Masters degree credit available for alternator charging question

[Pete Masterson]

It may simply reflect the engine alternator not able to put out significant amps at low idle speed -- or the voltage regulator is failing to 'kick in' until revs are up a bit. The controlling device is the voltage regulator associated with the alternator.

Some alternators have internal voltage regulators and others have external regulators. I'll leave it to someone with a model more contemporary to yours to comment on what's likely on your FC. Keep in mind, a previous owner may have replaced the alternator (and voltage regulator) at some point, making yours no longer match the OEM arrangement.

It is unlikely, but if you have a sophisticated inverter/charger control module (such as the Heart Link 2000 R as installed (after market) in my coach) the charging from the alternator would be controlled by that device instead of the normal regulator.

Pete Masterson

'95 Blue Bird Wanderlodge WBDA 42

"aeonix1@mac.com"

On the road at Lockhart, TX.

On Nov 14, 2008, at 1:56 PM, hippieforever3 wrote:

I'm posting this here rather than the FC forum bcause it may be a 

generic issue across models.

I've looked a few diffent versions of the charging / starting 

schematics and can't find anything that explains what I'm seeing.

Consider this sequence;

1. Turn on master power switch in the battery compartment

2. Observation - dash voltage is showing 12+ to 13V, no current

3. Turn ignition key

4. Observation - dash voltage momentarily drops to 10.5V

5. Engine starts

6. Observation - Dash voltage rebounds to approx. 11.5V, no current

7. Momentary tap on the throttle, approx. 1500rpm or more

8. Observation - Dash current now showing +50a to 100a, voltage starts 

to climb toward 13-14 volts

It's steps 6 - 8 that mystify me. I can understand the voltage 

rebounding after the starter surge but why no current before revving 

the engine?

This implies a relay somewhere that only kickes in after a little rpm 

rev. I don't see it on any of the various BB schematics I've got. Is 

there an internal relay in the alternator?

Has anyone else seen this or do I have some "custom" configuration?

Movin on,

GPSGary

1984FC35

------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:

    http://groups.yahoo.com/group/WanderlodgeForum/

<*> Your email settings:

    Individual Email | Traditional

<*> To change settings online go to:

    http://groups.yahoo.com/group/WanderlodgeForum/join

    (Yahoo! ID required)

<*> To change settings via email:

    "WanderlodgeForum-digest@yahoogroups.com" 

    "WanderlodgeForum-fullfeatured@yahoogroups.com"

<*> To unsubscribe from this group, send an email to:

    "WanderlodgeForum-unsubscribe@yahoogroups.com"

<*> Your use of Yahoo! Groups is subject to:

    http://docs.yahoo.com/info/terms/