66 valiant wiring help

[VDART]

Just acquired a 66v100 2 door post.
pulled apart the connections at the firewall-- cleaned up with sandpaper/contact cleaner (noticed some melted plastic)
(downloaded wiring diagram)
Found on the engine side the dk blue wire(connection "Q") has been hot & melted the casing, I cut the harness apart & replaced this wire.
dropped dash gauges-- same dk blue wire melted-- going to splice in replacement tomorrow.(right behind ignition switch melting starts)
What is next step--
temp gauge moves slightly right at 1st start then returns
fuel gauge no movement(ground strap intact at tank)
ammeter moves but registers slight discharge.
so far that is the only melted wire, I'm cleaning up old splices & nicks as I find them.
The back of the gauges looks ok, I'm going to remove & scuff the nuts on the back. thanks Lawrence

 

[pettybludart]

First things I did on my 66 Dart,was bypass the amp meter then drilled throught the block at firewall and ran a thicker guage power wire.These are the weak links in the Early-A harness wiring.Good luck with your new ride.

 

[67Dart273]

hope the PM helped, Vdart, post back here when you get into it further

 

[RedFish]

The dark blue from ignition switch feeds the mechanical voltage limiter on the instrument panel.
That limiter may be a plug in unit on the back of the panel or built inside the fuel gauge.
In either case it can be the source of the original problem.

 

[BillGrissom]

Your melted firewall connector is a common problem in 66+ A bodies, and continual warnings to fix that on FABO.

I replaced the "in fuel gage" dash regulator with an electronic one. Search "voltage limiter" and "Plymouth" on ebay, or the link RedFish gives.

If you feel really ambitious, look at my engine bay re-wiring, search "Modernized Engine Wiring" on FABO.

 

[VDART]

thanks for the tips-- right now I'm tracing the melted blue wire -- it also caused a copper break in the circuit board & I've started another thread on that.

My question -- how was this car able to start & run?
Lawrence

 

[BillGrissom]

thanks for the tips-- right now I'm tracing the melted blue wire -- it also caused a copper break in the circuit board & I've started another thread on that.

My question -- how was this car able to start & run?
Lawrence

My guess is the copper trace that melted was one running to the ammeter (far passenger's side of cluster). That acted as a fuse. The alternator could no longer charge the battery. The car could run fine off the battery. The prior owner was probably recharging the battery with an external charger (talk about "range anxiety"). Running the alternator with full-field and no outlet could have damaged it, but probably not.

Many posts on FABO about re-wiring to eliminate the ammeter and/or substitute a voltmeter. Do some reading.

 

[VDART]

I have been reading, read your article & that is not for me-- I might do the drill out of the 2 large leads through the firewall. Right now I'm just cleaning up things & getting a baseline before anything else.
I have a full 18 gallons of fuel to run out of the car-- might be a little road trip to the country today. Lawrence