Alternator light

B

bill & joan satterfield

New member
Feb 6, 1999
135
0
0
Just in the last few days I have noticed that my alternator light is
glowing dimly. I havent driven it very far but it seems the light will
go out then maybe come on a bit later. I would presume alt. problems,
but my after market amp guage is still showing charge and working
normally. Am I about to have A failure or can I wait and see what
developes?
Bill 76 Edgemont
 
I had this problem when a Battery went bad. Got a new battery and no more
'GEN' light. Hope this helps..

>Just in the last few days I have noticed that my alternator light is
>glowing dimly. I havent driven it very far but it seems the light will
>go out then maybe come on a bit later. I would presume alt. problems,
>but my after market amp guage is still showing charge and working
>normally. Am I about to have A failure or can I wait and see what
>developes?
>Bill 76 Edgemont
>
 
Bill,

I know we've covered this before and I believe it's a bad instrument panel
ground. I believe it's also been covered in GMC Motorhome News, so if you
have those backissues, start digging. Again, since I'm on the road, I don't
have access to my library.

Patrick

> -----Original Message-----
> From: Bill & Joan Satterfield [mailto:bsnjs]
> Sent: Wednesday, April 28, 1999 11:14 AM
> To: 'gmcmotorhome'
> Cc: gmcmotorhome
> Subject: GMC: Alternator light
>
>
> Just in the last few days I have noticed that my alternator light is
> glowing dimly. I havent driven it very far but it seems the
> light will
> go out then maybe come on a bit later. I would presume alt. problems,
> but my after market amp guage is still showing charge and working
> normally. Am I about to have A failure or can I wait and see what
> developes?
> Bill 76 Edgemont
>
 
Sounds like your battery may be going south.
Dick 75 PB in Atlanta

>Just in the last few days I have noticed that my alternator light is
>glowing dimly. I havent driven it very far but it seems the light will
>go out then maybe come on a bit later. I would presume alt. problems,
>but my after market amp guage is still showing charge and working
>normally. Am I about to have A failure or can I wait and see what
>developes?
>Bill 76 Edgemont
>
 
Thanks to all. Will have batterys checked tho they are less than year old
Bill 76 Edgemont

> Sounds like your battery may be going south.
> Dick 75 PB in Atlanta
>

> >Just in the last few days I have noticed that my alternator light is
> >glowing dimly. I havent driven it very far but it seems the light will
> >go out then maybe come on a bit later. I would presume alt. problems,
> >but my after market amp guage is still showing charge and working
> >normally. Am I about to have A failure or can I wait and see what
> >developes?
> >Bill 76 Edgemont
> >
 
> Just in the last few days I have noticed that my alternator light is
> glowing dimly. I havent driven it very far but it seems the light will
> go out then maybe come on a bit later. I would presume alt. problems,
> but my after market amp guage is still showing charge and working
> normally. Am I about to have A failure or can I wait and see what
> developes?
> Bill 76 Edgemont
>

Bill,

Mine some times glows dimly when everything is OK. There is a reason for
this which I don't remember. Might be due to voltage drop across the diode
isolator which requires a higher alternator output voltage. It should be in
the early archives of GMCnet.

I have a feeling your amp gauge is correct.

Your light might be behaving like an idiot light.

Would be wise to check further before spending money.

Don Miller
75 Glennbrook project
Shenandoah Valley of Virginia
 
Its normal in some coaches for the light to glow and was covered in a recent
issue of GMC market place. you can but a diode in series with the light to
stop it, but why bother. If your gauge shows a charge and the voltage
across the battery terminals is OK than relax.

>
>> Just in the last few days I have noticed that my alternator light is
>> glowing dimly. I havent driven it very far but it seems the light will
>> go out then maybe come on a bit later. I would presume alt. problems,
>> but my after market amp guage is still showing charge and working
>> normally. Am I about to have A failure or can I wait and see what
>> developes?
>> Bill 76 Edgemont
>>
>
>
>Bill,
>
>Mine some times glows dimly when everything is OK. There is a reason for
>this which I don't remember. Might be due to voltage drop across the diode
>isolator which requires a higher alternator output voltage. It should be in
>the early archives of GMCnet.
>
>I have a feeling your amp gauge is correct.
>
>Your light might be behaving like an idiot light.
>
>Would be wise to check further before spending money.
>
>
>Don Miller
>75 Glennbrook project
>Shenandoah Valley of Virginia
>
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
Why all of this guessing??? If your battery voltage is fine and the engine
cranks over OK than the dim glow of your light is normal. Mine has been that
way since I bought the coach. Everything is fine with mine and may be with
yours. If its not broke don't touch it! Unless of course one wants to waste
money.

