69 Charger. Started running a bit rough two weeks ago, thought I picked up some debris in the carb, cleaned it out, no better. Went to a friends mopar party last Saturday (150 miles round trip). On the trip home we pulled onto the highway to cruising speed, 70, wife said she thought she could smell something burning (electrical), I started feeling the dash wiring harness, seemed ok, smell went away, after five miles on the highway the car shut off, lost all power, coasted to a stop in the BD lane .
Battery connections fine, started wiggling the two bottom wires on the starter relay and the interior lights came back on, car started back up, fuel, oil pressure and temp gauge now not working. Took off, stayed in the right lane just incase, 30 miles later died again, coasted into a rest stop, wiggled the two bottom wires on starter relay, lights came back on in car, shut hood, started car and took off (darkness now setting in), left turn signal now not working. 10 miles later it died again, this time wiggling the two bottom wires did nothing, when I started wiggling the fusible link wire at the BH connector the interior lights came back on. At this point the remaining 25 miles home seemed like a longshot. Made it 15 miles to my Dad's house, parked the Charger and borrowed his car for the rest of the ride.

On Sunday I decided to play it safe and trailered the car home. Two bulbs burned out on DS tail lights. Can't get the gauges to work, think the voltage limiter on the back side of dash is fried. I wiggled and yanked on the starter relay wires to no avail to try and get the interior lights to shut off. All the fuses are ok. I replaced ALL the wiring harnesses when I rebuilt the car a few years ago so [censored] like this wouldn't happen. Have already had to fix a loose connection in the fuse box this year. Think the starter relay is one of the few things I didn't replace when I restored car. Can they start working intermittently or cause a voltage spike that could fry bulbs and my voltage limiter? What else might be causing this issue?

As you know from wiggling the wiring near the Fusible link and the fusible link that the link is probably burnt. Replace it and see if you still have problems.



This makes me nervous. The last time I had lights not be able to be turned off the under dash harness had started to burn and wires were shorted.

Replace the Fusible link and see where you stand. Disconnect the light switch and if you still have lights on there is a short.

Also start pulling fuses to see if the lights go out. let us know which fuse it is.

Bet the alternator full fielded on you.

Measure the battery voltage with the engine running.

Let me clarify. I had my driver side door open when I was working on the car on the side of the road so I would know if the power came back on. In my shop tonight I had the DS door open and was wiggling the wires to if I could get the power to turn back off. Trying to re-create the issue to pinpoint the problem. Sorry if I wasn't clear on this in my original post.

X 10 and proceed with caution as something is definitely amiss. I would not drive the car or leave the battery connected until the root cause is found.

Keep us posted

I had a strange one 30 or so years back that pretty much fried the fuse box and dome light harness. The previous owner had put a single contact bulb in the dome light which requires a single filament TWO contact bulb. It would intermittently short to two contacts together resulting in an intermittent dead short.

Also while looking around, look for signs of melted wires or harness tape as usually, the closer one gets to a short the hotter the wiring gets.

Okay Now I understand.

I think your fusible link may be frying. They will look good, but be bad. Flex and pull on it. If it crunches, stretches, feels crispy etc. its is bad. They are wires in a high temperature jacket that will burn inside but not burn through the jacket and are basically a slow blow fuse.

Two other people made good points. It may be an alternator problem since the only fuse in the circuit for both the main power and field wires. And if you are unsure as to where the problem is then you should not leave the battery hooked up.

I have used fuses and, even better, circuit breakers in place of the fusible link while diagnosing wiring problems. A Fuse or circuit breaker is quicker to burn/trip but cheaper to replace. After you get the problem resolved you can put a fusible link back in. If you are not interested in OEM appearance Napa sells fusible link by the roll that is a lot cheaper than the small pieces most places sell.

As for the wiring problem check the backside of the fuse block and the bulkhead connectors for scorching/bad wiring. It is real easy for the connectors to start to come loose but that doesn't usually leave a burning smell.

In my experience the fusible link either works or its blown. If the car is completely dead, that's the first place to look, assuming you haven't altered the wiring from factory. It seems you have a short to ground on the "alternator side" of the fusible link, otherwise I think the fusible link would have burnt up. I'd unplug the connectors at the bulkhead and then plug em in one at a time and see if the short comes back. You've at least narrowed it down some that way

Don't forget to check the amp gauge wires.

Thanks for all the feedback. First of all- ALL my antique cars have battery disconnects. The only one that doesn't get disconnected everytime it gets parked is our 88 RamCharger since my wife drives it in the summer and she's too short to raise and lower the hood unless she's on a step ladder.

I tested the battery tonight. 12.75 sitting with engine off, 14.6-14.8 running at varying rpm's.
I fiddled with the wiring again. I can make the power turn off and on by pushing and pulling on the fusible link where it connects to BH connector block. As I mentioned above all new wiring harnesses from YO.
I stopped by my buddies garage on way home from work, he's a mopar guru in this area. He agree's it seems like a possible power surge, suggested I pull the alternator and get it tested. When I pull the instrument cluster to replace the voltage limiter I will check all wiring and connections. Couldn't find any wires in engine bay that looked burnt or crispy. Still need to spend some time in engine bay checking connections.

Quote

I can make the power turn off and on by pushing and pulling on the fusible link where it connects to BH connector block

that's a good start. Could just be a bad crimp or as mentioned burnt inside. Could be cooked due to a bad crimp. Whatever the problem(s) are, step # 1 is the get that fixed. But it does not explain the other issues.. The suggestion to use a circuit breaker or fuses a good one as it should prevent the car from burning up.

If this is just a loose terminal.....

The terminals are supposed to lock into the housings. Disconnect the bulk connector and look at the terminals inside the connectors. It's a little harder on the female terminal because it is buried behind the fuse block.

If the terminals are not all the way into the connector try to pull them out and expand the locking tabs. The locking tab on the male is that weird hook area between the tip and the crimp below the circle on the tip. I will expand them a little extra whenever I build a harness to make sure they lock into the connector.