Alternator Replacement

[Don Bradner]

My alternator replacement job is done, I'm happy to say.

For memory refreshment, I had Alternator 1 with zero output, and Alternator 2
with max 50-amps and unable to maintain voltage with headlights on.

Replacing the top-front one (under the bed) was easy. That one was a 130-amp
Prestolite. After replacement, and with the power cables removed from the back
one, the engine was started and showed 100 amps on Alternator 1 at idle, zero on
Alternator 2. Voltage was above 13.5 and amps dropped quickly as the start drop
was replaced, even with the headlights on.

Replacing the back alternator was not easy at all. It sits under the A/C pump,
so I tried to drop it out the bottom, but there just wasn't room to make it. The
way the A/C pump is bracketed it was a B***h to remove, and similar to replace,
but I eventually got it done. The removed alternator has no apparent markings
anywhere, so I don't know what it was or its rating.

Running with the two new Leece-Neville 160-amp alternators the output after
startup is still 100 amps, shared equally between the two. I guess that makes
sense, but I had thought it would be higher. I wish I had a way to draw down the
batteries and still have enough to start the engine, so I could see if it would
show a higher charge rate.

Overall it was an interesting learning experience. I also replaced the belts on
Alternator 1, which showed some wear, but the others - alternator 2 and the A/C
pump - looked like new so I left them.


Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA

[Chuck Wheeler]

Don,

I believe that you will se the benefits of two alternators when you are
using a lot of the 12 volt systems on your coach such as moving out after
spending the night dry camping on the the batteries. When just charging the
batteries there are several things that will come into play limiting the
charging current. First you have the internal resistance of the batteries.
This increases as they age and the charging current will go down no matter
how much they are discharges. Then there is the resistance in the charging
circuit, wiring, ammeter shunts , etc.. Also no two regulators are exactly
the same. So one alternator will take the load first. It will be somewhat
balanced by the resistance in the wiring between the two. When I would
check out construction equipment with two alternators I would test one at a
time by disconnecting the battery wire from one alternator at a time.
Sometimes we would discover problems in one circuit. As I said at the
beginning the real benefit will be under heavy load. Just charging the
batteries this current will be limited by the alternator and wiring. Up to
the point that you overload the alternator the charging current will remain
the same for a certain amount of battery discharge no matter how large an
alternator you install.

- Chuck Wheeler -
82 FC 31 SB
Fort Worth, TX


_____

From: WanderlodgeForum@yahoogroups.com
[mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of Don Bradner
Sent: Sunday, March 04, 2007 11:07 PM
To: WanderlodgeForum@yahoogroups.com
Subject: [WanderlodgeForum] Alternator Replacement



My alternator replacement job is done, I'm happy to say.

For memory refreshment, I had Alternator 1 with zero output, and Alternator
2 with max 50-amps and unable to maintain voltage with headlights on.

Replacing the top-front one (under the bed) was easy. That one was a 130-amp
Prestolite. After replacement, and with the power cables removed from the
back one, the engine was started and showed 100 amps on Alternator 1 at
idle, zero on Alternator 2. Voltage was above 13.5 and amps dropped quickly
as the start drop was replaced, even with the headlights on.

Replacing the back alternator was not easy at all. It sits under the A/C
pump, so I tried to drop it out the bottom, but there just wasn't room to
make it. The way the A/C pump is bracketed it was a B***h to remove, and
similar to replace, but I eventually got it done. The removed alternator has
no apparent markings anywhere, so I don't know what it was or its rating.

Running with the two new Leece-Neville 160-amp alternators the output after
startup is still 100 amps, shared equally between the two. I guess that
makes sense, but I had thought it would be higher. I wish I had a way to
draw down the batteries and still have enough to start the engine, so I
could see if it would show a higher charge rate.

Overall it was an interesting learning experience. I also replaced the belts
on Alternator 1, which showed some wear, but the others - alternator 2 and
the A/C pump - looked like new so I left them.

Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA






[Non-text portions of this message have been removed]

[Gregory OConnor]

Don, (crosspost)For your test. Could you drain the battery bank below
12 and
than jump start the bus??? or run the bus and tax the inverter at a
major AC amp load. Even more load by running the inverter maxed, head
lights, and 12 v lights and appliances in BlueThunderRadioShack.

I always assumed demand from the inverter was the reason the alts
were so big. On the go camping with big alts and inverter was like
being hooked up to Shorepower or like running the Genset while going
down the road.

Assumption- While the bus is running the alts are called on to
directly resupply amps consumed from the batteries by inverter and
12v appliances up to the max of their rated output. Batteries were
not used unless demand was greater then alt supply.????????????

?Is major amp, quick battery recharge a battery damage thing? How do
the two alts divide up the amp load demand???

