Thoughts on powering supplemental vacuum pump

[mark grady]

Heinz --

I think your switch on the vac booster pump is right for you, but...

One other thought I had is that GM products have an accessory feed bus that
cuts power to selected electrical accessories when the key is twisted and
held in the start position.

That would seem to have most of the same benefits as the manual switch if
other GMC'rs were looking for alternative ways to power the unit.

You turn the key on, the vac pump runs if needed, then it stops while
cranking the engine. That makes the maximum output of the battery available
to the starter and ignition.

Release the key, the engine is running. The booster pump is satisfied that
vacuum is present and it doesn't run anymore.

Just a thought.

Mark Grady

> -----Original Message-----
> From: owner-gmcmotorhome
> [mailtowner-gmcmotorhome]On Behalf Of Heinz
> Wittenbecher
> Sent: Tuesday, February 16, 1999 12:36 PM
> To: gmcmotorhome
> Subject: Re: GMC: View from the Pit... and new Toy add-on in progress
>
>
> Good point Emery.
> I think this is going to one of those "as many answers as members of the
> list thingies" and that's what's so nice about the list. Soak up all the
> info and then make ones own decision based on a multitude of information.
>
> Until the first time the BVD's get dirty I'm goint to try and add
> the switch
> to my top-of-the hill checklist, i.e. tap the brakes, check the switch for
> "armed" position.
>

 

[heinz wittenbecher]

Excellent thought Mark.

That's the route I'm going to go should a rewire become necessary due to
brain-dead syndrome

Heinz

>Heinz --
>
>I think your switch on the vac booster pump is right for you, but...
>
>One other thought I had is that GM products have an accessory feed bus that
>cuts power to selected electrical accessories when the key is twisted and
>held in the start position.
>
>That would seem to have most of the same benefits as the manual switch if
>other GMC'rs were looking for alternative ways to power the unit.
>
>You turn the key on, the vac pump runs if needed, then it stops while
>cranking the engine. That makes the maximum output of the battery available
>to the starter and ignition.
>
>Release the key, the engine is running. The booster pump is satisfied that
>vacuum is present and it doesn't run anymore.
>
>Just a thought.
>
>Mark Grady
>
>> -----Original Message-----
>> From: owner-gmcmotorhome
>> [mailtowner-gmcmotorhome]On Behalf Of Heinz
>> Wittenbecher
>> Sent: Tuesday, February 16, 1999 12:36 PM
>> To: gmcmotorhome
>> Subject: Re: GMC: View from the Pit... and new Toy add-on in progress
>>
>>
>> Good point Emery.
>> I think this is going to one of those "as many answers as members of the
>> list thingies" and that's what's so nice about the list. Soak up all the
>> info and then make ones own decision based on a multitude of information.
>>
>> Until the first time the BVD's get dirty I'm goint to try and add
>> the switch
>> to my top-of-the hill checklist, i.e. tap the brakes, check the switch
for
>> "armed" position.
>>
>
>

 

[bartz paul]

Heinz:

Another good reason for using a switch is so that pump can be turned off so
as not to run down the battery as the vacuum leaks down over time and the
pump cycles on to reestablish the pressure.

Paul Bartz

From: Mark Grady [mailto:mgrady]
Sent: Tuesday, February 16, 1999 12:57 PM
Subject: GMC: Thoughts on powering supplemental vacuum pump

Heinz-
I think your switch on the vac booster pump is right for you, but...
One other thought I had is that GM products have an accessory feed bus that
cuts power to selected electrical accessories when the key is twisted and
held in the start position.
That would seem to have most of the same benefits as the manual switch if
other GMC'rs were looking for alternative ways to power the unit.
You turn the key on, the vac pump runs if needed, then it stops while
cranking the engine. That makes the maximum output of the battery available
to the starter and ignition.
Release the key, the engine is running. The booster pump is satisfied that
vacuum is present and it doesn't run anymore.
From: owner-gmcmotorhome
On Behalf Of Heinz
Wittenbecher
Sent: Tuesday, February 16, 1999 12:36 PM
Subject: Re: GMC: View from the Pit... and new Toy add-on in progress
Good point Emery.
I think this is going to one of those "as many answers as members of the
list thingies" and that's what's so nice about the list. Soak up all the
info and then make ones own decision based on a multitude of information.
Until the first time the BVD's get dirty I'm goint to try and add the switch
to my top-of-the hill checklist, i.e. tap the brakes, check the switch for
"armed" position.