sportfury

I have a '66 sport Fury with 440 Super Comando that I purchased recently.

Runs great, but then battery was dead after a few days.

Checked the voltage at the battety with engine running: 12V.

Checked the alternator and noticed only the Bat terminal was connected, also the cover on the voltage regulator was missing.

I replace the regulator and hooked up the alt field terminal to the voltage regulator field terminal.

I downloaded a wiring schematic and connected the dark blue wire (ign) to the IGN on the voltage regualtor.

Started the engine and the voltage was 14.5 the idle increased and the voltage went to 17+ and the battery started to boil.

I turned on the IGN and measured the voltage at the votagel reg IGN terminal: 10V and the BAT on the alternator: 12V.

I diconnect the field terminal on the voltage regulator, start the engine and voltage at the battery is 12V.

There is a warning lable on the voltage regulator "do not let termails short to ground).

I did a continuity check from the terminals to ground (VR case) and found the terminals do short to ground. Then I disconected the Field wire at the voltage regulator and found the short went away.

I checked continuity of the filed terminal to ground and it was shorted.

I would really appreciate any help to resolve this ASAP.

Thanks!

440roadrunner

You have already FOUND the area of the problem, which is getting to be the pain of many Mopar owners, I.E. "voltage drop" in the ignition circuit

Read this excellent article, which, even if you do NOT perform the bypass operation, points up some of the problems with these cars, namely, bad connections, damage to the bulkhead connector

http://www.madelectrical.com/electri...p-gauges.shtml

Notice in the article that there is a simplified diagram

The voltage drop you suffer is in the path in the diagram:

IGNITION power comes from battery -- fuse link -- bulkhead connector (red) -- ammeter circuit -- WELDED SPLICE -- to ignition switch CONNECTOR -- (the following is not shown on the simplified MAD diagram) -- through the SWITCH -- back out the ignition switch CONNECTOR (on the dark blue "IGN1" or "ignition run" wire -- back out the bulkhead on the dark blue -- to the ignition and regulator

Your top suspects are failures and bad connections in the bulkhead connector

bad connections in the ignition switch connector

bad ignition switch

poor connections at ammeter

failure of the welded "in harness" splice YES it does happen!!

The REASON that you are measuring 12V with the regulator disconnected is that you have removed the LOAD at the end of the circuit path.

Let's say you have an extension cord which is WAY too long and WAY too small, you've run a cheap extension cord 400 feet!!! from your house down to your boat dock. You can't get the air compressor to run!!!. So you unplug the compressor, and guess what!!! You measure 120V!!! WHY??? Because at the end of that long run of cheap cord, the only LOAD is your meter, which draws almost nothing.


SO to measure this IGN harness drop, you must have the

1 regulator/ alternator all hooked up and in working condition, so that the field draws current (2--3A)

2 The IGNITION must be drawing current, and that means that if you have POINTS they must be CLOSED


Pull the bulkhead connector apart and inspect it, repair as necessary, The MAD article posted should give you some good insight into how this happens

Inspect the ammeter terminals for tightness, and if you have the factory rubber molded terminals, once you get the car running and charging, "feel" them for heat, which would indicate problems

If your meter cannot seem to chase down the drop, suspect the in-harness WELDED SPLICE. These have failed. First one I found was a LONG time ago, about 1970 or 71 in a friend's 68 RR

Unhook the battery, remove the cluster, and untape the harness from the BLACK ammeter wire down into the harness. The splice is a few inches down in the harness from the ammeter black ring terminal, and has several branches
It feeds

the fuse panel "hot" buss

the headlight switch "headlight" power

I believe the wiper switch

the ignition switch

IF you cannot run this down, one workaround might be to run the "ignition run" loads off a relay. Be careful though, because BEFORE the blue "IGN1" goes through to the engine bay, it also branches off and feed power to the cluster warning light(s) and the gauges as well as ignition.

sportfury

Thanks for the excellent response.

I will get working on this and post the results!