***Warning...longwinded post about electrical follows***
Ok gents, I'm a pretty patient, smart (maybe, although I do fly a pretty complex machine), and meticulous person, but I'm starting to get stumped on this one...primarily because of the "PO wiring mod." My truck is 6/72 with a 1970 350 conversion....So here's the back story:
I decided I wanted to replace all my rear brake lights (so they would match), back up light, and markers with new OEM units. Easy day right? Ok, so I remove the old ones, scuff up all the grounds so they're nice and clean, then replace them. I check the operation of each thing as I'm replacing and they're all working. So far I had replaced both tail lights, the back up light, and the rear side marker lights. Everything worked as advertised. Well I start looking at the rear loom and the PO had hacked in a trailer harness (which didn't work). So I rewired the rear loom per Coolerman's "cleaned up" diagram (thanks dude!). Pretty simple. Got her buttoned up, yep...everything still works. Feeling pretty good so I go grab the wifey so she can admire my handywork. She comes out. Everything works. Wife clearly in awestruck state...
Fast forward 30 mins . I come back and just for grins I want to see it work. Everything on the rear works, but now the headlights wont work. Hmm. I check a few things including the headlight switch (cleaned and reassembled) and now I have no brake lights, but I have headlights. I try the hazards. I have hazards, but after turning them off I have no turn signals and no brake lights. It progressively got worse until the only thing that would work consistently was the headlights and occasionally the turn signals. I never could find a pattern of turning things on and off that resulted in them working consistenly. Using a test circuit I energized the tail loom and it all works correctly (I knew this already since I had seen it with my own two eyeballs). I check the grounds and they were good. Reground the battery, etc.
Bottom line I'm not getting power to the rear brake lights via the solid green wire. So I check the brake switch...aha!
One of the connectors is broken off. Ok, so that's got to be the problem right? Well, I hold the broken connector back on, depress the brakes, and still nothing (though now that I think about it seeing the picture that corrosion is pretty bad, probably should scuff it up). I've got a new stop light switch on order. Continuing my troubleshooting I pop the instrument panel and notice there's some serious chaffing on the main loom. I peel it back and this is what I found:
So, a really chaffed Black/White (starter circuit), and 3 parted wires: black, black yellow (oil pressure sender???), blue yellow (????).
And finally it looks like someone hacked in a cluster bulb (this doesn't look like a factory splice):
This dang bulb lights up anytime the key is in the acc or ign position (it's always on while driving...hence, someone put black electrical tape over it). Its wire runs out the firewall next to the clutch master cylinder and is grounded somewhere in the engine bay.
One other thing to note is there was a single pole, double throw switch (on/off) that was wired in coming from the turn signal, through the switch, then back into the turn signal loom (above the switch there's a sticker that's been painted over that says <Tow----Drive>. I eliminated this switch (since I got rid of the trailer harness). I don't think this has anything to do with anything since everything worked after removing the switch.
So here's my questions:
1) Am I barking up the right tree as far as troubleshooting. Is the stop light switch the key?
2) Obviously I need to fix the chaffed wires, but what do they go to exactly (I took a WAG at it).
3) Any ideas as to what that light is? (I thought it was the hi/lo for the headlights, but that doesn't seem to be it).
I'm open for comments, criticism, whatever as I'm completely stumped right now. I've troubleshot everything I can think. Stared at wiring diagrams forever, and just wanted to see if anyone has had a similar experience. I'm located in San Diego if anyone can offer some help.
Ok gents, I'm a pretty patient, smart (maybe, although I do fly a pretty complex machine), and meticulous person, but I'm starting to get stumped on this one...primarily because of the "PO wiring mod." My truck is 6/72 with a 1970 350 conversion....So here's the back story:
I decided I wanted to replace all my rear brake lights (so they would match), back up light, and markers with new OEM units. Easy day right? Ok, so I remove the old ones, scuff up all the grounds so they're nice and clean, then replace them. I check the operation of each thing as I'm replacing and they're all working. So far I had replaced both tail lights, the back up light, and the rear side marker lights. Everything worked as advertised. Well I start looking at the rear loom and the PO had hacked in a trailer harness (which didn't work). So I rewired the rear loom per Coolerman's "cleaned up" diagram (thanks dude!). Pretty simple. Got her buttoned up, yep...everything still works. Feeling pretty good so I go grab the wifey so she can admire my handywork. She comes out. Everything works. Wife clearly in awestruck state...
Fast forward 30 mins . I come back and just for grins I want to see it work. Everything on the rear works, but now the headlights wont work. Hmm. I check a few things including the headlight switch (cleaned and reassembled) and now I have no brake lights, but I have headlights. I try the hazards. I have hazards, but after turning them off I have no turn signals and no brake lights. It progressively got worse until the only thing that would work consistently was the headlights and occasionally the turn signals. I never could find a pattern of turning things on and off that resulted in them working consistenly. Using a test circuit I energized the tail loom and it all works correctly (I knew this already since I had seen it with my own two eyeballs). I check the grounds and they were good. Reground the battery, etc.
Bottom line I'm not getting power to the rear brake lights via the solid green wire. So I check the brake switch...aha!
One of the connectors is broken off. Ok, so that's got to be the problem right? Well, I hold the broken connector back on, depress the brakes, and still nothing (though now that I think about it seeing the picture that corrosion is pretty bad, probably should scuff it up). I've got a new stop light switch on order. Continuing my troubleshooting I pop the instrument panel and notice there's some serious chaffing on the main loom. I peel it back and this is what I found:
So, a really chaffed Black/White (starter circuit), and 3 parted wires: black, black yellow (oil pressure sender???), blue yellow (????).
And finally it looks like someone hacked in a cluster bulb (this doesn't look like a factory splice):
This dang bulb lights up anytime the key is in the acc or ign position (it's always on while driving...hence, someone put black electrical tape over it). Its wire runs out the firewall next to the clutch master cylinder and is grounded somewhere in the engine bay.
One other thing to note is there was a single pole, double throw switch (on/off) that was wired in coming from the turn signal, through the switch, then back into the turn signal loom (above the switch there's a sticker that's been painted over that says <Tow----Drive>. I eliminated this switch (since I got rid of the trailer harness). I don't think this has anything to do with anything since everything worked after removing the switch.
So here's my questions:
1) Am I barking up the right tree as far as troubleshooting. Is the stop light switch the key?
2) Obviously I need to fix the chaffed wires, but what do they go to exactly (I took a WAG at it).
3) Any ideas as to what that light is? (I thought it was the hi/lo for the headlights, but that doesn't seem to be it).
I'm open for comments, criticism, whatever as I'm completely stumped right now. I've troubleshot everything I can think. Stared at wiring diagrams forever, and just wanted to see if anyone has had a similar experience. I'm located in San Diego if anyone can offer some help.
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