Mrmerlin

NOTE as Dr Bob suggested , the same can be said about the seat switches .

AND if you shoot the relays after the car has been driven then parked for 10 mins ,
If you do have an issue you will find a relay thats warmer than the rest of them.

Otherwise I would disconnect the battery till the issue is found.
Their is no need to kill a new battery with a system that could have a constant drain on it.

Alan

For the 10A setting you usually need to use a different terminal... when you know the size of the leakage - it will help to figure out what may be active. Do your interior lights work correctly? do the windows work with the key out - after a door is opened?

Alan

Bales

Lots of replies, thank-you for your thoughts!

Stan - I did wonder for a moment if you were pulling my leg... stand on one foot, whistle at the moon... but of course you weren't! What are the rear door edge lights?

The battery also went flat while I was out at lunch (ironically at a 928 meet up), and the roadside assist guy tested the car at the same time as the battery and established something was drawing current when everything should have been off. He said it fluctuated a bit also.

Were the doors shut and alarm on when I tested, no. I simply wouldn't be able to fit in the car and test in that scenario! Logic would suggest that would only impact circuits that the lights/alarm are connected to? But I'm guessing since you're asking about that there's a good reason...

Windows do not work with key out. Neither switch is stuck.

Little red lights on drivers and passengers doors working when opened.

Interior light both above rear view mirror and on the hatch are not working. Rear light the fixture is broken and bulb removed, front light not immediately apparent what is wrong with it. While these might cause the issue neither or both would seem capable of draining a battery very quickly.

Interior lights on drivers and passengers door near the footwells both work. IDK what each setting does exactly but I have them in the mid, off, position.

Ground strap could be original, both ends have been well cleaned.

My multi-meter is pretty cheap, I think it's electronic but that's the settings it has.

I don't have an IR gun to hand, and they are not that cheap here, might be able to get my wife to borrow one from work.

In the interim it sounds like it might be productive to test everything again with doors shut and alarm on? Not quite sure how I'll manage that but some form of human origami will be required. I assume by alarm on you mean just locked (I don't seem to have a separate way of arming)?

Alternatively if you think the lights are a potential issue I fix those and see what happens next.

Mrmerlin

With more information it’s clear that you need to fix your interior lights first disconnect the battery before you touch anything in the roof otherwise you could shoot out a whole harness to the CE panel everything I’ve told you so far is straight on the money I’m not pulling your leg I promise answer Allen’s questions and be specific disconnect the battery before you touch anything in the roof

You should replace the roof lamps with the new Jetta lamps and you’ll need the short harnesses to go with the lamps so you can tie them into your harness make sure you heat shrink the connector so that I don’t short out

Bales

Thx Stan. Does Roger stock the lights? Had a quick look on his site but can’t seem to find.

Allen - lights work as described above, sorry if I’ve missed anything. Windows do not work with the key out, door open or not.

Shark2626

It sure seems like you just had a dying battery. It failed you within (presumably) less than hours after a drive to your 928 meet-up. Doubtful that a tiny door light could cause that. You should be able to leave your radio, turn signal, hazard lights, or even your headlights on for a period of time and the battery should still have had the capacity to start the car. It’s called Reserve Capacity, every battery has this. Read here:

https://www.hotrod.com/articles/car-...ers-explained/

Now that you have a new battery your issue may very well be solved. Look in to that, see if it is solved, before diving deeper looking for an issue that may not even exist.

Billu

For interior lights, switch at one end should be light on constant, switch at other end light should turn on and off with door open/closed, center off.
Check red door lights for off, not on. Either try to peek with doors and hatch closed or open door and manually push door switch to confirm they shut off. Most common cause of light not shutting off is hatch switch.
Check wiring for the two non-working lights, brown and brown/white should be on the same end. Brown is ground, brown/white is switched ground through the door and hatch switches.
Batteries now don’t seem to take total discharge very well. Even a relatively new battery won’t always recover from total discharge.

