Dash lights come on when brake is applied?

[DarrellG]

I've had my '65 D200 three weeks or so, the rear running lights and brake lights don't work (yet). Rear turnsignals do work. I haven't prioritized troubleshooting and fixin' them yet. I'm just messing around and found something interesting a couple minutes ago...

With the headlights off, even with the keys out, when I depress the brake pedal the instrument lights come on. Hmmm. I've got a fusebox, the instrument light circuit looks to be independent, just a 2amp fuse. So which circuit has the rear running and brake lights? Any idea what could be crossed?

Full troubleshooting to come (I HATE wiring!!!) just curious if anyone had any insight.

Please, please be something simple and easy!
Darrell

[JimE]

Don't hate the wiring, just follow it from a diagram and you may or will find enjoyment in it. Here is your wiring diagram:http://www.sweptline.com/tech/65wire.jpg

I would start by looking at the headlight switch then go from there. Jim

[Jeffc]

I've had my '65 D200 three weeks or so, the rear running lights and brake lights don't work (yet). Rear turnsignals do work. I haven't prioritized troubleshooting and fixin' them yet. I'm just messing around and found something interesting a couple minutes ago...

With the headlights off, even with the keys out, when I depress the brake pedal the instrument lights come on. Hmmm. I've got a fusebox, the instrument light circuit looks to be independent, just a 2amp fuse. So which circuit has the rear running and brake lights? Any idea what could be crossed?

Full troubleshooting to come (I HATE wiring!!!) just curious if anyone had any insight.

Please, please be something simple and easy!
Darrell

Really too late for me to work on this tonight, I will give it a shot in the morning.

But start here: brake light switch wire come from fuse box, to signal switch harness after the switch.

For it to back feed> something is wired wrong.

Brake lights not working and signals are is the clue>
they both use the same wires after the signal switch
to the tail lights. So somehow the brake light wire
after the brake switch is not hooked up to the signal
harness right.

[DarrellG]

Thanks Jeff and Jim -

I'll start with your info - no worries, I'm in no hurry. I figure at least another month before she's my daily driver. Got quite a few things going at once. I try and pick one task each day and give it a few hours. I just noticed the brake/dash connection tonight so thought I'd throw it out there.

Just asking because I never know what I'll feel like doing tomorrow

Thanks guys,
Darrell

[Hotfoot]

ELECTRICAL GREMLINS! Hate the little guys!

(Thanks AMC)

I am thinking of rewiring mine with a universal kit.

you have to take the wiring diagram and track down each wire from start to finish. Something may be crossed or a connector was put in the wrong spot. Look for any telltale splices or repairs.

Good luck.

[docproc]

My 2 cents FWIW, I have on more than one occasion seen filiments in tail/brake light bulbs break and short to each other. I woud start by carefully inspecting your bulbs. Something is causing the dash lights to energize. Oh, and of course check and clean all youyr grounds and sockets. Mr. B.

[Russ]

My first thought is the standard answer for electrical problems, check your grounds. The battery should be grounded to the engine, and you should have a ground wire from the engine to the cab. Then you need a wire from cab to frame, and finally a wire from the frame to the bed. Make sure all these grounds are in place before tearing into the wiring or you may cause more problems.

[duracell]

just to say it. do you have a plug-in for a trailer? many people have had problems with the wireing for trailers messing up the truck wireing. mostly involving the brakes

[edjnsd]

Could be that somebody messed with the connections
at the Firewall of the truck. Your 65 SHOULD have
"bullet style" electrical connectors on both sides
of the rubber firewall block, if someone pulled them
then put them back in the wrong spot that could
cause problems like you described.

Also.... does your truck have a switch for
"Emergency Flashers"? those were optional, and
plugged in between the firewall block and the
dash wiring, More chances for "errors" if someone
disconnected then attempted to reconnect your
wiring.

[Jeffc]

Lot of stabbing in the dark above. Nothing wrong with that -it's worked for them- but take one thing at a time.

Grounding> since you got signals working, no big issue
here; however, all grounds should be checked, cleaned.
Just a good idea.

Sockets> yes, do check them and the bulbs, sometimes
replacing bulbs will solve things. But in this case
the signals work and brake lights don't and they
are on the same wire from the signal switch, so it
may only solve the running light issue since they have
there own wire that runs from light switch.
1157 is the correct bulb number for both front and
rear running/signal lights.

E-flashers> not on a 65 truck unless added post
factory (e-flashers were added factory 67).

Trailer/Camper plugs> Yes, check for this, splices
for these often cause problems, maybe the problem
with the running lights, but not the signal since
it works and share same wire with brake. Check and
clean up if you do find splices regardless.

