuse is pretty massive, however. I thought stereo equipment too, but the speakers in the doors are obviously stock since the bass buzzes terribly.

A charger makes more sense, given the size of the fuse and the PO's apparent (unsuccessful) effort to hunt down the draw. Weird though, that the wire would go under the seats. Unless the dealer I bought it off of was trying to hide it, since they didn't know what it was either.

 

Landseer--Full electrical maintenance is next on my list when the ground strap arrives, with special attention paid to the engine-to-chassis one that seems to cause a lot of issues. Is there a part number for this wire? I'd sooner replace it than clean it, but a search didn't turn it up here.

Ok, dumbest question posted on rennlist ever: How do I tell if I have an alarm? So far, there's no indication that I do. I have forgotten that I have locked the car and therefore tried the door handles when locked, so if I have one, its very poor. Nothing out of the ordinary in the CE panel (other than the radar detector wire I previously removed).

 

Roll the window down. Lock the door. Reach inside and open the door. If you have an alarm, it should go off.

 

just trying the door will not set off the alarm. you would actually need to open the door. the factory alarm works off the interior light circuit and a contact switch under the hood. So to test the alarm roll the window down, close the door and lock with the key. then reach inside through the open windos, unlock and open the door. this should set off the alarm provided the alarm is armed and the door contact switch works.

Do you have the long or short key? the long key arms the alarm the short key will not.

Dang, Wally beat me

 

WallyP and 76FJ55-- Fascinating! I'll try this when I get home.

I do not have original keys, I don't think. I have two keys, one red and one black, both the same size. The owner's manual mentions a 'flashlight' on the key, which is why I'm pretty sure they are not original. Such are the small issues I have since I bought this car off a dealer and had it shipped. I really should look up the PO.