1966 Plymouth Barracuda Formula S - Restoration
I know yall are probably getting tired of text only posts, but the latest update - I had to drill out the main A1 voltage post. There was no removing it, both sides were melted. I ended up adding a new fusible link and just bypassing the bulkhead connector and drilling it out. I tinned all of the crimps and connectors, used lineman splices, soldered the splices, and covered everything with 3 sizes of heatshrink tubing. The old line had at least 2 spots where the insulation was bad - one rubbed all the way through (probably the one that caused the short) and another spot that was almost all the way through. I only cut the ends - wasn't worth removing all of the wire wrap. Maybe someday I'll replace the entire harness, but for now I'm trying to get everything in good shape from a wiring and mechanical perspective and from a resistance perspective, it looks to be serviceable, given the other issues I've found.
If you're looking for a great guide on splicing, soldering, joints -
https://standards.nasa.gov/file/2615/download?token=2TwNY-Aq .. it's the NASA workmanship standard for wiring. Lots of good information - and if you're tired, it's great bedtime reading material. Either way, I've learned a lot from it over the years.
I traced through the rest of the electrical issues tonight. It didn't take that long to go through the issues and nail down causes - spent about 2 hours tonight in the garage. The list - as follows.
The temp and oil sender are both completely wrong - they're both for an idiot light, not a gauge, so that's the reason they're not working. Rang them out with an ohmmeter and discovered they're both reading way too high for a gauge application. I ordered new senders for both (for a gauge, not a light). From an engineering perspective it's really frustrating that it's not easy to get datasheets for senders, switches, etc. I fully understand why someone probably installed the wrong ones, trying to get the gauges working. The in-gauge voltage regulator was shot - so without ohming out a sender and knowing what the resistance
should be, its an easy mistake. That said - with both the temp and oil senders being new, that should have been a clue. I spent more time than I'd care trying to find resistance specs on the temp and oil pressure senders, with little luck - what I did find mostly came from forum posts and educated guesses. I ordered a SMP TS-17 for the temp sender and a SMP PS-59 oil pressure sender. They both appear to be for gauges, not lights - and hopefully they're within the resistance specs. I plan on measuring both when they get here and posting results so at least this post will come up if someone searches the same parts.
The instrument lights not working - the headlight switch needs either refurbished or replaced. It gets up to about 5-6 volts before cutting out completely on the dimmer. They're kind of readable at 5-6 volts, but .... might as well fix it. I'll pull it once the new tach comes in and take a look at it when I have more room to work.
I rewired one of the rear light sockets - the single post bulb contact was basically snapped off - used lineman splices and soldered/heatshrinked it. Rear lights are all working again.
The drivers side fender mounted turn indicator - the mechanical switch on the column is all loosey goosey. I pulled off the broken cam and tested it .. I got it mostly working with a couple of real thin plastic shims, but everything is flexing too much to try to rely on it lasting. The cam had the mopar stamp, so I'm assuming it's original. I ordered a new one from old car parts NW (which I assume to be affiliated with slantsixdan). Either way, his posts and knowledge have been super helpful over the years, especially with my first 64 Barracuda.
The horn issue - the column/shaft has no ground. Fixable, but I'm not entirely sure where the original grounding would have come from. It looks like the shaft/column should have been grounded fine through the steering box and the under dash support that holds the column up. Does anyone know where the original grounding should have come from? The column is insulated with a rubber sleeve at the dash, but it really seems like the steering shaft should have served as ground. At there's no rag joint to have to jumper like in my 66 F100.
I'm starting to feel like I have a boat (break out another thousand). But at least it's not that bad yet and electrical is my forte. After the electrical is completely sorted, I need to sort out the clutch. I kind of suspect it has a 3 prong pressure plate thats worn, or the return spring is just completely shot. I can't imagine it's the huge under dash pedal arm spring. It's engaging/disengaging over most of the travel of the clutch pedal and sticking to the floor pretty regularly. Before I dig in - ideas are welcome. Thanks for reading!