Bales

Quick update: Red light on the ends of the door are permanently on. Interior lights on the doors do not turn off in the up or down position regardless of door position. Might these 2 things mean the door switches are not working? Removed interior lights overhead in cabin, both have cracked plastic on the ends but no reason I can see that the light fitting itself should not be working. Tested ground strap, is passing through a full 12.5v. All I have time for tonight...

Dumb question: The overhead interior lights have no switches, so should they only work when doors/hatch are open?

FredR

I cannot remember what the wattage of those interior lights is but remember they are incandescent and draw more current than one might think. Note that a 12 watt drain would draw a current of one amp and such a load will flatten a good battery in 65 hours [to give some perspective]. A knackered battery will discharge in way less time dependent on what its capacity currently is.

Your comment about the ground strap does not appear to make much sense at face value. Ground straps can and do fail where the braid enters the solid connector at each end. Peel back the plastic insulation half an inch or so and take a look at the condition. If you see a lot of the strands are fractured and/or lots of oxidation the strap is pretty much toast. You should also check the condition of the engine ground strap- on LHD drive models it is at the back of the engine on the passenger side- not sure about RHD models but it is easy to find.

Shark2626

Your questions have already been answered at least twice now, just go back a post or three. But I’ll give it a shot for you and see if it sticks.

The lights that you referenced are 3-way switched, even if they have no actual “switch” - just press the fixture to switch positions. The 3 positions are: On, Off, or On/Off with the door or hatch opened or closed. Try your door light switches again, try all 3 positions - IIRC Billu noted that “center” is off.

Make sure that the hatch is closed when you are observing your lights functions.

Billu

Disconnect the hatch switch, see if that makes a difference.
Also, check wires on each light, brown and brown white should go to the same end of the fixture, colored to the other end.
disconnect the brown wires, these are the constant ground.
Having the wrong wire in the wrong place can cause this.
Yours being a 1990, I think you might have a relay for the light circuit rather than direct power to the switches, but that would have to be confirmed by others.

dr bob

The roof lamps are "rockers", where you tilt the lamp itself to get the options.

The ground side of the circuit is connected to the door switches but runs to every lamp. If you can disconnect the door switches and the lights are still on, there's a short to ground in the switched-ground wire that runs to every interior lamp in the car. Favorite places for rub-through faults are above the headliner, inside the hatch and where the hatch wiring passes through to the hatch. The other favorite spot is at the lamp over the rear-view mirror.

Alan

What you described is interior lights that don't fully work. If the lights don't work in the door switched mode - then your your door end lights are always on and maybe also your power window controller too (I'd expect so). You need to fix this first - lots of threads on this.

I believe from what you have said that you likely have several things going on together.

1) A damaged battery that needs replacing (just barely good enough when charged as much as it will take)
2) Interior lights that don't work that are causing a gradual battery drain (likely several days to discharge)
3) Some other issue that makes you think the battery can go dead in a matter of minutes.

Number 3 could most likely be:
- "After running" of the fans (if the car has got very hot - do you hear the cooling fans running after you shutdown? A good battery can handle this - but yours maybe not
- An intermittent battery ground strap - next time the car seems dead aggressively wiggle the ground strap - OR just order a replacement - a good preventative step

Alan

Bales

Thanks in particular for the last few posts, the specifics have been super helpful. I was looking at the switches after I pulled them out, looking at the little round pins at each end, and wondering "why did they design them like that?" Dr Bob's post suddenly enlightened me! Mine did not rock/move at all when I pushed on them because they were broken...

Haven't had much time to look at the car over the last 2 weeks but did remove the interior lights for now and it seems can't get replacements locally so ordering them from Roger complete with pigtails. I did have time to pop the door switches out and apart from bare end of wires that could potentially touch metal (wrapped in tape now) they don't seem to be the issue. No obvious sign of wiring issues from a quick visual inspection. Need more time to look properly.

Did fit the new battery, took her for a drive, and new problem, engine won't turn off with key. Pulled the fuel pump fuse to get it to stop. Looks like lots of threads on this, another thing for next weekend.

On a more positive note, finalising parts list with Roger for my intake refresh and she's booked in for July to get this done :-) If I can't sort the electrics myself before then I'll probably ask my shop to look at it while its there.