Stumped! HELP!! - Resolved

[seabeelt]

Ok folks a couple of issues - may or may not be related

First - alternator light.

Initial conditions - new battery, new 95 amp alt From Allison's

Symptoms - car off, key in run position, alt light ON - normal
Start car, alt light initially off but grows gradually brighter after a couple of minutes of run time
Voltages - car off battery reads 12.3 v, car running battery reads 15.2 volt ( load or no load ( lights on, heater fan on, heated seats on... As much load as I can muster still 15.2 v))

On a lark, I stopped by autozone and had them come out to the car an test the battery,and alt with their portable tester. All tests came back good. Alt charging, battery fully charged. Hmmmmmmmmm. Not that I put 100% faith in their tests and equipment, but may be Ok??????

I think the service manual says 14.8 max, but I'm thinking old style alternators and perhaps some small meter error soooo 15.2 is not too much???????????

And why would that darned light be on????????


Second issue. - it followed the first one by a couple of days - gauges do not work except clock and speedo which is mechanically driven - no tail/stop lights no temp, no oil, no tach, no fuel. - gauge lights all work (headlight, hi/low, directional signal and instrument night lights), just no gauge readings.

Checked thus far- ignition switch - both sides work, no loose wires, no burnt connections ( it's a 71 with spade connectors)
Trace wiring to fuse box, key off, all dead except number 1 - normal, key on, power to rest of fuse box - normal
Check all fuses, clean contacts - no change in gauge operation, all spade connectors good to fuse box, no un connected wires

Pulled the dash panel all gauge connectors in good order, Checking grounds for that circuit ( white wire black stripe). Cannot find any loose grounds in the circuit of that wire ( side note, clock and ebrake light use the same ground and both still work

So,folks for the first time the wiring in this car has me stumped, I mean really stumped.

I'll go back to square one and start tracing individual circuits for each gauge, but any insight would be most helpful

Thanks in advance

[azruss]

I assume the new alternator has its own built in regulator. Is the OEM reg on the DS inner fender still in the circuit. My 70 with a stock alt would charge that high and it will eat your battery. That's the only thing i can think of that might make the alt light go bonkers.

[seabeelt]

Yes internal regulator on the new alt. old regulator no longer in the car.

For the gauges, tested the black and white wire to ground (it is the ground wire, or at least appears so on the diagram) it tested good at each gauge plug. This would seem to indicate that it's not a ground problem

Started testing the black and yellow wire back to the fuse box as it looks like this is the power wire. Was getting about 38 ohms coming from the fuse terminal for fuse 7. This would appear to be too high, but I haven't eliminated everything from that wire yet that might cause it to loop back. Argggggg......

[marinewithafiat]

Hey,

I'm having the exact same issue. No stop lights, backups, gas gauge, oil gauge, etc. My turn signals dont work either. Instrument panel lights are good. clock, and speedo good. Checked the fuse box and plan to change all fuses. With 12 slots in the fuse box, are all of them supposed to have a fuse? Ive only got 11 starting with the second from left and full to the last on the right. Perhaps that's why im missing lights.

If I figure it out soon, ill let you know what worked.

[So Cal Mark]

did you bypass the charge light relay? If you look at the wiring diagram for the charge light, with the key on/engine off, power goes through the charge light and grounds through the green/red wire at the alternator. Once the alternator is charging, the ground through the alternator goes away as the alternator puts power back to the green/red wire. Without a ground the light goes out. Without power to the other gauges, you're probably getting power the opposite way; from the alternator back through the charge light

[marinewithafiat]

You know, this may explain something that happened yesterday. Before yesterday I had no headlights or running lights. Front left side and front right parking lamps were good but those were the only lights I had. Then I pulled the radiator and yanked some old relay switch I think from the radiator fan that was spliced in some weird way with one wire connected back to itself and zip tied to the top of the rad. Then I started pulling the alternator. disconnected it, got the top bolt off. after a full day still tryign to get the bottom bolt out. I decided to take a break and figure out some electrical if I could. connected the battery and turned on the lights and voila! I got low and high beam headlights, all parking lamps, except the right one (bad bulb perhaps) and all running lights. But now the flashers don't work, still no turn signals, no gauges, stop lights, backup lights.

