TheSamba.com :: View topic - Reverse lights

Sat Feb 23, 2008 8:07 pm

I have a 67 bus with non-working reverse lights. I plan on going under and checking the wiring from the tranny but here's the question? Do the reverse lights normally turn on when the key is turned on to first click (but engine not running) and the shift is in reverse? I ask so I can check by myself safely and without the risk of my wife running me over while I'm underneath!

I'll also post this in the bay forum since most splits except 67 don't have the back up lights...Thanks guys

Sat Feb 23, 2008 8:19 pm

ignition must be on(power to the coil) no need for running check the fuse by the coil first

Sat Feb 23, 2008 9:48 pm

slow36hp wrote: ignition must be on(power to the coil) no need for running check the fuse by the coil first
Agreed - with test light or voltmeter - check for voltage at hot side of coil, and then both sides of the inline fuse. If you've got it there but not at the actual light assemblies, the only things left are the switch on the nose cone of the tranny, or the wiring to and from the switch. The fuse goes to one side of the switch, and the other side goes to the reverse lights.

That said, you could also have bad grounds at the lights or bad bulbs.

diagram thanks to Speedy Jim ...

Sat Feb 23, 2008 10:01 pm

mine also didn't work, found out the screws securing them were not seated well therfore the ground was week. may check that as well.

Sun Feb 24, 2008 3:19 pm

thanks for the tips guys...esp the wiring diagram and possible grounding issues!

Fri Jul 17, 2015 8:43 pm

Digging up an old post.... Troubleshooting my backup lights on my 67 (factory lights and wiring harness) as the driver side light will not light up (passenger works fine.) I have power all the way to the wire which plugs in to the drivers side light but still nothing. Tried multiple bulbs with the same results. Could their be a short in the housing?

Thanks

Fri Jul 17, 2015 9:37 pm

If there was a short one of two things would happen.

1. Blow fuse.

2. If no fuse wired in the system, wiring would start to smoke....

Fri Jul 17, 2015 9:40 pm

Fuse in place and it's not blowing. Test light shows power
Is getting all the way to wire end of the drivers side.

Sat Jul 18, 2015 4:22 am

so if I understand you correctly, consistent power gets all the way to the end of the wire where it plugs into that bulbholder (your test light lights up there). So the fault is either in the grounding of the bulbholder (rig up a temporary second ground wire from the bulbholder to a known good ground) or in the bulb (test continuity of the bulb with a simple multimeter) or a defect in the bulbholder itself (try another bulbholder in place).

Bill

Sat Jul 18, 2015 7:10 am

srfndoc wrote: Digging up an old post.... Troubleshooting my backup lights on my 67 (factory lights and wiring harness) as the driver side light will not light up (passenger works fine.) I have power all the way to the wire which plugs in to the drivers side light but still nothing. Tried multiple bulbs with the same results. Could their be a short in the housing?

Thanks

Fuse in place and it's not blowing. Test light shows power
Is getting all the way to wire end of the passenger side.

You have two conflicting posts (bold.) I assume the second one was a typo and you meant to write "driver's side", correct?

If so, the only thing left as a possible problem is the light fixture itself. You need to disassemble the fixture and see if you have continuity to both parts of the light socket--the center of the socket must have continuity with the wire and the side of the bulb socket needs to have continuity to the outside housing (ground.)

Sat Jul 18, 2015 8:30 am

Those housings have a funky point to dig in and scratch a ground.

Sat Jul 18, 2015 8:55 am

olliehank47 wrote: srfndoc wrote: Digging up an old post.... Troubleshooting my backup lights on my 67 (factory lights and wiring harness) as the driver side light will not light up (passenger works fine.) I have power all the way to the wire which plugs in to the drivers side light but still nothing. Tried multiple bulbs with the same results. Could their be a short in the housing?

Thanks

Fuse in place and it's not blowing. Test light shows power
Is getting all the way to wire end of the passenger side.

You have two conflicting posts (bold.) I assume the second one was a typo and you meant to write "driver's side", correct?

If so, the only thing left as a possible problem is the light fixture itself. You need to disassemble the fixture and see if you have continuity to both parts of the light socket--the center of the socket must have continuity with the wire and the side of the bulb socket needs to have continuity to the outside housing (ground.)

That was a typo, should have said power to end of wire on drivers side. How does the housing get its ground since it's completely surrounded by the rubber seal?

Sat Jul 18, 2015 9:29 am

If you can believe it, just through the two screws. You can add a jumper as a ground very easily- just as is often done with the taillight housings. There is no crime in drilling a small hole in the reflector for which to screw or rivet a ground wire.

Sat Jul 18, 2015 10:11 am

hitest wrote: If you can believe it, just through the two screws. You can add a jumper as a ground very easily- just as is often done with the taillight housings. There is no crime in drilling a small hole in the reflector for which to screw or rivet a ground wire.

That's what I thought but seemed sketchy. Another question I have involves two different types of housings I have. My original housings had the section where the screw goes in to torn out so I bought two new OG housings that came with an extra connector. It almost seems like this could be used for a ground.

Old

New

Part numbers on each housing are the same and both made by Hella. The newer housing is the one that is not working but the other new housing on the passenger side works fine.

*Edit - Not sure about the housing but the little rubber boots they came with seem to be from a Type 3 (part number 311945281):

Sat Jul 18, 2015 6:30 pm

Yes, that extra connector on the newer lights to for a ground wire.

If that's the bad fixture in the photo, notice the corrosion around the hole where the bulb fits--that's where the ground is made and it should be cleaned up. You can easily test continuity of the hot connection and the ground connection of the fixture with it apart. You can even put in a bulb, connect the hot wire to power and touch a ground wire to the fixture body. If the builb lights, the fixture is good and your problem is a solid ground of the fixture to the chassis.

Sat Jul 18, 2015 8:13 pm

If you don't want to drill a hole in the light housing you can use a small nut on the backside of the mounting screw and attach a small eyelet electrical connector. Clean the contact area on the housing and use dielectric grease.

I always add a ground to my taillights this way and they are bright and trouble free; a must for those running 6 volts.

Sun Jul 19, 2015 9:38 am

BarryL wrote: Those housings have a funky point to dig in and scratch a ground.

This is from the kind with a separate ground but it's the same casting.

This is where the sharp point was, one at each side by each screw.

Here's where it touches the body steel to make ground through the rubber.

Here's the whole schmeer assembly.

Sometimes you can just reach inside the engine compartment and wiggle-scratch the whole unit into submission ground.

Sun Jul 19, 2015 10:49 am

The issue definitely appeared to be ground related after doing some additional troubleshooting. I took Doug's advice and took advantage of the extra ground post on the newer housing and ran a ground wire to the back side of the tail light housing just below:

That did the trick and I'm back in business:

Thanks to all for the assistance.

Sun Jul 19, 2015 10:56 am

Curious, are the reverse lights activated when you put tranny in reverse? I haven't gotten that far yet on my 67. Housing is installed, just no power yet.

Sun Jul 19, 2015 11:21 am

Yes, as long as the ignition is on (turned to the first click). No need to start the engine. I had my trusty helper (my oldest daughter) clicking it on/off as I was testing everything.