Headlight switch drama

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Dart5150

Dart5150

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I'm getting my a&& handed to me by an electrical issue, and I suspect that there is one company making these switches overseas under multiple names/packaging, and they're all defective.

1964 Dart GT. The issue has been no rear running lights, brake lights, or dash lights. Headlights and turn signals are okay. Pulled the switch from the dash and tested it with the meter with it installed - switch is bad and not sending power to those terminals. Bought a replacement from O'Reilly's, Standard Parts part # DS 165. Installed it and it worked for about a month before it failed, same exact issues. Tested it and confirmed it's bad. Bought another Standard Parts part # DS 165 and replaced it. Worked for about one minute, then gone. Removed it and bench tested it, bad switch. Bought a third Standard Parts part # DS 165, and it worked for a few days before going out. I took the car to an experienced local mechanic that I know well and he tested the circuits and said we aren't having a grounding issue. He went through it a second time to be sure, no issues found. So I went over to O'Reilley's again and bought Standard Parts part # DS 165 number four. This time we tested it right out of the box before installing - bad switch. All of these boxes say 'Made in Taiwan', and all fail with the same symptoms - headlights work but the taillights, brake lights, and dash lights do not.

So we install this defective switch with jumpers from the headlight terminal to the brake, tail, and dash terminals. As long as you drive the car with the headlights on, everything works and it's not blowing fuses.

At this point I'm done with O'Reilly's and Standard Parts brand, although I'll give O'Reilly's credit for warrantying all of them. So I call NAPA. They have an Echlin brand switch, part # HL6571. I've always had good results with NAPA/Echlin ignition parts, so I had them order it in for me. Went to NAPA when it arrived - box says made in Taiwan. Eye roll and groan. Install it, and it works for a moment and goes out. Bench tested switch number 5 and it's no good. So this time I decide to drill out the three rivets and take a look at the inside of the switch. There is no sign of mechanical or electrical distress. In fact, they appear to be fairly simple and solid.

I'm at a loss here. The mechanic is adamant that there isn't a short, and the fact that everything works with the jumpers in place with the headlights on without blowing a fuse seems to back this up. As does the fact that one was defective out of the box, without being installed.

Any thoughts? Am I missing something? Has anybody seen multiple failures like this on other parts?

SW2.jpg


SW1.jpg
 
I would suspect you are making a l mistake somehow. You are aware? That the tail /park circuit gets power from a separate source. B1 /B2 both must be receiving power. Check it under load. Install it loose, hanging down so you can access the terminals. Pull on park. Check that B1 and B2 are both hot and whether the tail and park are also hot.

If not, and they actually really are defective, I don't know what to say. Round up a used one, and install two relays, one for high, one for low beam.
 
67Dart273 said:
I would suspect you are making a l mistake somehow. You are aware? That the tail /park circuit gets power from a separate source. B1 /B2 both must be receiving power. Check it under load. Install it loose, hanging down so you can access the terminals. Pull on park. Check that B1 and B2 are both hot and whether the tail and park are also hot.

If not, and they actually really are defective, I don't know what to say. Round up a used one, and install two relays, one for high, one for low beam.
67Dart273 said:
I would suspect you are making a l mistake somehow. You are aware? That the tail /park circuit gets power from a separate source. B1 /B2 both must be receiving power. Check it under load. Install it loose, hanging down so you can access the terminals. Pull on park. Check that B1 and B2 are both hot and whether the tail and park are also hot.

If not, and they actually really are defective, I don't know what to say. Round up a used one, and install two relays, one for high, one for low beam.
Click to expand...
Click to expand...
Can I trouble you for clarification on power to B1 and B2? My wiring diagram shows a black wire from the ammeter going to B1, which I assumed was incoming power. It shows two wires on the B2 terminal, one going to the stop light switch and the other to dome light. My assumption was that power to the brake light switch was supplied from the B2 terminal.
 
if you are on the right terminals checking for continuity with the switch in the right positions it's just either good or bad. All of the switches normally open or normally closed contacts don't care what is going on with the rest of the car. Past that with the switch in the car is where the gremlins come in. I will leave it at that and let the real pros help you trace it down. I was looking for an original switch for one of my cars so I will pass the ad on to you. Not knocking any mechanics but maybe get a second opinion on whats going on with the switch hanging in free air to make it easy to check. No fuse blowing?
 