I don't know if it was disconnecting the relay that did it (doubtful since it was only connected to the fan and thermo switch, or it was due to the alternator being disconnected. If the alternator wasn't working at all and I disconnected it, could that have opened a circuit that was previously closed? I've got an electronics background but haven't done this stuff in a long time and certainly not with cars.

[marinewithafiat]

A lot of this could also just be a bad fuse, which I'm replacing soon when I get my fuses and other stuff from csaba.

If csaba ever has an IPO on the stock market, I'm buying a ton of shares!

[So Cal Mark]

part of the fuse box gets power directly from a wire that connects to the battery post on the alternator. If you have that disconnected those circuits won't be powered

[seabeelt]

Mark, the green/red wire from the alternator is connected to the warning light wire ( yellow wire for the 71). Battery charge Relay was removed and a jumper installed between pin 85 and 30/51 wires It has worked fine up until now.

Alt output post to battery / fuse box connection is good. Power is present at fuses 1 and 2 with the key off. With key on, there is power to fuse 9 ( pink wire), key in ignition light comes on when key is inserted( not that this matters with current issues) so that circuit works.
R/

[seabeelt]

Pouring over Brads diagram last night, it looks like fuse 9 ( pink wire from ignition switch to fuse box) powers the gauges and the stop light switch. Thing is that with the key on, there is power to the fuse, fuse reads good as well. I may swap it out just to make sure, but this is what has me stumped. White wire from fuse 9 feeds the stop light switch and the gauges. A broken connection at the spade connector??????? Hmmmmmmmmm.

More to follow

Had a chance to Poke around some more last night and Well all I can say is that "someone" has a big foot, Found a broken splice in the white wire that feeds power to the brake light switch and gauges. I will repair that this weekend and put the dash back together ( love those 4 screws that hold the gauge panel on ..... Not). That still leaves the alternator light issue to solve........

[seabeelt]

Ok, the dash is fixed, now for the alternator light.

Light is on " bright " with car off and key in the run position. - check
Light is on slightly less bright with the car running.......

Voltages and tests
Battery car off 12.6 v - static charge removed
Battery car running @ idle 15.1 v - no loads except for car running all accessories and lights off
Battery car running @ 1500-2000 rpm 15.1 v - no loads except for car running, all accessories and lights off.

Negative voltage loss test - alt casing to battery ground. .01v
Positive voltage loss test. - alt output stud to battery + - no loss reading., 0.00

Voltage load test - car @ 1500-2000 rpm , all accessories on (heater fan, radio, wipers, heated seats, lights, fog lights) 13.2 v at battery. ( and you can hear the motor take up the load as it requires a bit more umps to spin the alt)

Belt is good, no slipping

Continuity test. Output stud to battery - 0 ohms
Single white wire to 3 pin plug on alt - 0 ohms
Green wire from 3 pin alt plug to " yellow wire" to black wire ( old alt external relay connections pin 30/51 to pin 85 per install instructions) - 0.02 ohms. Black wire goes to alt light on dash, through bulb and to blue/black wire to fuse 10 for power.
( circuit works because light is on and alt off) ground is through alt.

It would seem that the alt is not removing the ground when running thereby not turning off the light.

Thoughts everyone....... Part of the solid state voltage regulator pack on the back of the alt?

[seabeelt]

Bump' Brad, Mark, anyone.....

[lanciahf]

Mike I did the same thing you did, converting the old external regulator alternator to the new style, internal regulator. In my case I used a 65 amp alternator from a later spider, I followed the directions on IAP's website and everything worked as it should.

If you disconnect the alternator warning light from the alternator does the dash light go out?

[seabeelt]

Yes, it then becomes the open circuit. Mark sent directions with the alternator. It has worked fine for the last two seasons. Just now having a problem. I ordered a voltage regulator for it ( it's basically a ford G3 alternator) off the web. Should be here later today. We will see if that makes any difference.

[seabeelt]

Update..... Spent 10 bucks on a replacement voltage regulator. no dice. So replaced the alternator. All is well. It's just one of those things I guess, try as you might your brain does not want to accept the inevitable. At least I eliminated ALL other possibilities first. There must me another electronic component inside that needs to be replaced, one that isn't over the counter available. I'll tackle that another time. For now back on the road