Battery isolator problems

[84cruzer]

About a month ago the trouble began. While driving down the interstate i experienced a sudden failure of my alternator. Replaced it and the battery isolator, because of a crack in the gel. The rig ran for some time then it happened again. Replaced both the alternator and the battery isolator a second time. Now i have replaced the fuel pump as well thinking that the problem lies there somewhere. Now once again this time on a 4x4 trail my volts suddenly dropped off and the truck stalled. Had to swap batteries to get off the trail. Replaced the battery isolator..... again. I have a 1984 TLC with a 5.3L V8 swap 5 speed H55 transmission. Is it possible that heat from the headers could be the cause of the battery isolator failure? What should I be looking at now?

Currently have 14V at the back of the alternator and the battery isolator and it is charging the two batteries. WTF

Please help totally stumped right now.

Thanks

 

[sl33py]

what isolator are you running?

if it were that problematic i'd get rid of it until i found a better way. One of the marine mechanical combiners maybe to self jump? Depends what you are running now i guess.

Sucks - GL!

 

[fieldsken1]

maybe the isolator is to small in the amp department. i had one that was to small and i ended up putting a bigger one in

 

[84cruzer]

It was a surepower, i will have to get the exact model number when i get home.

 

[Kynot62]

Unless you have some specific reason to run an isolator, I would just eliminate it from the system. Toyota diesels have run two batteries from the start all without isolators.

If you want a more bulletproof way to isolate them just install a marine battery switch. This might help The Wagon Way This is how I have run dual batteries for years both in my 62 and in my BJ60

Tony

 

[lovetoski]

I find that with problems where there are potentially multiple causes, it's helpful (if possible) to simplify things. In your case I'd temporarily eliminate the isolator and dual battery. Run that way for awhile and see how things go.

On the isolator...I had one in my 80, and after 18 months it caused problems, so I got rid of it. In contrast in my 60 I had a VSR (voltage sensing relay) for quite a few years. That thing was bomber, no brainer simple, and worked like OEM. It's a very common approach in the marine land for multiple battery setups.

 

[sl33py]

I have a Hellroaring BIC and love it. about a year of use before became garage project truck... no issues to date.

I agree - eliminate and troubleshoot further. Good call on the amperage potentially exceeding the isolator - check the specs on your model isolator against the output of your alt.

 

[Kynot62]

I find that with problems where there are potentially multiple causes, it's helpful (if possible) to simplify things. In your case I'd temporarily eliminate the isolator and dual battery. Run that way for awhile and see how things go.

On the isolator...I had one in my 80, and after 18 months it caused problems, so I got rid of it. In contrast in my 60 I had a VSR (voltage sensing relay) for quite a few years. That thing was bomber, no brainer simple, and worked like OEM. It's a very common approach in the marine land for multiple battery setups.

Doug

Are you talking about an Automatic Charge Relay? Which are not uncommon in boats but I have never heard it called a voltage sensing relay. Realistically the boats I work on are far more complicated than a two battery system that is common to our wagons.

And to troubleshoot you do not need to remove the second battery as long as they are both in good shape and hold the same charge etc. As long as they are connected in parrellel the system just recognizes them as one large battery. Just pull the isolator and see if you still have problems

Tony

 

[ntsqd]

Tony, ACR and VSR are two mfg names for essentially the same component. Blue Seas calls it one thing and BEP calls it the other.

 

[Kynot62]

Thanks ntsqd, we pretty much only deal with Blue Seas, good products and they are only about an hour away from the boatyard.

Tony

 

[lovetoski]

Doug

Are you talking about an Automatic Charge Relay? Which are not uncommon in boats but I have never heard it called a voltage sensing relay. Realistically the boats I work on are far more complicated than a two battery system that is common to our wagons.

And to troubleshoot you do not need to remove the second battery as long as they are both in good shape and hold the same charge etc. As long as they are connected in parrellel the system just recognizes them as one large battery. Just pull the isolator and see if you still have problems

Tony

I'm not a boat guy, but I do know that boat's have complex electrical systems, and run in harsh environments, hence my personal preference for taking advantage of technology already proven to work in that environment. My local marine shop calls them VSR's but I defer to ntqsd as far as other nomenclature.

Simplification is the suggestion I was trying to make. Reduce complexity, evaluate performance, add back in one component at a time. This doesn't mean remove necessarily, just disconnecting serves the same purpose.

 

[ntsqd]

Concur, disconnect or by-pass to get to the simplest possible system. Then evaluate for correct operation and then add back in one component at a time - re-evaluating for correct operation as you go.

Also agree with leveraging marine technology. It's been proven to work and have large MTBF numbers. Which is not something that the more glamorously marketed "Overlander", "wheeler", & (ick) RV oriented products can claim.
I also think that designing the system to have alternate/redundant operation modes is a good idea. For instance own plan is to jumper an ACR/VSR across the terminals of marine battery bank switch. That way I can take it out of the system simply by turning the knob on the switch if I suspect that something is wrong with it or need a self jump-start or whatever.

 

[84cruzer]

Fusible Link?

I think this is my problem, is this a fusible link? The three wires to the right are completely fused together, and one of them is labeled Full Time Battery Power (ECM)

 

[sl33py]

that is *not* your FL, but may be what a PO did as your FL. Typically a FL will have green and white plugs with 3 wires between them - just off your positive battery terminal.

here's a 60's FL to see if you can find it or similar:

BUT i see you have a Vortec... so not sure if they would've kept this...

 

[Elbert]

I think this is my problem, is this a fusible link? The three wires to the right are completely fused together, and one of them is labeled Full Time Battery Power (ECM)

That looks to be a "but" connector.... you strip the ends of both wires...insert and then crimp the middle part with a pair of pliers. Some of them you heat up to make water tight...etc.