Last year I replaced both batteries on my FG because they were dead when I went to pick it up at the storage yard. Went to pick it up at the storage yard yesterday and batteries were so dead they didn't even power the dash lights. It had been in the yard about 4 weeks. Prior to the last time I drove it, it had been in the yard for about 6 months and fired right up when I turned the key. I haven't done a draw test yet on the system to see if something is drawing power with the key off, but the batteries don't seem to be taking a charge so it looks like the new batteries are now defunct. Anyone have any experience with these kinds of electrical problems? It seems like there's an intermittent draw on the batteries with the key off.
Batteries/electrical diagnostic question
- Thread starter kerry
- Start date
Stumpalump
Expedition Leader
Charge batts. Disconect red terminal from bat and put your DVM across the gap and set it for amps. That will tell you what the amp draw is. Pull fuses one at a time untill amps go to Zero. Now you know where to start looking. It could also be drawing down from your alternator or anyplace else but you should get the idea.
GroupSe7en
Adventurer
batts
It could be the batteries themselves. Sometimes when they discharge down below a certain point they never come back. They may appear to have a full charge in them but, for example, where they may have had 100ah initially, they might only have 5ah after the fatal discharge.
I'm currently fighting battery wars on the trailer - arrrgh!
Good luck
It could be the batteries themselves. Sometimes when they discharge down below a certain point they never come back. They may appear to have a full charge in them but, for example, where they may have had 100ah initially, they might only have 5ah after the fatal discharge.
I'm currently fighting battery wars on the trailer - arrrgh!
Good luck
Only drawing .35 amps with the key off and camper unplugged. .40 amps with the camper plugged in. Those numbers are normal I believe. However, I think I may have located the source of the problem, once I disconnected the positive post to take the reading, I reattached the battery charger directly to the positive post without the cable attached. The batteries immediately showed they were taking a charge. This leads me to conclude that the was a problem with the positive post connection. There was corrosion on it. I'll clean it up and reassemble and see what happens.
Yes, the battery terminal is poorly designed. Don't know if mine is OE or not but it's a lead clamp to the post with a single bolt sticking up from it with at least three heavy cables and a couple of lighter wires attached to the bolt. Lots of opportunity for poor connections with all those surfaces stacked on top of each other. Took mine apart, cleaned up all surfaces with a wire brush and a liquid cleaner and reassembled. It's working but I anticipate future problerms again.
One thing that has happened to me a few times is this: I think the batteries are dead because the truck won't start, dash lights won't come on, etc. But then the voltage on the batteries looks okay. So I just "jiggle" the connections a bit, especially the smaller wires, and then everything is fine - the truck starts right up like nothing ever happened.
I was thinking maybe I need to clean the dirt off the battery connections, they are pretty dirty.
I was thinking maybe I need to clean the dirt off the battery connections, they are pretty dirty.
dhackney
Expedition Leader
Kerry,
I faced the same challenge with a lot of cables attaching to the start bank, so I added marine buss bars to the system. This allows one connection to the start bank and a clean connection design for all other circuits.
Always use dialectric grease for every electrical connection.
Photos here:
http://www.hackneys.com/mitsu/photos/buildup_album_27/index4.htm
(The first two shots are Steph organizing all the receipts for the truck build. Note that we measured them in inches rather than dollars...
)The small coiled wire in the post-buss bar shots is a jumper cable for our dirt bikes.
And, BTW, NEVER work on a hot, smoking battery, even when you are trying to catch a ferry. I know of a guy who was blinded by an exploding battery in those exact circumstances (minus the ferry).
Doug
whatcharterboat
Supporting Sponsor, Overland Certified OC0018
Hi Kerry and of course Doug . BTW Good job on the postive distribution busses Doug.
Just to throw in my little bit and in case your truck isn't cabled this way already >> (and I should add IMO) whenever you have batteries in parallel as you do with the Fuso start batteries, then I think the positive leads to the truck should be on one battery and the main earth should come off the other battery or off the last battery in the parralel chain if there is more than 2 such as you would have with a big house bank. This should help reduce the chance of one battery getting more or less charge than the other through poor connections.
Oh and so you don't end up with poor connections in the first place, always use something like CRC Battery Terminal Protector Spray or even CRC Electro Shield or some thing that will not just seal the terminals and posts but hang on with heat and not load up with dust. So Vaseline or other similar light greases would not be my first options.
Just to throw in my little bit and in case your truck isn't cabled this way already >> (and I should add IMO) whenever you have batteries in parallel as you do with the Fuso start batteries, then I think the positive leads to the truck should be on one battery and the main earth should come off the other battery or off the last battery in the parralel chain if there is more than 2 such as you would have with a big house bank. This should help reduce the chance of one battery getting more or less charge than the other through poor connections.
Oh and so you don't end up with poor connections in the first place, always use something like CRC Battery Terminal Protector Spray or even CRC Electro Shield or some thing that will not just seal the terminals and posts but hang on with heat and not load up with dust. So Vaseline or other similar light greases would not be my first options.
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