Battery Boost Solenoid Location? - 2007 Gulfstream Class C

thanks for your responses so far!

1. The "Boost" switch is a momentary SPST over the driver's head

2. The House Batteries (two T-105s) are fully charged as is the Chassis Battery

3. The House Batteries are located aft of the left side rear axle, in a compartment that
also has the "Distribution Panel". In the pics below, you can see that the Distribution
Panel mimics the Gulfstream diagram, except that the "Aux Start Solenoid" is not
there, instead there is a square black relay

4. Staring at these pics for a while, I think I will look behind this panel... it appears
the the black jacketed cable coming from the square hole and going to the lug on the
bottom of the fuse block just may be the "6ga Red" wire from the right terminal
of the solenoid ... I will start disassembling further tomorrow and will update

5. JaxDad, it certainly looks as you said, that the solonoid in the Distribution Panel
is only energized by the momentary boost switch, so that must be the Aux Start
relay (solenoid)... and that there must be a charge relay (solenoid) under the hood.

OP:
Where are your coach batteries located?

Interesting, Wire diagram say for a C's except Kodiak. Diagram looks the same as my wiring.
On my MH the solenoid/relay is located next to circuit breakers shown in the drawings.
Newer models than mine (2004) have a plastic cover for all the items in drawing. Looks like a black box about 12"X12".

If this can be of any help:

In our Itasca the auxiliary start solenoid (relay) is also the "charge" solenoid (relay).

Whenever the ignition switch is ON, this relay is also engaged so that the engine start battery and the two 12 volt coach batteries are all connected up in parallel with each other. This way the alternator is charging three 12 volt batteries at once whenever the engine is running.

Right next to our auxiliary start solenoid is another solenoid. This 2nd solenoid is the one that connects and disconnects the two coach batteries from the coach system by a switch that is on the wall right next to the entrance door.

Charge relay could be located in the under hood Ford fuse panel.
Does your rig have a box where the coach batteries are located. Some Winnebagos have the relays located behind a metal dead-front accessed by lifting step tread in the entry.

Unless your unit is different you should have two relays, not just one.

The first is the aux start relay, it is almost always located in or very close to the house battery.

The second relay, the charge relay, is almost always under the hood, usually slightly hidden by the chassis battery or tucked in front between battery and grill.

As was mentioned above though, if the house batteries are dead you won't hear the aux relay click and it may have shot the charge relay or blown a fuse.

First thing I'd suggest is to give the house batteries a checking over.

I have a 2007 Gulfstream C on a Ford 450 chassis. Noticed on one diagram that there is an AUX. start solenoid and the other diagram it is called a relay. There is only one on each diagram. Could it be that they are referring to a solenoid on the starter and there is no Aux. start solenoid? Maybe your house batteries are dead? You should know where the BOOST SWITCH is at. Let me know what you find, for I want to know also.