Battery isolator in 2000 Coachmen Santara 311SB?

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Start with the easiest first! I had the same problem and the fix was to remove the cables and clean the connections on the battery and the cable. Problem solved.

On my '98 Coachmen Santara, the isolator solenoid is on a tray next to the house battery underneath the entry steps.

I posted a picture of it and the associated components and circuitry (with labels) in this thread where I described some electrical upgrades I did last fall.

DrewE wrote:
On my '98 Coachmen Santara, the isolator solenoid is on a tray next to the house battery underneath the entry steps.

I posted a picture of it and the associated components and circuitry (with labels) in this thread where I described some electrical upgrades I did last fall.

Thanks!

So I finally got weather & time to check this out.
The thin wire coming to the isolator carries 14 volts with the engine off, and the emergency start button engaged.
With the engine running it in not carrying any voltage. There should be, shouldn't there?
It seems to me there must be a relay or something somewhere not working.
Any ideas?

glennestes wrote:
So I finally got weather & time to check this out.
The thin wire coming to the isolator carries 14 volts with the engine off, and the emergency start button engaged.
With the engine running it in not carrying any voltage. There should be, shouldn't there?
It seems to me there must be a relay or something somewhere not working.
Any ideas?

I think typically the emergency start switch (in this setup) is an SPDT switch with three wires connected to it. The common terminal of the switch is the lead to the isolator relay, the small wire you're talking of. The normally open wire comes from some circuit on the house 12V distribution panel. The normally closed wire is connected to the ignition circuit of the chassis, or something along those lines; on mine it's just the normal switched run circuitry. The basic idea is that when you press the switch, the house battery powers the relay to connect the two electrical systems since the chassis battery may be discharged too much to activate the relay.

At any rate, a good place to start checking things would be at the emergency start switch. It's possible there's some sort of a time delay or voltage sensing circuit or something that delays closing the relay when the engine is first started so that the chassis battery gets a chance to be recharged before the house battery is connected in (although, as I mentioned above, I don't believe my particular '98 Coachmen has anything this clever).