ALT gauge issues- clicks and pulses 69 DART. NEED HELP!!!

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DA69RT GT

DA69RT GT

South Florida Member
FABO Gold Member
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Location
North Palm Beach, FL
1969 Dart GT with 1976 360
Holley 670 Avenger
8mm Super stock wires
Champion RN12YC plugs
MSD Blaster 2 coil
Pertronics Ignitor/Electronic ignition
New battery, alternator and regulator (approx 3mo ago)

Noticed last week that it was sluggish in 1st gear... and backfired once thru carb. Thought it wasnt getting adequate gas (as you could goose the gas pedal to get it going) but definitely something wrong, but seemed to smooth out once you got going (and noted a broken plug wire).

So now the Alt needle/gauge clicks and pulses every 10 sec or so (see video). NOTE: Engine does NOT fluctuate as gauge pulses... maintains stable idle.

I just changed plugs, plug wires (one was broken at distrib) and distrib cap and had alternator tested (ok).

I know I will need a new harness and know the bulkhead connection is not in great shape... but hoping there is something else that may be culprit (could it be the gauge in the cluster?). I pulled cluster and did not see anything burned/fried.

Cant download videos? Heres a link with car off/key on: https://cvws.icloud-content.com/B/A...5D97&p=21&s=UrhXjVSW6dQ1Onk_f1dSlVvp7uI&teh=1

Any ideas? Thanks for any/all help.
 
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I didn't dl the videos. So what will pulse system voltage at few second intervals ? ... Mechanical voltage regulators. And the OEM system contains 2 of these. One for charging system and one for instrument voltage. There is a way to isolate and determine which is the culprit. Replacing both with modern solid state is typical.
( a vintage car clock pulses system voltage too but at closer to 3 minute intervals )
 
The IVR is just for the fuel, temp and gas gauge, the amp gauge is a stand alone. I would do the voltage regulator first. I would take the cover of the one in the car and see what it is doing.
 
halifaxhops said:
The IVR is just for the fuel, temp and gas gauge, the amp gauge is a stand alone. I would do the voltage regulator first. I would take the cover of the one in the car and see what it is doing.
Click to expand...
Correct but... the ALT' gauge is a very good indicator of whats going on throughout the system ( better than a volts gauge in this respect ). If it will twitch with turn signals it will twitch with inst' voltage regulator too. This condition has been seen and reported in other threads here. One very recently. What the fuel, temp, and oil where applicable, gauges are doing might be a clue also but recognizing a clue there isn't easy. Thermal gauges respond to voltage changes far too slow. Their being simple range indicators makes it difficult to tell they are reading consistently high or low.
Worst case scenario... the mechanical regulator contacts stick closed and fry a gauge or 3.
 
I totally agree, just trying to help out troubleshooting. Sounds to me like the VR is cycling. Just my thoughts.
 
I had a new Mopar p3690732 constant output regulator in the garage and installed it with same results. Car maintains great idle and sounds good- no change in engine idle as the ALT gauge clicks. But the volt meter does show inc voltage as it idles... jumping up and down.

Going to call Napa/Bennetts tomorrow and get another Regulator anyway-

I went around and cleaned/sanded all grounds I could find in engine area today. In doing so I noticed the thick red wire going into the bulkhead is not looking too healthy... could this be the issue? It does not seem to be very secure in the connection.
 
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Have a pic of the wire? Also while you are in there make sure the throttle cable is away from the bulkhead wires, don't ask why it was not pretty.
 
Threw a volt meter on battery and it jumped around quite a bit (13.75- 14.00) until she got warm- then sat at 12.85-12.90
and was 12.83-12.87 with a moderate idle. Did not see any big fluctuation (with alt gauge click/pulse) once it got warm.

Decided to pull the bulkhead apart and see what was going on there.
NOT GOOD... the bottom wire/second from left has the thick red 12v wire I was talking about.
Looks like there has been some previous issues and definitely going to have to tackle this. I would like to put a complete harness in it now but not in budget so I have a couple old wiring harnesses I may be able to salvage from. If anyone has any bulkhead connector plugs... I could use (3) of them. The ones on my car are cracked. I think the extra main bulkhead connector I have is in decent shape but need to check.

Anyway- I cleaned everything up the best I could using some sandpaper, electronic cleaner and dielectric grease and put back together. But plan on pulling everything apart hopefully in the next couple weeks and looking into the MAD bypass/volt gauge install.
Also picked up a new regulator and installed... still clicking. Starting to think its the ALT gauge itself.
1 DART bulkhead.jpg
 
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Ouch you have some work to do. I know wiring terminals, if you need help pm me.
 
Due to todays www, and madelectrical, and more, owners are instructed to drill through those terminal ports and shove a wire clear through. Before all that,
The auto service garage would put new terminals on the wires and relocate/secure them into previously unused ports.
In some cases there would be add on equipment, fog lamps, stereo, whatever, that drawed too much current through these terminals and the same failure could reoccur. In many cases their simple straight forward repair was good for another 25 years.
Low voltage can cause all sorts of strange issues in anything electrical. Did these weak connections cause the click/twitch in the ALT' gauge? Time will tell. Good luck with it.
 
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I found the correct wire terminals at my local NAPA store. They weren't tinned or otherwise different from OEM. Was about 4 years ago though. Good luck
 
RedFish said:
I found the correct wire terminals at my local NAPA store. They weren't tinned or otherwise different from OEM. Was about 4 years ago though. Good luck
Click to expand...
My napa is no so good I asked them to get me a fan belt by length and size they were lost. Sounds like you have a good one Redfish!
 
Hey Ray- that guy on Ebay doesnt have 10ga terminals...
and dont see any options-0 what do you suggest? Would 12-10ga work if I can find it or is there a strait 10ga...?
Thanks DC
 
10-12 should work fine, if you cant find them let me know how many I might have them.
 
I bought my packards local (2 minutes away)when I did some rewiring. Lemme know how many and size. I can pick some up and mail them to you if you like.
 
4spdragtop said:
I bought my packards local (2 minutes away)when I did some rewiring. Lemme know how many and size. I can pick some up and mail them to you if you like.
Click to expand...
Thanks so much... but I ordered a variety of gauges from an Ebay seller along with terminal release tool and crimper (thanks for the guidance/help Ray).
The only ones Im having trouble finding are the 10ga...
 
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