alternator not charging- SOLVED

[gr79]

Alternator checked good the other day at AZ. !G large case side terminal.
Wire harness alt to regulator checked good with DVTM, ohms and volts.

Disconnected battery.
Pulled regulator and unplugged connector.
Corroded radio condenser wire broke off the condenser. Time for a new one.
Cleaned connector and regulator.
Brushed off 20 years of road 'fuzz', cleaned metal contacts, sprayed with CRC QD Electronic Cleaner.
Cleaned screws and mount area of rust to shiny metal.

Tested regulator connector F, A, then S per manuals. F ok, A ok. No power at S.
Ignored that for now but that was the big clue to check out why later.
Assumed Motorcraft regulator was ok (and is).
Reinstalled regulator. Freshened up ele tape and harness loom where needed.
Started engine. Same deal. No charging.

Later came.
Studied EVTM and shop manual for clues where to check S wiring, regulator back.
Noticed S wire routes thru harness to gauge cluster connector for power.

Ever since the cluster was pulled to install two new bulbs, the charging problem started.
Left multiwire connector was seated in cluster pcb pocket.
On a hunch, decided to check the multiwire connector by the speedo.
Pushed on it and it snapped down into its pocket. Somehow it became unseated or has been.

Reconnected batter and restarted engine.
BINGO. Everything is back on line 100%. VDO volt gauge read normal 14v for charging.
Did not know that a cluster connector could cause such a thing.

Total time about 4 hours split between two days.
Saved at least 100.00 in parts. Total cost for repair is zero.
Big bonus was finding the loose ps to block bolts doing a bracket check.

[83GTTops]

Wow, good find. Funny how the VDO Gauge can cause that much havoc

[massacre]

Glad you got it figured out!

[85GTGuy]

Funny how the VDO Gauge can cause that much havoc

The way I'm reading his post, it wasn't the VDO gauge that was the issue.... it was a "multiwire connector by the speedo" that was not fully seated.

@gr79 - Glad you got the problem solved... good troubleshooting there!

[gr79]

Thanks for the complements.
Yes it was the main connector by the speedo.
The VDO gauge clearly indicated no charging. A real time diagnostic tool.
Is wired to dash electrical at sort of the end of the line to monitor that critical wiring circuit.
Hmm,,,prob could wire another gauge all the way back at the taillights or else ware like ignition?

The 5 new non-led 5w wedgee bulbs are working out great. Main gauges are clear and bright again.
Somehow the turn signal indicator lamps are working correctly too. They were operating reversed..
I think the bezel was out of position or something. They started working ok after it was reinstalled.
Bright lights indicator inop no big deal. Bulb is fine. Sometimes they correct themselves.

[fgross2006]

The way I'm reading his post, it wasn't the VDO gauge that was the issue.... it was a "multiwire connector by the speedo" that was not fully seated.

@gr79 - Glad you got the problem solved... good troubleshooting there!

Ive had my cluster off a few times this summer for various things and I noticed that my connector by the speedo has a broken clip on one side so I have to place my hand behind it and make sure it stays in place until I seat the cluster.

I had to replace my IVR because it stopped working from messing with the cluster so many times. My fuel temp and oil pressure gauges all maxed out. I replaced the printed cluster circuit board from NPD together with the IVR. My gauges went back to normal, BUT, yesterday after moving my car to enable my neighbor to have a new fence installed, I went to move my LX back to the end of the driveway and could not get it started. It started at first, was letting it fast idle waiting for the kick down then it cut out.

Tested the coil and coil connection to distributor for spark and it has spark. I was able to get it to turn over with starting fluid but it cuts right out. Checked for fuel pump relay and its audibly energizing. I assumed my Walbro went bad, ordered a new one that arrived today. But then I got to thinking, my low fuel light has been on the past few days while the gas gauge shows half a tank. I tried swapping the low fuel switch in the glove box but both switch's produced the low fuel light. i assumed the wiring or the switches were bad, but now I'm wondering if my fuel gauge sender is bad. I replaced that with one I got from LMR back around 2015ish.

Tomorrow I'm gonna fill a gas can and add 5 gallons to the car. If it starts then I'm a doofis and I need a new fuel level sending unit. Thing is, either way, the tank has to be dropped. So if its the fuel level sending unit, I may as well swap the fuel pump anyway with the new Walbro and keep the used one as a spare if it is functioning.

Just wanted to get feed back on this one.