Ammeter readings question....

[ramairthree]

I am currently sorting out my wiring on my 74 RR.

I have no lights working on the rear, but am still just sorting out the dash board forward.
Some complications are no wiper motor, no washer resevoir or pump, shaved side marker lights front and back,
and other issues like a removed and shaved antenna, etc.

The front turn signals work, as do the dash indicators.
My outer headlights come on, but no inner bulbs in, and no power according to test  light from the inner sockets.  Although the dimmer does switch off the outer head lights.

Power to my dome light and the gauge lights also work.  Fully adjusted to high by the head light switch rheostat the gauge lights are of course not bright by modern standards.

speedometer/odometer is working, temp guage also, and ammeter.  fuel guage and oil pressue do not appear to be working, but I have not actually gotten started looking to see if the sending units are there, the fuel sender ground, etc.  Other than a 3 mile drive at 30 - 40 mph, it has only had yard driving.  I got it in the fall, but it has been sitting at a friends and I have not done more than some cosmetics, oil change, etc.  Now at my house again I can get at it an hour here and there.
Let's just say after a burst of some interior work, I have barely gotten started on it.  (very limited time, and was getting a javelin road worthy)
With no lights on, the ammeter works and reads as it should.

But with the lights on, every few seconds the needle dips almost all the way to the left, then back to normal reading.  The lights do not dim when it does this.  Tomorrow i will dig out the voltmeter.  If the alternator is giving a steady chage, am I looking at a voltage regualtor issue, a gauge issue, or a wiring issue?  Maybe I am being thrown off by the lights not dimming when it does this.

Thank you for any information.

[Nacho-RT74]

I think the first stepo is to know HOW TO READ an ammeter ( not everybody knows to read it )

and IMHO, its a missconception coming from factory when they began to acll it an ALTERNATOR gauge where really is a BATT gauge. Why ? you'll never get a DISCHARGER from an alt, but from BATT.

some interesting reading about that here:

http://www.dodgecharger.com/forum/index.php/topic,33574.0.html

CHECK for tightness and cleanest of terminals on back of ammeter and bulkhead, specially on this case at bulkhead. The lights consumption its between bulkhead and ammeter on alt side, SO a loosing conection on bulkhead will make the ammeter read the discharge going to anywhere around and alternator not feeding that

[ramairthree]

thanks for the link nacho.

some more hints-
with the low beams on, both sides work, ammeter normal.

hit the dimmer switch, no high beam indicator comes on, no power to high beam sockets, low beams turn off,
and the ammeter does the negative diving dance and bounce...
and, in the right light conditions with dome light on,
I DO get dimming when the meter goes neg.

front turn signals work, but not hazzards.

seat belt warnings not hooked up.

where between dimmer switch and high beam sockets would be high yield to find my drain?

Thank you again.

[Nacho-RT74]

the source to highs and lows is the same from headlight switch, since the floor switch is simplty a selector, not really an ON/OFF switch. The only wire you can check is the high beams wire ( red ) running from floor dimmer switch up to bulkhead, then straight up to sockets. It could be a damaged floor switch, shorting somehow.

The high beams indicator on cluster is an splice from the red wire from high beams line inside the cab, so if cluster bulb is fine, then I think we are getting closer to the problem, a damaged floor switch

hazzards, check the flasher first. Do you have turning ?

dimming and ammeter going discharge are in direct proportion, Normal reading under that condition

[ramairthree]

thanks, I will start from the dimmer switch.  all other guage lights including parking brake indicator seem to be working though.

as for the hazzards,
I do have working left and right front turn signals.  Although unpredictably on few occasions the passgener  side turn signal does not come on.

When I turn on the hazzards, I either get no flashing,
or flashing on just the driver's side and none on the passenger side.  No rhyme or reason to the randomness.

The two side marker light sockets appear intact, and just hanging, as the marker lights were shaved by the previous owner.  I need to pick up some 168 bulbs just to see if they are working.

Again, the rear maker lights are also shaved, and those harnesses look cut with no socket.  I am adapting to not being able to get to my rear light sockets from the trunk, and have not gotten into the rear lighting yet, although for now I can assuredly say there are no lighting when headlights on, in reverse, or when hit brake.

[ramairthree]

well, since I did not have a new dimmer switch handy,
with some bright daylight I followed from the sockets back.

At some point, the  harness must have been misrouted and touching something very hot.  Probably the exhaust manifold as that is the hottest thing I can think it would have reached.

In a small part of the harness, it had melted through and melted off some of the red wire insulation in the harness.
This was now touching metal.

I pulled the harness wrap a handwidth arround it, and also some insulation melting but no wire exposed through the green striped.

Some electrical tape for each wire individually, then some new wrap for the harness,
and I now have high beams, plus the dash indicator with normal ammenter readings.

For once I got lucky, and started on the easiest end!

The side marker sockets are not working up front, I did test with bulbs.  But they are just hanging sockets I was testing due to the marker light shaving the previous owner did.  Soon I will be able to get on to the horrendous mess that has been made of the tail light harness.

Thank you again.