GregoryO'Connor
94ptRomolandCa
--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> My alternator replacement job is done, I'm happy to say.
>
> For memory refreshment, I had Alternator 1 with zero output, and
Alternator 2 with max 50-amps and unable to maintain voltage with
headlights on.
>
> Replacing the top-front one (under the bed) was easy. That one was
a 130-amp Prestolite. After replacement, and with the power cables
removed from the back one, the engine was started and showed 100 amps
on Alternator 1 at idle, zero on Alternator 2. Voltage was above 13.5
and amps dropped quickly as the start drop was replaced, even with
the headlights on.
>
> Replacing the back alternator was not easy at all. It sits under
the A/C pump, so I tried to drop it out the bottom, but there just
wasn't room to make it. The way the A/C pump is bracketed it was a
B***h to remove, and similar to replace, but I eventually got it
done. The removed alternator has no apparent markings anywhere, so I
don't know what it was or its rating.
>
> Running with the two new Leece-Neville 160-amp alternators the
output after startup is still 100 amps, shared equally between the
two. I guess that makes sense, but I had thought it would be higher.
I wish I had a way to draw down the batteries and still have enough
to start the engine, so I could see if it would show a higher charge
rate.
>
> Overall it was an interesting learning experience. I also replaced
the belts on Alternator 1, which showed some wear, but the others -
alternator 2 and the A/C pump - looked like new so I left them.
>
>
> Don Bradner
> 90 PT40 "Blue Thunder"
> Eureka, CA
>

[Chuck Wheeler]

Oops! Should have read this again after the spell checker got done with it!

- Chuck Wheeler -
82 FC 31 SB
Fort Worth, TX


_____

From: WanderlodgeForum@yahoogroups.com
[mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of Chuck Wheeler
Sent: Monday, March 05, 2007 9:45 AM
To: WanderlodgeForum@yahoogroups.com
Subject: RE: [WanderlodgeForum] Alternator Replacement



Don,

I believe that you will se the benefits of two alternators when you are
using a lot of the 12 volt systems on your coach such as moving out after
spending the night dry camping on the the batteries. When just charging the
batteries there are several things that will come into play limiting the
charging current. First you have the internal resistance of the batteries.
This increases as they age and the charging current will go down no matter
how much they are discharges. Then there is the resistance in the charging
circuit, wiring, ammeter shunts , etc.. Also no two regulators are exactly
the same. So one alternator will take the load first. It will be somewhat
balanced by the resistance in the wiring between the two. When I would
check out construction equipment with two alternators I would test one at a
time by disconnecting the battery wire from one alternator at a time.
Sometimes we would discover problems in one circuit. As I said at the
beginning the real benefit will be under heavy load. Just charging the
batteries this current will be limited by the alternator and wiring. Up to
the point that you overload the alternator the charging current will remain
the same for a certain amount of battery discharge no matter how large an
alternator you install.

- Chuck Wheeler -
82 FC 31 SB
Fort Worth, TX


_____

From: WanderlodgeForum@
yahoogroups.com
[mailto:WanderlodgeForum@
yahoogroups.com] On Behalf Of Don Bradner
Sent: Sunday, March 04, 2007 11:07 PM
To: WanderlodgeForum@
yahoogroups.com
Subject: [WanderlodgeForum] Alternator Replacement

My alternator replacement job is done, I'm happy to say.

For memory refreshment, I had Alternator 1 with zero output, and Alternator
2 with max 50-amps and unable to maintain voltage with headlights on.

Replacing the top-front one (under the bed) was easy. That one was a 130-amp
Prestolite. After replacement, and with the power cables removed from the
back one, the engine was started and showed 100 amps on Alternator 1 at
idle, zero on Alternator 2. Voltage was above 13.5 and amps dropped quickly
as the start drop was replaced, even with the headlights on.

Replacing the back alternator was not easy at all. It sits under the A/C
pump, so I tried to drop it out the bottom, but there just wasn't room to
make it. The way the A/C pump is bracketed it was a B***h to remove, and
similar to replace, but I eventually got it done. The removed alternator has
no apparent markings anywhere, so I don't know what it was or its rating.

Running with the two new Leece-Neville 160-amp alternators the output after
startup is still 100 amps, shared equally between the two. I guess that
makes sense, but I had thought it would be higher. I wish I had a way to
draw down the batteries and still have enough to start the engine, so I
could see if it would show a higher charge rate.

Overall it was an interesting learning experience. I also replaced the belts
on Alternator 1, which showed some wear, but the others - alternator 2 and
the A/C pump - looked like new so I left them.

Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA

[Non-text portions of this message have been removed]






[Non-text portions of this message have been removed]

[Don Bradner]

I would imagine that the wiring is a limiting factor, although hard to say for
sure. These are new AGMs, which have a low resistance compared to wet cells. The
most-likely primary cause for only getting 100 amps of charge is simply that the
batteries weren't particularly low, and therefore the voltage was quickly high.

