1978 Bus Rear License Plate Light and Turn Signal Issue

Manfred · Post by **Manfred** » Tue Sep 29, 2009 7:36 am

This is a good one:

This last weekend I was so proud of myself for fixing the light that illuminates my rear license plate. It has never worked since I've owned the bus due to broken wires and tons of corrosion at the connectors.

So last night I drove to the store, turn on my lights, then turned on my left turn signal. It started blinking really fast. So I turn on my right turn signal. It blinks normal. HMMM...something wrong with the relay.

Get to the store. Turn on the left blinker, hop out and run to the back. Rear blinker is working, but really fast and my license plate light is blinking too. Turn on the right blinker. Blinks normally. The license plate light does not blink.

Turn off the head lights. Both turn signals work normally.

I think I know what I did, but wanted to pick your brains first.

BumbleBus · Post by **BumbleBus** » Tue Sep 29, 2009 9:00 am

Gonna follow this one... I'm re-wiring almost everything. Bus I just got came with working headlights and one middle left rear bulb and that was it. Been trying to piece it all back together since. Gotten the two rear sides and license plate light working so far. No turn signal handle so couldn't tell ya if my blinkers work or not yet, let alone if they blink fast. Ha!

Good luck! Post the solution!

Gypsie · Post by **Gypsie** » Tue Sep 29, 2009 9:14 am

Just a guess, but it sounds like the license plate light is now wired in series with the turn signal light and the change in resistance is effecting the flasher rate.

Like I said guesswork.

When you fixed the license plate, did you rewire to spec. or grab some handy power and run with it?

Manfred · Post by **Manfred** » Tue Sep 29, 2009 9:28 am

Gypsie wrote:Just a guess, but it sounds like the license plate light is now wired in series with the turn signal light and the change in resistance is effecting the flasher rate.

Like I said guesswork.

When you fixed the license plate, did you rewire to spec. or grab some handy power and run with it?

That's the thing. All I did was grab the light off my '73 parts bus which was in better shape. It is the exact same light and wiring colors. I then cut the wires with the female connectors off the parts bus, then spliced them to the running bus. I didn't do anything close to re-wiring. I cleaned, cut, and spliced.

I think something is grounding to the body when I turn the light on.

dtrumbo · Post by **dtrumbo** » Tue Sep 29, 2009 9:55 am

Manfred wrote:I think something is grounding to the body when I turn the light on.

Ding, ding, ding! My bet is you have a bad ground which is causing an increase in current causing the flasher to blink too rapidly. Clean, clean, clean your grounds around the tail lights and see what happens.

Post by **Amskeptic** » Thu Oct 01, 2009 8:45 am

Manfred wrote: Turn off the head lights. Both turn signals work normally.

I think I know what I did, but wanted to pick your brains first.

If this bizarre poltergeist (which I witnessed in person) only occurs when the headlamps (parking lamps) are on, your actual mis-wire is between the parking lamp 12 volt supply and the turn indicator supply.

It is not a short to ground, you would merely blow fuses.
Go fix it . . .

Manfred · Post by **Manfred** » Thu Oct 01, 2009 10:03 am

Amskeptic wrote:
Manfred wrote: Turn off the head lights. Both turn signals work normally.

I think I know what I did, but wanted to pick your brains first.
If this bizarre poltergeist (which I witnessed in person) only occurs when the headlamps (parking lamps) are on, your actual mis-wire is between the parking lamp 12 volt supply and the turn indicator supply.

It is not a short to ground, you would merely blow fuses.
Go fix it . . .

The spectacular light show you witnessed was actually with the hazzards on and the lights on. But I'm sure its the same issue. Kind of cool, but I'm on it.

Post by **Amskeptic** » Thu Oct 01, 2009 10:11 am

Manfred wrote: I'm on it.

As befits this the Electrical Forum, a Technical Forum, you shall report your successful resolution of the problem.
Herr Kolin

Manfred · Post by **Manfred** » Tue Oct 06, 2009 9:20 am

My alternator has now gone out. I'm wondering if the two issues are related.

I won't be able to do this repair until I can clear out my parts bus.

Anyone want a '73 bus shell?

chitwnvw · Post by **chitwnvw** » Tue Oct 06, 2009 9:25 am

Maybe you shorted out your alternator. I did that once. It sucked. Turk replaced his with the engine in, so did Vdubtech, maybe Turk will help you out.

Manfred · Post by **Manfred** » Tue Oct 06, 2009 9:31 am

chitwnvw wrote:Maybe you shorted out your alternator. I did that once. It sucked. Turk replaced his with the engine in, so did Vdubtech, maybe Turk will help you out.

Yea Ratwell has a step by step. I think the hardest thing is working in such a confined space.

Vdubtech · Post by **Vdubtech** » Tue Oct 06, 2009 11:36 am

Manfred wrote:
chitwnvw wrote:Maybe you shorted out your alternator. I did that once. It sucked. Turk replaced his with the engine in, so did Vdubtech, maybe Turk will help you out.
Yea Ratwell has a step by step. I think the hardest thing is working in such a confined space.

Bah...there's plenty of room. I did it in the dark with a $3 disposable flashlight in the parking lot of a gas station and had the alternator out before AAA got there....my first time doing so with the engine in place, and there was plenty of room even for my big hands.

chitwnvw · Post by **chitwnvw** » Tue Oct 06, 2009 11:58 am

Yeah, Manfred. With your little girlish hands it shouldn't take you 5 minutes.

Manfred · Post by **Manfred** » Tue Oct 06, 2009 1:12 pm

chitwnvw wrote:Yeah, Manfred. With your little girlish hands it shouldn't take you 5 minutes.

I do have the hands of a carny.

I don't know about there being tons of room. I had a gander under there last night and it seemed like a very tight space to work in with the exhaust and all, but hey it might be easier than I figure, yea right.

Post by **Sluggo** » Tue Oct 06, 2009 5:17 pm

If you pull the fan shroud, oil fill and front tin it's pretty damn easy to pull the alternator.

Itinerant Air-Cooled

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1978 Bus Rear License Plate Light and Turn Signal Issue

1978 Bus Rear License Plate Light and Turn Signal Issue

Re: 1978 Bus Rear License Plate Light and Turn Signal Issue

Re: 1978 Bus Rear License Plate Light and Turn Signal Issue

Re: 1978 Bus Rear License Plate Light and Turn Signal Issue