65 Dart. Brake lights and dome light stay ON....Why ??

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Kern Dog

Build your car to handle.
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I am just getting this old neglected beater running.
1965 Dart, originally a slanty but when I got it in 2015, it had a 318, a slip yoke 904 and a few hokey "changes". I have erased some of the crimes and got the thing up and running. The dome light and brake lights seem to stay on all the time though. The brake light switch is in place and the slide does move. The horn wanted to stay on so I pulled the wires from the horns until I can diagnose that.
This is odd...Most cars I buy to fix up have no horn, no dome light, no taillights either!
What may be causing this? I am still learning how to work on electrical stuff so any help is appreciated!
 
See, that is what confuses me...I would expect a bad ground to cause a light to NOT work.
 
I am no expert but grounding (not grounding) will find its way through other circuits and activate them seeking a ground unnecessary in that circuit
 
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Get out of your head that electricity flows from positive to negative. Electricity does what it wants to do.



We just give it direction
 
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For some reason, I was expecting there to be a relay to blame.
 
Well, there are several differences between the early A and the 67-76 models. I have worked on the later A cars since 1983. There is a relay on this car near the master cylinder, one that I have not seen on other cars. In my 70 Charger, there are a few under the dash.
Again, I am not that skilled regarding electrical stuff. I do pretty much everything else!
 
Thanks, Dave. I am pretty familiar with what it takes to make the cars start and run, I am a little fuzzy on the interior wiring, dash and HVAC stuff too.
I had an 84 Chevy truck that did odd stuff sometimes. The wipers woud sometimes not want to shut off. The dome light would stop working when the horn relay burned out. The ALT/BATT light came on sometimes if the oil pressure was low, even at freeway speeds. Strange, huh?
 
Brake light and horn problems at the same time? I would suspect the turn signal switch! Wiring for them goes through It. Dome light wiring goes through the Headlight switch AND the brake light switch. I would suspect the brake light switch or possibly one of the door switches where the wires are touching. If you need a turn signal switch SlantSixDan had a run of exact reproductions made; contact him and see if he has any left (I bought 3 of them!). Good luck and let us know what you find.
 
Check that power goes in and not out till the switch is engaged by the pedal. If it's constant hot at both sides..the switch is bad.
The dome light could be the jamb switch.
You would have running lights only if the turn switch wasn't working, could be stuck on with it working incorrectly. How's the headlight switch? Have you checked it, volt meter to see if it's switching correctly.
The horn has a hot lead...grounds to activate. I had a rim blow horn stay on...the ground wire insulation was worn. Check the one ground wire for the horn, under the horn ring.pop it off.
 
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Back feeding through pinched, melted, or crushed wires can cause that.

Might consider pulling fuses one at a time till they go out. If one fuse kills both you'll know electrical incest is at work, if pulling one fuse kills one light but the other remains, then you likely have two separate issues.

Pay attention to the fuse you pull, then follow those wires from fuse box on the wiring diagram (you DO have a diagram, right? ) to get a head start on where you're hunting.

Always pull, clean, grease, and preferably bypass the bulkhead wiring.

My car did similar stuff. Found melted brake light wires caused by **** bulkhead connector, they weren't using protection and spreading electron vd everywhere. Pretty gross.
 
Disconnect one wire at the brake light switch.........see if the brake lights go out. Likely bad brake light switch. If not trouble in the wiring harness

Dome......START WITH checking the bulb number. It's listed in the service manual. My 67 uses a dual contact bulb, 1004 I believe. THIS BULB is NOT GROUNDED. The shell does not ground the bulb

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The dome lights are turned on by grounding the switching wire, that is the functional circuit path is this..........

From a hot feed in the fuse panel..........through the fuse.......power up to one side of the dome light bulb WHICH IS NOT GROUNDED.......the grounding/ switching wire comes down........goes to door switches.......AND BRANCHES OFF ........also to the light switch. Twisting the knob turns it on so check that FIRST.

Then remove the door switches and pull them out far enough you can "clear" the wires. If it still lights, that switching wire is grounded somewhere. START AT the dome socket,

Scientists, technicians, and would be ignore list members: Please do not argue with me about the "functional circuit path." I'm merely following the "road map" down the path that the thing takes. I AM NOT REFERRING TO ELECTRON FLOW OR OTHER points of non-interest
 
Back feeding through pinched, melted, or crushed wires can cause that.

Might consider pulling fuses one at a time till they go out. If one fuse kills both you'll know electrical incest is at work, if pulling one fuse kills one light but the other remains, then you likely have two separate issues.

Pay attention to the fuse you pull, then follow those wires from fuse box on the wiring diagram (you DO have a diagram, right? ) to get a head start on where you're hunting.

Always pull, clean, grease, and preferably bypass the bulkhead wiring.

My car did similar stuff. Found melted brake light wires caused by **** bulkhead connector, they weren't using protection and spreading electron vd everywhere. Pretty gross.
Electrical incest:lol:
 
See, that is what confuses me...I would expect a bad ground to cause a light to NOT work.
Kern if I've learnded anything it's that bad grounds cause weird crap! My first step would be to follow the circuit towards the fuse, could be the last guy monkeyed with it and switched a wire, bypassing the switches...look for obvious signs of phuckery like electrical tape, plastic wire nuts etc...
 
....Signs of fuckery....
Funny. I've heard many terms used to describe poor/cheap work. Thats a NEW one.
 
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