HELP! 68 GTX Broke Down on the way to Power Tour

Well here's the update. THe good part is that we got it running and are currently in Salem IL for the night, about 11 hours of driving left to get to Arlington TX. We jumped it this morning at the gas station, then drove to an AutoZone to rewire what we had found through the wiring diagrams.

Battery was junk (under warranty at AZ), voltage regulator did not have a good enough ground, bulkhead connector and two wires were melted pretty bad, fusible link was bad (not burnt in two though), one ammeter stud was super loose, etc... The wires that were burnt up had significant corrosion on them, indicating that this has probably been in process for a while.

All in all, we spent about 5 hours in the AZ parking lot bypassing bulkhead, rewiring different sections, bypassing ammeter, eliminating a few wire nuts I found from the previous owner, etc..

Replaced the fusible link with an in line 30A blade fuse, but after researching this evening apparently that is not the way to go. It popped sometime during our first drive, and the car was dead at the gas station again after getting there. We just put in a new fuse and continued on driving. Once it cooled down I pull the fuse on one of the Spal rad fans to lower the load in the system, and it seemed to help (fuse is okay).

Now I'm troubleshooting a light wiring issue. The dimmer switch is disconnected (has been since the PO) and two of the pins on the connector were jumpered so that the dash lights work. At one point today, the parking lights flickered on and off by themselves with the switch in the off position. We just turned on the lights to stop the flickering. We pulled the jumper to see if that would change things, and it just killed the dash lights. I can wiggle the ignition switch harness to aggravate the problem (and curiously get the dash lights to work without the jumper too). I'm now thinking per someone's either post (thanks!) that the blue w tracer IGN wire in the harness is shorted to the parking light wire somewhere in the harness (we repaired the visibly burnt sections, but obviously I can’t see inside the harness). This wire runs to the regulator, and could be causing some of the other charging problems.

The plan here is to do as suggested, and run another 12V wire (planning to repurpose the oil warning light feed wire that comes off the same ignition switch terminal as the burnt wire) to the regulator. Hopefully when I disconnect the current one it will fix the lights too.

Thank you guys for all of the suggestions and keep them coming. So weird, we drove this car on HRPT two years ago in the exact same configuration (only difference is water pump speed to get better cooling at low RPM) with the electric fuel pump and dual fans, with ZERO electrical problems.

I'll post up tomorrow with the results of the day.

-Dave

If it was my car I would relay feed those fans and fuel pump so as not to draw on that old stock wiring, I would also run a #6 wire wire from the alternator output stud to the battery with a 50-60 amp fuse to take the load off those old connections, strap the ammeter and run a voltmeter.

Great suggestions 4406bbl.

Sheldon

Don't run a blade fuse (30A isn't enough anyway), run a maxi-fuse in place of the link. There's a conversion on-line somewhere for the links if you can't find the spec of the original link.

Those fans draw alot of current, >50 Amps...
Far more than the entire Mopar OE electrical system...
If you still are going to run them, you should use relays directly wired to the battery for switching..

Just my $0.02...

Fans and fuel pump are relayed already. Sorry, I guess I should've noted that earlier. Fuse hasn't popped, and we are pressing on with no additional changes yet. Replacing the blue wire tonight I think. Thanks again guys.
-Dave

Hey Dave, Rich here. good to hear you got it fixed and are underway. Take care buddy.

Even though the fans and fuel pump are relayed the charging current still has to go through 2 bulkhead connectors and the ammeter, the bulkheads will not take this abuse long term. The easy solution is to run at least a 10 gauge wire and 30 amp fuse from the alternator post to the battery, 6ga and a 60 amp would be better. It would be wise to add another ground from the battery to the alternator or block as well. This takes the heavy charge current off of the old wires and bulkhead connectors. You are having problems with the fuse link and blue wire because they are overloaded, a jumper will solve this. The stock circuit runs a black wire from the alternator to a bulkhead,then to the ammeter, then turns red and tees for the headlights, then red to another bulkhead, then turns blue and end in a fuse link at the starter relay. A simple 10ga wire and 30 amp fuse eliminates the heavy load on all those connections, try it , I have been doing it for 30 years now, might save you a fire.

May be too late, but If you have any loose ends to wrap up on your way to Arlington, you might be coming very close to me on your way through. LMK if you need anything before you disembark. goodysgotacuda@yahoo.com

Guys, thanks a bunch again for all of the help. As everyone said the 30A fuse wasn't enough, and we talked to the guys from Painless and they hooked us up with a maxi fuse holder to replace it with. The hotel we were at in Arlington was great, because there were two entrances with covered driveways and one was under construction. We were able to just use that one as our own personal garage to check everything over. Got the fuse holder changed, and are running a 40A successfully all day today on the ride to Texarkana (what a crappy venue they picked, a dirt field? seriously?). They were saying to start at a 70A, but we figured we can creep up on it if we have issues.

So far so good! Hope to be done doing wiring work for this trip, but somehow I doubt it. I do like the idea of running direct from alternator to the battery. I'm hoping to make this trip home and we'll look at doing that when we get home...

Rich! What's up man!?

Thank you all again,

-Dave