On 3/5/2007 at 9:44 AM Chuck Wheeler wrote:

>Don,
>
>I believe that you will se the benefits of two alternators when you are
>using a lot of the 12 volt systems on your coach such as moving out after
>spending the night dry camping on the the batteries. When just charging
>the
>batteries there are several things that will come into play limiting the
>charging current. First you have the internal resistance of the batteries.
>This increases as they age and the charging current will go down no matter
>how much they are discharges. Then there is the resistance in the charging
>circuit, wiring, ammeter shunts , etc.. Also no two regulators are exactly
>the same. So one alternator will take the load first. It will be somewhat
>balanced by the resistance in the wiring between the two. When I would
>check out construction equipment with two alternators I would test one at a
>time by disconnecting the battery wire from one alternator at a time.
>Sometimes we would discover problems in one circuit. As I said at the
>beginning the real benefit will be under heavy load. Just charging the
>batteries this current will be limited by the alternator and wiring. Up to
>the point that you overload the alternator the charging current will remain
>the same for a certain amount of battery discharge no matter how large an
>alternator you install.
>
>- Chuck Wheeler -
>82 FC 31 SB
>Fort Worth, TX
>
>
> _____
>
>From: WanderlodgeForum@yahoogroups.com
>[mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of Don Bradner
>Sent: Sunday, March 04, 2007 11:07 PM
>To: WanderlodgeForum@yahoogroups.com
>Subject: [WanderlodgeForum] Alternator Replacement
>
>
>
>My alternator replacement job is done, I'm happy to say.
>
>For memory refreshment, I had Alternator 1 with zero output, and Alternator
>2 with max 50-amps and unable to maintain voltage with headlights on.
>
>Replacing the top-front one (under the bed) was easy. That one was a
>130-amp
>Prestolite. After replacement, and with the power cables removed from the
>back one, the engine was started and showed 100 amps on Alternator 1 at
>idle, zero on Alternator 2. Voltage was above 13.5 and amps dropped quickly
>as the start drop was replaced, even with the headlights on.
>
>Replacing the back alternator was not easy at all. It sits under the A/C
>pump, so I tried to drop it out the bottom, but there just wasn't room to
>make it. The way the A/C pump is bracketed it was a B***h to remove, and
>similar to replace, but I eventually got it done. The removed alternator
>has
>no apparent markings anywhere, so I don't know what it was or its rating.
>
>Running with the two new Leece-Neville 160-amp alternators the output after
>startup is still 100 amps, shared equally between the two. I guess that
>makes sense, but I had thought it would be higher. I wish I had a way to
>draw down the batteries and still have enough to start the engine, so I
>could see if it would show a higher charge rate.
>
>Overall it was an interesting learning experience. I also replaced the
>belts
>on Alternator 1, which showed some wear, but the others - alternator 2 and
>the A/C pump - looked like new so I left them.
>
>Don Bradner
>90 PT40 "Blue Thunder"
>Eureka, CA
>
>
>
>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>
>
>Yahoo! Groups Links
>
>
>

Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA

[Leroy Eckert]

Good deal. You are probably ok now . Mine will vary from 100 to 150 amps
depending on the load. I have learned not to get excited about it.

Leroy Eckert
1990 WB-40"Smoke N Mirrors"
Nicevile, FL




----- Original Message -----
From: Don Bradner
To: WanderlodgeForum@yahoogroups.com
Sent: Sunday, March 04, 2007 11:06 PM
Subject: [WanderlodgeForum] Alternator Replacement


My alternator replacement job is done, I'm happy to say.

For memory refreshment, I had Alternator 1 with zero output, and Alternator 2
with max 50-amps and unable to maintain voltage with headlights on.

Replacing the top-front one (under the bed) was easy. That one was a 130-amp
Prestolite. After replacement, and with the power cables removed from the back
one, the engine was started and showed 100 amps on Alternator 1 at idle, zero on
Alternator 2. Voltage was above 13.5 and amps dropped quickly as the start drop
was replaced, even with the headlights on.

Replacing the back alternator was not easy at all. It sits under the A/C pump,
so I tried to drop it out the bottom, but there just wasn't room to make it. The
way the A/C pump is bracketed it was a B***h to remove, and similar to replace,
but I eventually got it done. The removed alternator has no apparent markings
anywhere, so I don't know what it was or its rating.

Running with the two new Leece-Neville 160-amp alternators the output after
startup is still 100 amps, shared equally between the two. I guess that makes
sense, but I had thought it would be higher. I wish I had a way to draw down the
batteries and still have enough to start the engine, so I could see if it would
show a higher charge rate.

Overall it was an interesting learning experience. I also replaced the belts
on Alternator 1, which showed some wear, but the others - alternator 2 and the
A/C pump - looked like new so I left them.

Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA





[Non-text portions of this message have been removed]

[ronmarabito2002]

Not sure why you are pulling 100 amps, unless your batteries are
really low. After driving it a bit, it should go down to maybe 10 to
15 amps max. What kind of batteries do you have and how many for the
house and starting? If GEL cells, they should be at least 14.1 volts
during absorption and then drop to 13.5 volts for float voltage. The
"Ample Power Regulator" folks recommend 14.4 volts for absorption and
have not found this to cause gassing.

R.E. (Ron) Marabito, Dallas, TX 92WB40




--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> My alternator replacement job is done, I'm happy to say.
>
> For memory refreshment, I had Alternator 1 with zero output, and
Alternator 2 with max 50-amps and unable to maintain voltage with
headlights on.
>
> Replacing the top-front one (under the bed) was easy. That one was a
130-amp Prestolite. After replacement, and with the power cables
removed from the back one, the engine was started and showed 100 amps
on Alternator 1 at idle, zero on Alternator 2. Voltage was above 13.5
and amps dropped quickly as the start drop was replaced, even with the
headlights on.
>
> Replacing the back alternator was not easy at all. It sits under the
A/C pump, so I tried to drop it out the bottom, but there just wasn't
room to make it. The way the A/C pump is bracketed it was a B***h to
remove, and similar to replace, but I eventually got it done. The
removed alternator has no apparent markings anywhere, so I don't know
what it was or its rating.
>
> Running with the two new Leece-Neville 160-amp alternators the
output after startup is still 100 amps, shared equally between the
two. I guess that makes sense, but I had thought it would be higher. I
wish I had a way to draw down the batteries and still have enough to
start the engine, so I could see if it would show a higher charge rate.
>
> Overall it was an interesting learning experience. I also replaced
the belts on Alternator 1, which showed some wear, but the others -
alternator 2 and the A/C pump - looked like new so I left them.
>
>
> Don Bradner
> 90 PT40 "Blue Thunder"
> Eureka, CA
>

[Don Bradner]

My batteries are AGM, total 660AH, combined house and starting. Alternators
don't do Bulk/Absorption/Float three-stage charging, they are constant voltage.
In this case, 14.2. That does not mean that they would measure 14.2 across the
terminals, as they are pulled down by the current flow/low resistance when the
batteries are not fully charged.

When my batteries are fully charged, starting will still pull them down to about
12.7 volts (and that's only if there are just a few turns to start). The 100 amp
pull is immediately after that, and I mentioned that the amps dropped quickly as
the start drop was replaced and the voltage rose. I did not go to fully charged,
as I was just idling in the driveway.

On 3/6/2007 at 2:34 AM ronmarabito2002 wrote:

>Not sure why you are pulling 100 amps, unless your batteries are
>really low. After driving it a bit, it should go down to maybe 10 to
>15 amps max. What kind of batteries do you have and how many for the
>house and starting? If GEL cells, they should be at least 14.1 volts
>during absorption and then drop to 13.5 volts for float voltage. The
>"Ample Power Regulator" folks recommend 14.4 volts for absorption and
>have not found this to cause gassing.

Don Bradner
90 PT40 "Blue Thunder"
Eureka, CA

[ronmarabito2002]

Sorry Don. From the way I read your message, it sounded like you were
pulling a constant 100 amps. When you loose a regulator, you will
show 150 amps constant.

R.E. (Ron) Marabito, Dallas, TX 92WB40

--- In WanderlodgeForum@yahoogroups.com, "Don Bradner"
wrote:
>
> My batteries are AGM, total 660AH, combined house and starting.
Alternators don't do Bulk/Absorption/Float three-stage charging, they
are constant voltage. In this case, 14.2. That does not mean that they
would measure 14.2 across the terminals, as they are pulled down by
the current flow/low resistance when the batteries are not fully charged.
>
> When my batteries are fully charged, starting will still pull them
down to about 12.7 volts (and that's only if there are just a few
turns to start). The 100 amp pull is immediately after that, and I
mentioned that the amps dropped quickly as the start drop was replaced
and the voltage rose. I did not go to fully charged, as I was just
idling in the driveway.
>
> On 3/6/2007 at 2:34 AM ronmarabito2002 wrote:
>
> >Not sure why you are pulling 100 amps, unless your batteries are
> >really low. After driving it a bit, it should go down to maybe 10 to
> >15 amps max. What kind of batteries do you have and how many for the
> >house and starting? If GEL cells, they should be at least 14.1 volts
> >during absorption and then drop to 13.5 volts for float voltage. The
> >"Ample Power Regulator" folks recommend 14.4 volts for absorption and
> >have not found this to cause gassing.
>
> Don Bradner
> 90 PT40 "Blue Thunder"
> Eureka, CA
>