electrical system problem

[Peter Biskup]

I recently had a repair done, and looking at the electrical system, the tech determined: Batteries are receiving 60A charge from alternator continuously. Found batter isolator removed from system." Also stated that a voltage regulator within the alternator needs to be verified to be working correctly.

The wire from the alternator goes first to the left electrical thing, which the tech says is the suspect one. The closeup of that thing also faintly shows an outline of another larger, rectangular thing that used to be there, including 4 attachment bolts on the corners.

Any enlightenment that anyone can offer will be greatly appreciated!
Peter Biskup

1998 Beaver Monterrey 3004 (Magnum chassis)
Cat 3126 engine
NO inverter, propane generator

[Bill Lampkin]

I would keep that mechanic-it does look like a battery isolator has been removed and replaced with one or two solenoids (the thing that looks like a small round can with the wires connected.)

What was removed may have looked like this:

https://www.waytekwire.com/item/80046/Sure-Power-702-Multi-Battery/?gclid=Cj0KCQiA1pyCBhCtARIsAHaY_5cSd2lZV6oEax-nJL56dHyqBMNHUWVFQdhux52ARZ0oNmuCRpPd-xsaAmwGEALw_wcB

Many firms make battery isolators, Intellitec, Blue Sea Systems, you can do a search.

[Frank Bergamo]

Peter,

This is likely what was removed, https://www.motorcityreman.com/2-165.html?cmp=googleproducts&kw=2-165&gclid=EAIaIQobChMIlbv8lZyk7wIVlgytBh3XPgkMEAYYBSABEgJayvD_BwE  The alternator feed hooks to the middle terminal, the battery leads, coach/chassis, to each side of isolator, to isolate when parked. When running, the alternator feeds both sides, charging both sets of batteries. The solenoid that you have is most likely a 160 amp continuous duty solenoid that closes the circuit when ignition is turned on, charging both battery banks. With ignition off, batteries isolate from each other. Just two different way’s to achieve same objective. There should also be an Echo Charger, wired to each side of isolator, to charge chassis batteries when plugged into shore power or running generator. Hope this helps.

[Bill Lampkin]

Replaced my alternator last summer. Was told that it was a Leese-Neville Duvac type alternator, with a 12ga 'sense' wire from the alt to the batteries. The alternator senses the voltage at the battery (via the 12g wire) and charges the batteries accordingly. Diode type battery isolators (the blue box type) have a .7v voltage drop and thus may undercharge your batteries. Might be why the previous owner ripped the isolator out.

[Steve Huber Co-Admin]

Peter,
The un-modified layout and wiring is shown on pg 10 of the1996 Monterey wiring diagrams in Coach Assist.
Steve

[Carl Boger]

Peter,

Here is a picture of my isolator that I believe to be a original. Needs to be cleaned up a little! It is pretty much exactly the one that Frank posted a link for.  Hopefully this will help you with some of your questions.

[Carl Boger]

Frank,
Good point on the echo charger, but it is possible that he does not have one.  It was a option in 98, I had to add one to mine and wired it directly to the batteries.  Didn't even think about using the isolator, may switch it around to reduce the length of the wire runs.