First post! grounding issue...

[cjw]

I have been through 3 E30's and an E34, but recently I picked up a non-running `77 E12 in remarkable (for around here) shape. I finally have it running, and now besides trying to reassemble the interior (it was apart when it arrived) I have an electrical gremlin to hunt down.

I'm pretty sure I have a poor ground and it is backfeeding, but I'm not sure where all the grounds are. I have consulted the electrical diagram and searched the forum, but I'm still not sure where to start. These are the symptoms:

- the brake lights are always lit (once the key is turned past the first position)
- the brake warning light is lit when the car is running
- the turn signal indicator is dimly lit solid when the car is running (the signals operate correctly when switched though)
- windshield wipers are on intermitant and won't shut off

The wipers are confusing me a little on their own and may not be related. The wiper stalk appears to have three positions: fast, slow and int. There does not appear to be an "off" position. Am I missing something? Or could it be a switch out of the "wrong" car?

I know you should never buy a basket case, but I shudder to think where this one was headed if I hadn't picked it up.

I only got it running last night... I'm looking forward to taking it for a quick spin around the block (today if it stays nice)!

Thanks for any help,
Chris

[DEMIURGE]

1. the brake lights are always lit (once the key is turned past the first position)
2. the brake warning light is lit when the car is running
3. the turn signal indicator is dimly lit solid when the car is running (the signals operate correctly when switched though)
4. windshield wipers are on intermitant and won't shut off

Hi Chris,
You are probably right - there is ground problem... This could be the reason of the dimly lit indicators. They are probably lit through the brake lights (without ground).

Possible faults:
1.1. Ground problem
1.2. Faulty switch
1.3. Short circuit (wires)
Try to connect with a suitable wire the tail light ground (brown wire) to the chassis. The common tail ground (all brown wires) must be somewhere in the trunk.

2. Which brake warning light is lit? The brake pad or the handbrake warning light. If it is the first - check the brake pad sensors - maybe it is worn or broken. This light is lit in conditions of short OR open circuit!
If it is the handbrake light - check the corresponding switch under the handbrake lever.

3. Maybe it is the same ground problem - Check with a new ground wire as in the first point.

4. There is an "off" position. Maybe the switch is faulty. After checking the switch and it is OK - check the wipers relay.

[alotawatts]

Welcome !
On later models the gang/ground points outside of the engine bay are up behind/under the instrument panel - top of firewall, in the trunk between tail light and license plate and under the back seat.

[Blaise]

Welcome !
On later models the gang/ground points outside of the engine bay are up behind/under the instrument panel - top of firewall, in the trunk between tail light and license plate and under the back seat.

Yes...under the back seat...on the right side. I just cleaned mine up

[cjw]

So, an update (I know, it's been a long time...)

I have solved at least some of my issues. After cleaning all grounds multiple times, I started the (very long) search for my mystery power. It turned out that the cigerette lighter plug was at least one of my culprits... actually, it was the previous owner. It appears that he may have installed and then uninstalled a stereo. The leads for the lighter plug were reversed (the butt connectors were hidden futher back up the circuit) and the power was actually arriving at the ground side of the lighter scocket and then travelling backwards through the illumination bulb, lighting the dash lights and some marker lights in the process.

So that I know what I am starting with (or what should be happening), the next thing is wipers. I have a switch with three positions (and then a pull back and push in function). What this gives me is:

Top: Fast
Middle: Slow
Bottom: intermitent

So... I have no "off" position. What should those positions do on an 06/77?

I assume "off" should be bottom most, but then where do the other three belong? I am wondering if it's even the right switch for the car (it looks right, but...)

I'll keep working my way forward little by little, but any help is appreciated!

Thanks,
Chris

[cjw]

Forgot to say.... turned out the brake lights were on simply because of a poorly adjusted switch. Haven't figured out why the dash light is on though (it is the brake one, not the one for pads). Ebrake switch and fluid level switch both check out...

Chris

[Lenny D.]

Hi Chris and welcome...I can't speak to a '77 directly but I will hazard a guess your wiper problem lies inside the wiper motor assembly. There is a cancelling function acutuated mechanically (I believe) that is probably broken, misaligned or gummed up to the point it won't work properly to make the motor fully stop. The third (fully down) position of the stalk switch is 'off', but governed by the wiper motor assembly, so I would look there, after wrangling the motor and linkage out from the cowl. They could use cleaning, regreasing and the motor will disassemble for cleaning and regreasing as well. You may find broken parts inside and then you're on a hunt for a used motor (to open and inspect before reinstalling).

I suspect your brake light is a misaligned switch inside the parking brake not fully closing.

[Falkenberg]

My '76 has a wiper switch with 4 positions, on the right side of the wheel. And when you pull it, the windscreen washer activates. It is the old style switch, with a round head. I don't think I can push it.

If yours has three positions, pull and push (does it stay in the pushed position until you pull it back?) it sounds like it is a turn / indicator switch..?