Fire wall plugs> these do cause problems from time to time and should be pulled from the block and cleaned
as best as can be. Not the issue with the signal/brake
lights, but could be with running lights since
they are a diffeant wire.
Should not cause a back feed
to dash lights unless the block is melted or there wires crossed nearby.

Headlight switch> dash lights run off this (and of course the headlights/running lights) and the reostate on the front part of the switch. Orange wire
from switch to dash lights.
Signals have nothing to do with this switch <or should not have any thing to do with it>.

Signal Switch> power for switch come from fuse block
feed from flasher on block (Red 16ga wire) plugged into signal harness with same color wire and gauge.
Power only when key is on.

Brake light switch> power feed is from fuse block
(red 16ga) to peddle switch after switch wire changes
to white and is plugged into white in signal switch harness. It should have power at all times, even when
key is off.

Work though each issue, one at a time, find what
works, what doesn't.......

[Russ]

[quote="DarrellG"]I've had my '65 D200 three weeks or so, the rear running lights and brake lights don't work (yet). Rear turnsignals do work. I haven't prioritized troubleshooting and fixin' them yet. I'm just messing around and found something interesting a couple minutes ago...

With the headlights off, even with the keys out, when I depress the brake pedal the instrument lights come on. Hmmm. I've got a fusebox, the instrument light circuit looks to be independent, just a 2amp fuse. So which circuit has the rear running and brake lights? Any idea what could be crossed?

Full troubleshooting to come (I HATE wiring!!!) just curious if anyone had any insight.

Please, please be something simple and easy!



"Lot of stabbing in the dark above. Nothing wrong with that -it's worked for them- but take one thing at a time." Quote: Jeffc

Jeffc, I wasn't stabbing in the dark when I suggested checking the condition of the grounds. I was trying to prevent him from causing more problems. I've had many old cars and trucks and I've found that most of the electrical problems I've had were caused by previous owners fooling with the wiring.
I think that the bed not being grounded can cause the symptoms he's having. In an 1157 bulb one side of the filaments are tied together. That side should be grounded through the outer case of the bulb. If you have no ground and apply voltage to the brake light filament current will pass through both filaments and find a path back to a ground through other running light bulbs, and dash light bulbs, which are all tied together and grounded. The dash lights will probably light because they are the smallest and light with the least current.
He says the turn signals work, but I suspect that if he checks closly he will find that the running filament is flashing, not the brake filament. The brake light filament is by far larger than the running light filament so the thinner filament will light.

He might have some other issues, possibly a bad brake light switch, but I stick to my suggestion that the bed needs to be grounded. Also, if it's a wide bed the tail light buckets must also have a good ground through the mounting screws.

Actually, neither I nor anyone else has mentioned the most logical first step in analyzing this problem. He says the rear tail lights, or running lights don't burn. He should just remove the lense and bulb, turn on the lights, and check for voltage at the bulb socket. If there's voltage there then it's either the socket, bulb, or no ground. If no voltage, then look for a wiring problem. I think I could have fixed the problem in less time than it took me to type this, LOL.

[Jeffc]

good luck with that Russ
No disrespect intended
lets see what he comes up with and take
it from there

[DarrellG]

Man Russ or Jeff - to quote Floyd ---

"I wish you were here!"

Spent the morning with the wiring. New bulbs and cleaned sockets was two weeks ago - today, pulled both housings. I got rid of an ugly trailer splice in the left line. I removed the junk section and soldered and shrunk wrapped the connection. From the junctions back it's clean, It should be all good. No go yet though...

Can't tell if the dash lights still light with the brakes yet - it's too bright outside.

I'm sick of it today, I thought getting rid of the splice junk was gonna work :(

Thanks for the help guys - I've now got too much info to wrap my head around (yea, that's possible!) I'm just not really good at wiring. I'll continue with the basics tomorrow, maybe. Maybe I'll tackle something else.

Thanks all for the time! - I'll find out what's up eventually. What the heck, the more I have to dig into, the more I learn!

Darrell

[Jeffc]

So, so you think you can tell heaven from hell, blue skies from pain
Can you tell a green field from a cold steel rain? A smile from a vein,
Do you think you can tell?

And did they get you to trade your heroes for ghosts? Hot ashes for trees?
Hot air for a cool breeze? Cold comfort for change?
And did you exchange a walk on part in the war for a lead-role in a cage?

How I wish, How I wish you were here.
We're just two lost soles, swimming in a fish bowl, year after year
Turning over the same old ground. What have we found? The same old
fears,
Wish you were here.
(PF)

Yes, I'm a fan.....
How can you have any pudding if you don't eat your meat!!!!

[65Dodge100]

Yes, I'm a fan.....
How can you have any pudding if you don't eat your meat!!!!

Welcome my son,
Welcome to the machine

[Russ]

At least a Sweptline owner isn't just another brick ....