Charging system

[daved]

Charging system light came on last week on my 1969 Fiat 124 Spider. So far I've verified that the charging system isn't working, checked all the connections, checked for voltage at the regulator & tried replacing it with a solid state regulator. Today I disconnected all the wires at the alternator & did a diode test which was good. Don't like the idea of removing the alternator & ordering a new one when there might be nothing wrong with it.

[baltobernie]

Does the red indicator light in the tach illuminate with the ignition On and the engine not running?

[daved]

Does the red indicator light in the tach illuminate with the ignition On and the engine not running?

Believe so, its certainly on when the engine is running. Have the battery out of the car now so its difficult to double check.

[daved]

Anyone?

[DieselSpider]

How did the alternator brushes look? If your getting voltage to the regulator and to the battery terminal then the brushes are the next thing to look at. They could be worn or simply just sticking in their holders.

[courtenay]

At the risk of asking the obvious, did you check, the voltage at the battery with the engine turning around 1500 - 2000 rpm? That should tell you whether your alternator is working.

[daved]

At the risk of asking the obvious, did you check, the voltage at the battery with the engine turning around 1500 - 2000 rpm? That should tell you whether your alternator is working.

Yes it was about 12 volt, thinking it should be 13-14 volt.

[daved]

How did the alternator brushes look? If your getting voltage to the regulator and to the battery terminal then the brushes are the next thing to look at. They could be worn or simply just sticking in their holders.

Haven't looked at the brushes yet, guess the next step is removing the alternator.

[courtenay]

How did the alternator brushes look? If your getting voltage to the regulator and to the battery terminal then the brushes are the next thing to look at. They could be worn or simply just sticking in their holders.

Haven't looked at the brushes yet, guess the next step is removing the alternator.

Yes, it should have been 13 - 14 volts. I'd suggest your alternator is pooched. You should be able to take it to a rebuilder or parts supplier and have it tested.

[daved]

Got the alternator out & took to both Advance & AutoZone. They both had an alternator tester & instructions showing them how to hook up my alternator to the tester, neither store had the connector that the instructions said was required.

[DieselSpider]

Got the alternator out & took to both Advance & AutoZone. They both had an alternator tester & instructions showing them how to hook up my alternator to the tester, neither store had the connector that the instructions said was required.

That is most likely due to stores dummying everything down so that they don't have to hire folks that know what their doing. A tech with a basic understanding of alternators would have had no trouble making the connections with the non-model specific harness with the plain clips.

Have the same problem where I work where everything is being distilled down to recipes so anybody with a basic understanding of English can monkey them and then they let the people who know how and why things are done go (Private Equity buzzword for this is had their "Positions Optimized") however when its Monkey See Monkey Do you end up with the situation where Monkey Don't Know and can't handle it.

You know what the regulator+, warning light and Bat+ connections are so with that info any tech who actually understood alternators and the tester should have been able to test it especially when working in a store that sells/stocks a wide variety of automotive electrical connectors and clips.

Feel your pain in getting something that should be so relatively simple done.

[daved]

How did the alternator brushes look? If your getting voltage to the regulator and to the battery terminal then the brushes are the next thing to look at. They could be worn or simply just sticking in their holders.

Did look at the brushes, not sticking & lots of material left

[DieselSpider]

How did the alternator brushes look? If your getting voltage to the regulator and to the battery terminal then the brushes are the next thing to look at. They could be worn or simply just sticking in their holders.

Did look at the brushes, not sticking & lots of material left

Then if you have power at the Bat+ and the Regulator Field Wire gets power with the Ignition on it should load up if the rectifier/regulator is good and the fields are not broken. The Diesel has a three wire regulator so it requires Bat+, Constant+ and Ignition on+ along with of course a good ground in order to field it and get it to load. The idiot light/tach wire is usually not required to field the alternator.

[daved]

Any other tests on the alternator I can do myself, Did test the diodes & found they are good. Haynes manual said I should have 4.5 ohms on the coil measured across "slip rings" By "slip rings" I assume that means at the brush contacts? Don't really know but 4.5 ohms seems low to me.

[spider2081]

I like to use local rebuild facilities. Have you checked online to see if you have an independent shop that specializes in alternator/starter repairs and rebuilding?? If so I would take it there. I am pretty sure they will know how to test the alternator and voltage regulator.