Skip to main content ↑ ↓
Topic: Moving isolator panel (Read 1209 times) previous topic - next topic

Re: Moving isolator panel

Reply #25 –
You should have numbers printed on each end of those wires.  Locate the B+ terminal on the alternator.  Check the wire number.  Match the other end of it.
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: Moving isolator panel

Reply #26 –
Tried that. Put one lead on the street-side terminal, other lead on the engine. No continuity. Tried the other terminal with the same result. If I can't find a better way, when it comes time to move the cable I'll disconnect one of the cables from the alternator and the cable from the alternator to the old isolator. Then I'll put a meter on both loose ends. If I have continuity I have the right one. If I don't, it must be the other one.

Brett, thanks for the tip about numbers. I'll see if I can see a number on the isolator end when I'm back under there tomorrow.

Re: Moving isolator panel

Reply #27 –
Quote from: kb0zke –
Tried that. Put one lead on the street-side terminal, other lead on the engine. No continuity. Tried the other terminal with the same result. If I can't find a better way, when it comes time to move the cable I'll disconnect one of the cables from the alternator and the cable from the alternator to the old isolator. Then I'll put a meter on both loose ends. If I have continuity I have the right one. If I don't, it must be the other one.

Brett, thanks for the tip about numbers. I'll see if I can see a number on the isolator end when I'm back under there tomorrow.
If you were checking the wires to ground with voltage setting the one with 12 volts is the output.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Moving isolator panel

Reply #28 –
After a bit of cleaning I found the numbers on the alternator cable at one terminal on the alternator, but couldn't read the other one. Wrote down the one I could see and crawled underneath. Cleaned that number, and it didn't match. Rats. Crawled back out, back inside and removed the other cable from the alternator. A bit more cleaning and I could read the number. Matched the end down below, so now I know which is the + cable.

I want to run the cable directly from the alternator to the new isolator by the shortest route, but I also need a long cable going from the new isolator down to the house batteries. I thought I'd save a few $$$ and use the existing cable from the alternator down to the old isolator panel. After cutting several cable ties, though, and only freeing up about 3 feet, I gave up. Tomorrow afternoon I'll take measurements over to O'Reilly's and get three new cables.

Once I'm done I'll post some pictures of how it all comes out. So far it is looking pretty good. One of the Laborers here has a label maker, so I'm going to see if I can get him to make labels for the solenoids, circuit breakers, and relays. That should make life a bit easier on the next person who has to work on any of this stuff. Yes, the labels will be in large print, and up where you can actually read them.

Re: Moving isolator panel

Reply #29 –
Making a cable to a length requires skill, tools and awareness.  Getting the right thickness-gauge of wire is straight forward.  Specifying the end-connectors is another thing.

We recommend never terminating cable with battery post squeeze connectors.  First there is a different terminal size for positive & negative posts.  We think that the best post connector is a "military style" that has place to bolt on a common spade cable end, with the single bolt hole.  And when the squeeze lead-type battery post connector fails, just replace the "military style" end and the cable does not need replacement.  We carry spares of "military" connectors.

Next is the orientation of the spade cable ends.  Battery cables are quite thick and not easily rotated to meet the place it is being terminated, whether a battery, starter, ground bolt, isolator, etc.  So know ahead the preferred direction of the end connector.  The shorter the cable, the harder to twist cable for a natural connection position.

End connectors can be crimped, soldered, bolted, etc.  I have even seen a shop take a hammer and vise to squeeze the end to the bare copper, to be clear, this method will not work, but yet it is offered if there is no other way.  Very long handle crimper or hydraulic crimper may be one of the best ways to terminate.  Putting terminal in a vise with cable entry end facing up, putting pieces of solder in entry, heating with torch, sticking bare cable into the solder and letting it cool is another good way. 

And there are different sizes of connector bolt holes, thickness and quality of terminals.

Re: Moving isolator panel

Reply #30 –
You should be able to find a shop that makes battery cables.  Best ones use marine grade (pre-tinned fine strand) wire.

Most West Marines have the proper wire, lugs and at least in our area you can use their proper sedge tool for free.
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: Moving isolator panel

Reply #31 –
Yesterday was our first trip since doing all of this work. All worked well. I still need to make and install labels (and post pictures here).

The project was actually pretty easy, since I had all new parts to work with. I installed them where I wanted them, leaving plenty of room (I thought) between things. The worst part, really, was the fact that most of the wires only came into the compartment at the foot of the bed about 6-8 inches, so I had to put a terminal block there and then extend each wire to where it needed to go. Naturally, after 23 years of being exposed to the elements and engine oil, some of the numbers on the wires were hard to read.

There is still somewhat of an alternator issue I think. When I start the engine, I see about 13.5 to just short of 14 volts on the dash volt meter. Turning the lights on drops the indicated voltage about 1 volt. After some time, maybe 30 minutes or so, the indicated voltage starts dropping to just below 12 volts without the lights. Turning the lights on drops it another volt, and turning them off brings it back.

Re: Moving isolator panel

Reply #32 –
David,

You need to verify voltage AT THE BATTERIES.  At the dash can be misleading.  Common for poor grounds at dash to artificially (and incorrectly) suggest voltage lower than actual. Dash lights/light switch and voltage drop is a symptom of this.

Let us know voltage at the batteries and what it reads at dash gauge with lights on, engine at 1000 RPM.  Also, read voltage at the ignition solenoid to the ground buss for comparison.  That will help identify the issue.
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: Moving isolator panel

Reply #33 –
Thanks, Brett. We'll do some checking this next week and report back.
 

Re: Moving isolator panel

Reply #34 –
Quote from: kb0zke –
Turning the lights on drops it another volt, and turning them off brings it back.

On Bluebirds, that is the first sign of a failing continuous duty solenoid.  Should be tied into the ignition block (on my Bluebird it is a panel under the drivers window.

I know different coach brand, but still something to investigate as a possible signal of a failing component. 

Dan - Full timing since 2009
2003 U320 40' Tag 2 slide