73 Multiple Headlight Switches Bad
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
Likes: 79
From: Northeast PA
73 Multiple Headlight Switches Bad
Curious if anyone’s experienced issue with failing headlight switch replacements where the two I’ve received only work the headlights, no parking/marker/dash instrument lights… if I jump power at the H/L switch connector all the lights work so fuses & wires are ok. Weird that both replacements do the same exact thing, one was from Top Flight & 2nd from Lectric (whom I hold in very high regard). The actual switch has 8 terminals but the original had 7. Checked switch continuity & that verifies it’s actual operation of only headlights. I trashed the original so can’t directly compare… ordered another that appears to have only the 7 terminals… am I crazy or just missing something obvious?
Pro
Joined: Nov 2019
Posts: 648
Likes: 353
From: Portland, Oregon
Mine didn’t work right until I changed the dimmer switch as well. Headlight switch came from Doc R., but I hate dealing with him. Was $75 and he claimed it was closer in quality to the original than available elsewhere. Dimmer switch came from Rock A.
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
Likes: 79
From: Northeast PA
That’s interesting, thanks… although that doesn’t seem like it could be the cause, as the power is supplied to dimmer switch by the blue wire from H/L switch, which then would divey up the power to the appropriate H/L mode. I received another switch today, which had the 7 terminals but was completely smashed to pieces on arrival. I’ll check the dimmer switch anyway but have doubts that this item would have such an impact. Are these that delicate that any minor bump would render them useless? I did drop the box that the Lectric switch was in before I put that in so it’s feasible that act mucked it up.
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I doubt that dropping the box did anything. Im surprised the LectricLimited switch is bad as well. THe symptoms you have I had as well. Check your fuses at the fuse panel and check the continuity through the fuse panel as well. My panel had rotted the connectors behind it and I lost everything ecept my headlights. I did a lot of tracing and the brakek lights, dashlights and running lights all run through the same wiring. On my 68 the power comes through the light switch down to the fuse block and back again. Thne onto the dash and rear.
Good luck. I had to do alot of probing and tracing to figure my issue out
Good luck. I had to do alot of probing and tracing to figure my issue out
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
Likes: 79
From: Northeast PA
Thanks, really appreciate your responding! My situation is when I put 12V to either of the appropriate terminals at the headlight switch connector, those associated lights work… I have a Power Probe, & putting power to the green wire terminal lights up the instrument lights, on the brown it lights the parking/markers, blue fires the headlights. In a 73, power for all that comes from that one feed from battery, & the H/L Switch distributes the power based on the ****’s position. That said, it confirms wiring, fuses, powers & grounds are good,.. that only leaves the switch itself, in my feeble mind, anyway.
Is my vette stock?? HAHA
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do you have a meter so you can check continuity through the switch?
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
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From: Northeast PA
Yep, already did that & no continuity from power to inst lites, or markers, with the **** pulled to half or full way out. Headlites were intermittent. That was consistent with my doing the bypass switch routine…
Is my vette stock?? HAHA
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with the switch out of the circuit, does it test bad, is my question. Can you just test terminal to terminal. That would point to this switch and nothing else
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Thread Starter
Racer
Joined: Jun 2017
Posts: 401
Likes: 79
From: Northeast PA
It does, no continuity to any other outgoing terminal except headlight intermittently… but the thing is, the prior switch that I bought from Top Filght at Carlisle tests the same way… that’s what bugs me, it’s too coincidental.
Team Owner
Joined: Mar 2002
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From: Huntsville AL
I'm not buying all these bad switches, something doesn't pass the sniff test. Your troubleshooting is good and appears to tell the story, it would be nice to have the original SW for additional testing.
My brain would start to question if the "new" switches were in fact correct for a 73. You stated the new switch has 8 terminals but the original only had 7, what's this #8 terminal for?
My brain would start to question if the "new" switches were in fact correct for a 73. You stated the new switch has 8 terminals but the original only had 7, what's this #8 terminal for?
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
Likes: 79
From: Northeast PA
I don't know what that 8th terminal is for, there's a place in the connector where it fits, without an associated wire & connector terminal. The DOA switch that I last received had only 7 terminals & (since it was already in pieces) I compared to the original GM switch & inside it looked the same. I did just have another thought after looking at the wiring diagram, where the parking/marker lights are independently powered from the fuse box on the orange wire which appears to supply power to the brown/park/marker wires, so there wouldn't be continuity between the red/batt power & the brown wire... It just may be me, I'll update after checking that fuse...
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
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From: Northeast PA
Mental update... I just re-studied the H/L switch positions & wiring, & believe the issue was my stupidity after all... checked continuity to the terminals differently now that I better understand the functions, & switch seems to demonstrate that correctly. I theorize that it was the taillight fuse all along, which I will verify tonight or tomorrow & subsequently update...
Is my vette stock?? HAHA
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Hope thats it, eletrical problems are a hassle.
Good luck!!
Good luck!!
Thread Starter
Racer
Joined: Jun 2017
Posts: 401
Likes: 79
From: Northeast PA
Solved… my stupidity, parking/tail lights’ power comes FROM the fuse box separate from the batt wire, bad assumption on my part. Low & behold, the tail lite fuse was blown & replacing it made it all better.
Hopefully someone else will benefit from my discovery & save hours of frustration… carefully read the wire diagram & it will set you straight!
Now, anyone have a picture or easy description of which vacuum lines go thru the two firewall grommets, still seems hard to get a pic that shows the source & destination routing of these…
Hopefully someone else will benefit from my discovery & save hours of frustration… carefully read the wire diagram & it will set you straight!
Now, anyone have a picture or easy description of which vacuum lines go thru the two firewall grommets, still seems hard to get a pic that shows the source & destination routing of these…