left rear taillight off

**dab1950** · 05-08-2016, 01:37 PM

Problem: Left rear taillight and 2 of 7 clearance lights are off.
All of these lights worked last year. But this spring I bought LED 1157
replacements for the brake/taillight bulbs. ($15, Wallyworld).
I was surprised to find the left tail light does not light up nor the two
clearance lights directly above it(one on the street side and the left most
light on the rear shell). All of the other clearance lights work and the right tail light too.
I cleaned the socket really well, no help. I swapped bulbs(both incandescent and LED), no help.
Then I pulled the left rear fixture off and found the crimp on splices for both
black and green were very loose. As a matter of fact, they fell apart.
I thought I had an easy fix for the taillight itself and could just live with
the two clearance lights not working, but no luck. Taillight still doesn't work?
Checked the connection inside the lower refrigerator access hatch. There's a
single green wire feeding the rear shell and all clearance and taillights.
That's not the problem. So, my conclusion is that behind one of the two
clearance lights is a splice(or twist lock) of 3 green wires(maybe 4 wires)
and that connection is loose or corroded.
My question for the forum; which of these two clearance lights has the splice of
the main line(green wire) to the other fixtures? I'd rather not
have to remove both clearance lights just for the experience. If someone
else knows which is the one with the main line connection, I'll remove that
one first.
And another question(not electrical) but associated with re-installing these
fixtures; what's the best caulking to use on these?

Thank you in advance for your time and expertise.

Doug

Padgett · 05-08-2016, 01:46 PM

First I'd check the wiring at the socket. LEDs are polarity sensitive.

**dab1950** · 05-08-2016, 01:56 PM

Padgett,

While I highly respect your expertise(I've followed many of your
threads), this is not a problem of polarity. The light bulb socket only
allows the bulb(any bulb whether incandescent or LED) to lock in place
one way.
And I've checked continuity from the taillight socket to the hot contact
of the clearance light above and it's good.
Somewhere in the walls of the rear shell near one of these two clearance
lights is a splice of the taillight circuit main line and the rest of the
fixtures. It's a coin toss I suppose. I just thought, someone else
might have the practical knowledge I lack.

Thank you in advance for your time.

Doug

Padgett · 05-08-2016, 04:43 PM

Never assume. I have seen the leads for a socket on backwards before. Is easy to check. Or just try the original bulb.

**dab1950** · 05-08-2016, 05:42 PM

With all due respect, as I said earlier;
" I swapped bulbs(both incandescent and LED), no help. "

Doug.

Keith Wire · 05-08-2016, 07:49 PM

Doug,

I don't have an answer to your question about: "which of these two clearance lights has the splice of the main line(green wire) to the other fixtures?"

But I have a question for you. Do you have a Volt Meter? The 1157 bulb has two filaments, one for the brake light/turn signal and one for the running light. If I remember correctly the two wires going into taillight are the ones running these two filaments and the ground is obtained from a connection to the frame (skin).

I suspect your ground connection is bad, and it would be easy to check with a volt meter. Just connect your TM to the TV by plugging in the bargman and turn on the running lights and the turn signal. You should see 12v on each line to the TM skin (ground).

You may have already done this, in that case "never-mind"

Keith

Padgett · 05-08-2016, 08:09 PM

OK usually when people come to me they have already tried normal things or think they have so I always start at ground zero. I apologise if I offended.

One alternative is to put the incandescent light in and connect 12v to the marker light and ground to the left turn at the bargman. If the power leads are good both filaments will glow dimly and you have a ground issue.

tentcamper · 05-09-2016, 01:40 PM

When I replaced my rear tail lights. The left side (street side) is where the left and right side wire came together. Did not notice clearance light wires with the tail lights off.

fourteener · 05-10-2016, 07:53 AM

Doug,

Try removing one of the mounting screws and running a temporary ground to it, over the years there have been a lot of issues with the ground related to TM's tail lights and the ground via the aluminum skin (galvanic corrosion). I think there may even be some write-ups covering this very subject. If I had to bet, I would start there.

**dab1950** · 05-12-2016, 05:51 AM

Team,

All very good ideas. I am very adept with a VOM and will go through the suggested checks.
I am particularly interested in tentcampers advice about the main line splice
being near the taillight fixture itself. I've had the left side fixture off and only see one
green wire coming from the tiny hole in the skin. If the main line is near, it's hidden in the wall.

I may have to 'fish it out' and be extra careful not to completely loose it.
I could end up with no taillights and no clearance lights working!

Thanks everyone!