Not to muddy things up but on my 68 B the parking lights go out when I turn on the headlamps by design. I also have a 64 A and I replaced the H/L switch as they cut out driving at night.....turned out to be the connection at the floor dimmer switch which h/l juice goes through. All cruddy and corroded . Anyway the SMP h/l switch dash dimmer was very hard to turn and the dash lights were off. I was afraid to turn it the knob that hard for fear of breaking it but it's works fine now . I nterior lights now turn on with an audible click. Have you looked at the directional switch? Rear stuff goes through that too I believe.
 
67Dart273 said:
I would suspect you are making a l mistake somehow. You are aware? That the tail /park circuit gets power from a separate source. B1 /B2 both must be receiving power. Check it under load. Install it loose, hanging down so you can access the terminals. Pull on park. Check that B1 and B2 are both hot and whether the tail and park are also hot.

If not, and they actually really are defective, I don't know what to say. Round up a used one, and install two relays, one for high, one for low beam.
Click to expand...
67Dart273 You were right, there is a second 12v supply. After looking more closely at the wiring diagram, the brake light switch has two wires on one of the connectors, one of which is hot and coming from the fuse block, and the other goes to the B2 terminal on the light switch. So this is why there is supposed to be 12v at B2 as well as B1. I was assuming that there was a single power supply at B1. Makes sense that the tail lights would be on a different feed. So now I need to trace that wire on the brake switch back to see why I'm not getting 12v from the fuse block.
Thanks for pointing me in the right direction. I had a major Mopar rookie brain fart there. :lol:
 
66Valiant528 said:
Not to muddy things up but on my 68 B the parking lights go out when I turn on the headlamps by design. I also have a 64 A and I replaced the H/L switch as they cut out driving at night.....turned out to be the connection at the floor dimmer switch which h/l juice goes through. All cruddy and corroded . Anyway the SMP h/l switch dash dimmer was very hard to turn and the dash lights were off. I was afraid to turn it the knob that hard for fear of breaking it but it's works fine now . I nterior lights now turn on with an audible click. Have you looked at the directional switch? Rear stuff goes through that too I believe.
Click to expand...
See my reply above to 67Dart273. He pointed me in the right direction with 12v being present at B1 and B2. Regarding the parking lights, I've noticed that when I pull the headlight switch to the first position (headlights off, parking lights on), all four lights are lit up. But when I pull it out to bring on the headlights, the front parking lights go off while the rear parking lights remain lit. I assume that this is normal, and that maybe the DOT mandated they stay on with the headlights sometime after 1964. Seems like I saw or heard that somewhere.
 
Dart5150 said:
See my reply above to 67Dart273. He pointed me in the right direction with 12v being present at B1 and B2. Regarding the parking lights, I've noticed that when I pull the headlight switch to the first position (headlights off, parking lights on), all four lights are lit up. But when I pull it out to bring on the headlights, the front parking lights go off while the rear parking lights remain lit. I assume that this is normal, and that maybe the DOT mandated they stay on with the headlights sometime after 1964. Seems like I saw or heard that somewhere.
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Off when headlights on is correct
 
Dart5150 said:
when I pull it out to bring on the headlights, the front parking lights go off while the rear parking lights remain lit. I assume that this is normal
Click to expand...

Yes, until Federal Motor Vehicle Safety Standard 108 took effect on 1/1/68, then the parkers had to stay on with the headlamps so oncoming drivers could still see the width of your car after a headlamp burnout at night.

Dart5150 said:
and that maybe the DOT mandated they stay on with the headlights sometime after 1964. Seems like I saw or heard that somewhere.
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It was here (or one of the other times I posted it), along with E-Z instructions on how to do the safety upgrade.

(Also, Standard Motor Products bought Echlin, BWD, and Niehoff from Dana in 2003)
 
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