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Quote:
Originally Posted by timmy2 View Post
From the first picture it looks like an internal VR as no Black DF wire is visible.
(Normal for a 1982)
Find the blue wire at the back of the gauge and check it for continuity to the blue wire at the alternator (use a long jumper wire).
The 14 pin connector at the rear fuse panel is the only designed break in the circuit. You should probably check the connection there as well.
Check the bulb in the alt lamp as well.
Yes, focus on the blue wire from the alt light to alt by removing the alt and making sure
only the alt is connected to the alt light. Once the blue wire is disconnected at the alt,
the light should be off with the key 'on'. Next, you can check the light's current output
using an amp-meter. The bulb should provide a minimum of 50 milli-amps to start
the alt.

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Old 06-29-2014, 06:57 AM
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MJP MJP is offline
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Any updates on this one? I'm chasing the same problem. No charge from my Marchal at low rpm, solid 14+ volts with 3k rpm. I swapped in my spare Bosch and all's well. I had the Marchal checked and replaced it, still no charge between 1k and 2.5k rpm. I swapped voltage regs too, didn't make a difference.
Old 07-03-2014, 09:05 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #42 (permalink)
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MJP,
Could be dirty commutator, worn brushes failing diodes or a poor electrical connection.
Did you use a new Electronic VR? (Assuming remote VR)

Is the Bosch internal or external VR?
Old 07-03-2014, 09:39 AM
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Quote:
Originally Posted by MJP View Post
Any updates on this one? I'm chasing the same problem. No charge from my Marchal at low rpm, solid 14+ volts with 3k rpm. I swapped in my spare Bosch and all's well. I had the Marchal checked and replaced it, still no charge between 1k and 2.5k rpm. I swapped voltage regs too, didn't make a difference.
I think you can install a resistor across the alternator light.

I found this with a search:

Paul,

With the original voltage regulator, the resistor is not required.

It appears more current is required to gain excitation with the internal regulator. Later cars took care of this with a 4W alternator light bulb. On earlier cars, installing the larger bulb is not possible. The fix is to install a resistor in parallel accross the 2W bulb (91 ohms).

The fix on your car is to ensure voltage at the bulb, and that the bulb is working.

Sorry for the multiple posts.

Marlin
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Old 07-04-2014, 05:43 AM
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Quote:
Originally Posted by kodioneill View Post
I think you can install a resistor across the alternator light.

I found this with a search:

Paul,

With the original voltage regulator, the resistor is not required.

It appears more current is required to gain excitation with the internal regulator. Later cars took care of this with a 4W alternator light bulb. On earlier cars, installing the larger bulb is not possible. The fix is to install a resistor in parallel accross the 2W bulb (91 ohms).

The fix on your car is to ensure voltage at the bulb, and that the bulb is working.

Sorry for the multiple posts.

Marlin
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"..It appears more current is required.."

I suspect not, more likely the resistor is there as a failsafe since incandescent bulbs are prone to failure.
Old 07-04-2014, 06:41 AM
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Guys, MJP said all is well with the Bosch, it is his Marchal he cannot get to charge below certain RPM's .
Old 07-04-2014, 08:58 AM
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The Bosch alternator's back in my car, all's well. The Marchal is on the shelf. I found an interesting troubleshooting table in Up-Fixin (Vol III, page 103) . The dash light is more than an "idiot light". "The indicator light is a control resistor for the alternator field and can also be used to troubleshoot..." Per the table, "medium glow" at low rpm and "not lit" at high rpm means "open alternator phase winding or shorted two phases". I have to take it back to the shop and find out if they can figure out what to do next. I'll post the results.
Old 07-06-2014, 05:16 PM
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Sorry guys, broke my boat so I had to take a few weeks (ok months) and fix that one 1st. For you boat folks I separated the cap from the hull... lot of glass work, but if she breaks again it wont be where I fixed her!

So I tested the blue wire and it was good. Rechecked all the grounds and power connections. No joy!

I then drove over to WallyWorld and bought a cheap 700CCA battery that I judged would fit in the space. I just laid it in there and connected stuff. Zazam we had a working charging system! All I can figure is that something in the light weight AGM battery blew when it got disconnected. While it would run the car and re-charge there was something wrong.

There is one issue... Now I still am not getting 14+v, but when I ran it I started at 12.3 and after 10 minutes idle I was at 13.8. This is measured across the battery terminals. I don't know. I'll drive it for some time adn see how it is fairing. The alternator light is off now, though! so I think I am making positive progress!

Best regards,

Michael

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Old 09-21-2014, 07:38 PM
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