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Topic: Does anyone know what this is? (Read 613 times) previous topic - next topic

Does anyone know what this is?

This should be self explainatory for someone who knows what it is.
How do I know if the selenoid looking thing towards the bottom right is working in this application?
Carl Sandel
1991 36' U280
Northern Michigan

Re: Does anyone know what this is?

Reply #1 –
Carl, This is your battery isolator.  The Solenoid looks to be corroded but may still be working.  If It was Me I would replace it now, not when you have to.
On lower left is a relay, probably the AC compressoer relay.  These are cheap and I carry two of them as insurance.
Looks like all the cable and wire connections could use a good bit of cleaning up.
To verify solenoid op, use a Volmeter, should have voltage both sides when engaged.
Gary B

Re: Does anyone know what this is?

Reply #2 –
Carl, Now that I look  at this photo Twice I wonder what the two wires that are on the left go to ? It LOOKS like this is where another solenoid was mounted and someone has screwed them down to the mounting plate.
Should ( or usually is ) be two solenoids, one is start solenoid and the other is boost.
Gary B

Re: Does anyone know what this is?

Reply #3 –
Gary is correct.  That large rectangular box with heat sinks is the diode-based battery isolator.

Guessing, but probably center lug to alternator and the two outer lugs to chassis and house battery.

Brett
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Does anyone know what this is?

Reply #4 –
Carl, Took a THIRD look at that isolator,  looks like the two wires in the lower left are attached to a SELF RESETTING Circuit Breaker.  Would have to get a closer look to be sure, at any rate the connections could use some cleaning up.  This is in an awkward position but one way is to remove one wire at a time and using plumbers tape ( emery paper ), clean each connection, use a wire brush on the posts, and replace each one as you clean it up.  Some dieelectric Grease would not hurt either.
Gary B

Re: Does anyone know what this is?

Reply #5 –
Nice! Thanks Gary. I'm going to get right after ALL the connections on this and everything else right after the 4th.
Carl Sandel
1991 36' U280
Northern Michigan