Electrical

Asked by Jun 15, 2016 at 02:03 PM about the 1975 Chevrolet El Camino

Question type: Maintenance & Repair

My 1975 El Camino has a problem. The generator
light will not go off. The alteranator tests good, the
gages fuse is good,  it shows 12.6 vdc at idle but if
you rev it up, it shows and maintains 14.6 vdc at
the battery while running (until you shut it off and
re-start), however, the generator light will not go
off. The new engine was installed at a professional
shop, the new tranny was installed by a similar
shop, the electrical and tuning wrre both done at
professional shops as well. Someone missed
something but nobody has a clue. Help!

6 Answers

100,565

Sounds like the internal voltage regulator has a problem, it should have a low output of 13.8 volts and a high of 14.2, your high voltage is not that far out of specs but the low is too low.

Is it possible tbat voltage is feeding back from the alternator causing the gen light to come on? Charging is not the problem. I tested it a rebuild shop I used to work at. The "A" circuit light is on at rest, the regulator turns on at approx. 600 rpm, charges at around 14.5 no load and around 14.0 with a 75 amp load. On the car, the light should go out when tha alternator is charging. The system shows that it is charging

100,565

I know it is charging that is evident from your high voltage reading, it's the low voltage that is off and the fact that it is not turning off the light and the regulator is suppose to do so if it is operating properly. see pic.

Gotcha! Thanks for your parience with me! So, I'm thinking faulty regulator. ......and/or, is it possible for the brown wire to the alternator light to be grounding somewhere, turning on the light, or would that blow the gage fuse?

100,565

It would blow and then you would not be able to shut the engine off due to the feedback from the alternator as that lamp is part of the exciter circuit for the alternator.

That makes sense. Thank you. I will replace the regulator. It's the only thing that makes sense.

Your Answer

El Camino

Looking for a Used El Camino in your area?

CarGurus has 199 nationwide El Camino listings and the tools to find you a great deal.

ZIP:

Chevrolet El Camino Experts

  • #1
    John Brensinger
    Reputation
    360
  • #2
    Js08016
    Reputation
    320
  • #3
    F_O_R
    Reputation
    220
View All

Related Models For Sale

Used Chevrolet Camaro
401 Great Deals out of 30,669 listings starting at $3,550
Used Chevrolet Corvette
286 Great Deals out of 20,556 listings starting at $2,990
Used Chevrolet Impala
511 Great Deals out of 34,059 listings starting at $950
Used Chevrolet Monte Carlo
12 Great Deals out of 1,304 listings starting at $2,500
Used Ford Mustang
674 Great Deals out of 37,812 listings starting at $895
Used Dodge Challenger
274 Great Deals out of 22,223 listings starting at $6,999
Used Dodge Charger
396 Great Deals out of 27,754 listings starting at $1,979
Used Ford Ranchero
52 listings
Used Chevrolet Nova
154 listings
Used Chevrolet Caprice
187 listings starting at $10,595

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.