Crazy Electrics

[findon]

New here, but have decided it's time I joined a forum if we are serious about VW ownership Had our van for a year with very few problems (except a wheel nearly coming off and a dodgy alternator and carb...)

On a drive back home last night in the dark a load of weird electric issues started... I assume they could all be related, or maybe not.

1. Before darkness descended - battery indicator light came on at the start of the journey (battery was charging, so ignored - has happened before, generally goes off with high revs). Seemingly nothing else wrong.

2. On turning at a roundabout the horn suddenly started going on and off and the headlights were switching themselves to full-beam seemingly at random (it was dark by now, so we had the headlights on), weirdness continued after coming off the roundabout whilst keeping the steering column steady.

3. Noticed on pulling over that one of the rear lights was working OK but not when braking...

Spent the next few miles with loads of people flashing at us, as if our headlights were too bright...

Trundled home and keen to look at some of this tomorrow, I am guessing the relays and the wiring in the steering column should be my first port of call?

Thanks for any help in advance!

[Jeff Geisen]

If I experienced this sort of thing in my rig my first suspect would be the turn signal switch.
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‘63 ragtop - ‘68 single cab

[busdaddy]

My guesses are:
1= severely worn brushes
2= signal switch as Jeff suggests
3= bad grounds on the offending light fixture.
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[Tram]

[telford dorr]

^^^ X3 ^^^

While one would logically assume that all simultaneous failures have a single cause (logically the most probable), it isn't necessarily the case. isn't it great when a half dozen things seemingly all go wonky at once. It happens. The solution is to fix them, one at a time. Diagnose, repair, go on to the next.

Persistence furthers.
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'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[findon]

Thanks for all the thoughts people! In short this sounds like a potentially complex mess in comparison to my previous minor fixes... not really sure where to start!

[KentABQ]

[findon]

OK so the battery light...

Without engine on... solid reading of 12.69V... NO Battery light obviously

Ignition turned, engine off... voltage slowly dropping.. BRIGHT battery light

Ignition turned, engine on, continues to slowly drop (has always taken an initial press of the accelerator pedal to get the alternator to kick in)... BRIGHT battery light

After accelerator pressed briefly to kick alternator in, voltage starts to rise, battery light goes dim, but doesn't go off.

Then when driving the battery light appears to be directly connected to the accelerator pedal, basically going bright when pressing it down and going back to dim when releasing.

Battery tester (which also includes alternator tester) seems to think all is good and the voltage rise once the alternator has kicked in would seem to concur. Does this just sound like a wiring issue?

I guess it could all be related to the other listed problems (haven't been able to replicate the horn, headlight flicking one)...

[Zed999]

With it charging you should measure ablut 14v.
If it's, say, 17v your regulator is broken.

[telford dorr]

Repost this with voltage readings on both the alternator/regulator B+ and D+ terminals. Numbers will greatly aid in the creation of an accurate diagnosis of any alternator issues.

Also post model year and engine type (1 or 4).

[SGKent]

First - and I mean absolutely no disrespect but the descriptions of the problems could be quick observations and not a detailed description. Here is what I mean - were the high beams actually coming on - where the relay clicked and the high beams illuminated, were the high beams coming on with the relay never clicking, or was the decision they were on simply because other oncoming cars were flashing the bus due to overly bright lights?

Let's first look at just this one symptom. How much weight was in the back of the bus? Could the rear have been low making the headlight appear high? Did the blue high beam indicator light come on? If a ground lifted could the high beams back feed where they came on without the relay engaging them? Or if a diode was blown, and AC got into the system, or the voltage regulator was acting up could low beam flaring lights be mistaken as high beams? Did anyone verify that the high beams were actually on?

As to the back - is this really a case that all happened at once, or was this an, "I better check everything else," - resulting in finding other things that were already wrong? Or did high voltage - caused by a shorted diode, or bad VR cause the bulbs to burn out?

I really think that before the OP can troubleshoot this he will need to take some very accurate checks to see what is actually happening. To start, having the alternator indicator come on implies that the system is not charging. Finding 12.69 V means nothing if the battery is still at a full charge - the correct measurement at RPM should be around 13.5 - 14.0 V, assuming that the meter is calibrated properly which many meters are way off.

I would measure the battery voltage at the posts with the ignition off. Then start the bus and see what the voltage does. Probably it wouldn't hurt to clean the battery cables first just to be sure the connections were good between the battery cable and the post. With everything off I would use a 12V inductive ammeter to see if there was any drain. That can happen if the VR is one with points and they stick. It can also happen with a bad diode in an alternator. A sharp rap on the VR box with a screwdriver handle might unstick welded points temporarily.

IMHO, once the OP looks over things more closely he should report his findings back.
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[findon]

Sorry for ignorance, new to all of this!

It's a Type 1 1600 re-con engine (AD prefix), Van is a 1973

Looking at it, starting the engine doesn't cause a big jump in the value of the voltage, it just slowly ticks up... that's likely bad I assume.

Will happily grab a value from the alternator if i can work out where to do it!

Thanks for all the help so far.

[findon]

[telford dorr]

No problem. You most likely have the Bosch AL82N type alternator which has a large lug terminal (B+) for the output power and a small 1/4 inch blade terminal (D+) for the dash indicator lamp. You can take the voltage readings directly on those two terminals. Do be careful to keep your meter test leads away from the moving fan belt! If your alternator configuration is different than as described here, let us know.

Do not 'assume' that the alternator is defective, as there are external factors which can cause the same symptoms.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[findon]

Quick engine pic

[SGKent]

[findon]

In answer to your questions (as much as I can remember, we were a little panicked at the time as it was all pretty new to use and we had a sleeping 3 and 5yr old in the back)

1. The relay was clicking and the blue dash light was definitely coming on and the high beams were definitely switching (from memory they were only ever switching from LOW to HIGH on their own, i.e. whenever we switched back down to LOW, they would flip back up - not always instantly though, the horn was also intermittent).

2. The symptom of other cars flashing at us only started when we moved off again (the automatic switching / horn beeping problem never repeated itself during this part of the journey), so I can only assume that this was in fact just people mistaking low beam for high due to weight and us being paranoid!

3. As you say, the rear light issue may have been there for ages, it was only noticed as a result of the panic after we pulled over.

[findon]

Will have a look at it all again tomorrow, wondering if i've just got a loose/slipping belt now I have sat and thought about the symptoms. EDIT: Seemingly not the answer, deflection on the belt seems fine, around 14mm.

[findon]

BATTERY LIGHT ISSUE
So the big lug is giving out 13.4v (relative to ground) with the engine idling, but goes up to around 14.7v when accelerating.

The blade one is 15.6v at idle and goes up to over 19v when accelerating

REAR LIGHT ISSUE
You will be pleased to know I diagnosed this one: One of the little bendy metal clips that goes into the bulb holder - no idea what this is called - had snapped, so the lead was just hanging free (is there a chance that this could have been somehow touching the bodywork or something else and causing the odd headlight/horn issue?)

The bulb holder is similar to this - https://www.justkampers.com/311-953-071-reversing-...-bays.html - except that it has two contacts to the same bulb (one for brake contact and one for rear light contact), i'm sure i will find a replacement somewhere...

[telford dorr]