>Thanks to all. Will have batterys checked tho they are less than year old
>Bill 76 Edgemont
>

>
>> Sounds like your battery may be going south.
>> Dick 75 PB in Atlanta
>>

>> >Just in the last few days I have noticed that my alternator light is
>> >glowing dimly. I havent driven it very far but it seems the light will
>> >go out then maybe come on a bit later. I would presume alt. problems,
>> >but my after market amp guage is still showing charge and working
>> >normally. Am I about to have A failure or can I wait and see what
>> >developes?
>> >Bill 76 Edgemont
>> >
>
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
Don; and others

Thats kind of what I'm thinking. Guess I'll check batteries and voltage and
just watch things for awhile.
Bill 76 Edgemont

> > Just in the last few days I have noticed that my alternator light is
> > glowing dimly. I havent driven it very far but it seems the light will
> > go out then maybe come on a bit later. I would presume alt. problems,
> > but my after market amp guage is still showing charge and working
> > normally. Am I about to have A failure or can I wait and see what
> > developes?
> > Bill 76 Edgemont
> >
>
> Bill,
>
> Mine some times glows dimly when everything is OK. There is a reason for
> this which I don't remember. Might be due to voltage drop across the diode
> isolator which requires a higher alternator output voltage. It should be in
> the early archives of GMCnet.
>
> I have a feeling your amp gauge is correct.
>
> Your light might be behaving like an idiot light.
>
> Would be wise to check further before spending money.
>
> Don Miller
> 75 Glennbrook project
> Shenandoah Valley of Virginia
 
> Tom If it had always glowed and caused no problems I would'nt be concerned.
> The problem is it came on just a few days ago and the only thing I can think of
> that I did that had any bearing on it was that I had disconnected the air comp
> for rebuild and reconnected. Probably coincidence.
> Bill 76 Edgemont
>

>
> > Why all of this guessing??? If your battery voltage is fine and the engine
> > cranks over OK than the dim glow of your light is normal. Mine has been that
> > way since I bought the coach. Everything is fine with mine and may be with
> > yours. If its not broke don't touch it! Unless of course one wants to waste
> > money.
> >

> > >Thanks to all. Will have batterys checked tho they are less than year old
> > >Bill 76 Edgemont
> > >

> > >
> > >> Sounds like your battery may be going south.
> > >> Dick 75 PB in Atlanta
> > >>

> > >> >Just in the last few days I have noticed that my alternator light is
> > >> >glowing dimly. I havent driven it very far but it seems the light will
> > >> >go out then maybe come on a bit later. I would presume alt. problems,
> > >> >but my after market amp guage is still showing charge and working
> > >> >normally. Am I about to have A failure or can I wait and see what
> > >> >developes?
> > >> >Bill 76 Edgemont
> > >> >
> > >
> > >
> > >
> > >
> > >
> > Tom & Marg Warner
> > Vernon Center NY
> > 1976 palmbeach
> > "The beautiful Mohawk Vally"
 
Than you might clean all the connections on the battery and the ground wire
to the frame.

>
>

>
>> Tom If it had always glowed and caused no problems I would'nt be
concerned.
>> The problem is it came on just a few days ago and the only thing I can
think of
>> that I did that had any bearing on it was that I had disconnected the
air comp
>> for rebuild and reconnected. Probably coincidence.
>> Bill 76 Edgemont
>>

>>
>> > Why all of this guessing??? If your battery voltage is fine and the engine
>> > cranks over OK than the dim glow of your light is normal. Mine has been
that
>> > way since I bought the coach. Everything is fine with mine and may be with
>> > yours. If its not broke don't touch it! Unless of course one wants to waste
>> > money.
>> >

>> > >Thanks to all. Will have batterys checked tho they are less than year old
>> > >Bill 76 Edgemont
>> > >

>> > >
>> > >> Sounds like your battery may be going south.
>> > >> Dick 75 PB in Atlanta
>> > >>

>> > >> >Just in the last few days I have noticed that my alternator light is
>> > >> >glowing dimly. I havent driven it very far but it seems the light will
>> > >> >go out then maybe come on a bit later. I would presume alt. problems,
>> > >> >but my after market amp guage is still showing charge and working
>> > >> >normally. Am I about to have A failure or can I wait and see what
>> > >> >developes?
>> > >> >Bill 76 Edgemont
>> > >> >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > Tom & Marg Warner
>> > Vernon Center NY
>> > 1976 palmbeach
>> > "The beautiful Mohawk Vally"
>
>
>
>
>
Tom & Marg Warner
Vernon Center NY
1976 palmbeach
"The beautiful Mohawk Vally"
 
I think there was a service bullitin on this one. If someone has the book
handy maybe they can confirm this? I think it has to to with the voltage
drop on the battery isolator showing up at the "idiot light".

I have the problem and have always just ignored it.

Dave
73 Sequoia
 
There is one other condition that can cause the symptom of a dimly lit
idiot lamp. A GMCer replaced his alternator, and still had the dim glow
problem. He checked a diode that is supposed to eliminate this on some
production models. NO luck. He then discovered that his 10 AMP dash
instrument gauge fuse was blown. The fuse provides 12 volts to one side
of that lamp and if it is blown it does not have 12 volts there. When
the alternator starts putting out 15 volts there is a differential 15 - 0
and it gets an indication. Replace the fuse (or check wiring and grounds
to make sure you have 11.5 to 12 volts at the lamp and the glow should
cease, except when the alternator is not putting out 15 volts, which is
the way it is supposed to work. It was reported in GMCMN in March 98
page 5.
- --
"I do whatever my Rice Krispies tell me to..." John said.
 
You must log in or register to reply here.
GMCMI Fall 2026 Rally
Applied GMC

Share this page

Share this page
Top Bottom
Back