Battery Isolator Question

[hkyfsh]

I moved my Hawk into a new pickup and did the wiring myself based on what the old setup looks like. I have the isolator hooked up to the second battery in the truck with the white wire from the battery going to the gold terminal on the isolator and the other going to the camper hookup. Currently the camper is not on the truck but I went to use the truck today and the starting battery was dead but the second battery was full. Any chance that isolator caused this?

 

[hkyfsh]

Guess I should use the correct term. Can the self resetting circuit breaker under the hood that is installed with new campers possibly cause this with no draw on them since the camper is not on the truck?

 

[K7MDL]

Would need to know what model isolator you have to know what color terminals do what function on yours. There is no color standard to apply. You also stated the 2nd truck battery, so I assume you have this isolator (or is it really a solenoid device) between the 2 truck batteries under the hood, and you are tapping off one of the same terminals on the isolator as one of the batteries? Knowing exactly which battery is critical here.

Given your terms correction about a breaker instead of a isolator, do you actually have both, or just a breaker. If just a breaker, and you do have 2 truck batteries with no isolator under the hood, then the 2 batteries would be wired in parallel and if one dies, so should the other. Given you said only 1 died, I have to assume there is an isolator and likely a load in the camper dragged down a battery.

So hard to tell from your description what you have going on to offer much help. I can say that a breaker itself won't kill a battery, the load on the end of the wire would. Does your Hawk have a properly working isolator/solenoid device in it? Did you turn off the camper main power switch? You may need to do some voltage testing.

 

[hkyfsh]

Thanks for the reply. I do not have an isolator under the hood just the thermal breaker. The dual battery system is parallel and its the thermal circuit breaker that FWC installs under the hood with a new camper. I have a 2014 Hawk. The circuit breaker is hooked to the second battery and I misspoke about one battery being discharged and the other good. Both were discharged to the point that I had to charge them. The other relevant piece of information is that the camper was not on the truck or connected at the time of discharge. But the truck was sitting in the garage for a week without being run.

 

[ntsqd]

Late models have a lot of parasitic draws (clock memory, PCM memory, etc.). They're each very small, but it adds up to them not liking sitting for very long before the batteries go dead. If this is going to be the normal mode of use, sits for a while between uses, I'll suggest some sort of battery maintainer, be it a trickle charger or a small solar panel dedicated to the truck batteries. Solargizer used to be a decent name in the latter, no idea if they still are. Lots of names in the former, Ctek, BatteryTender, BatteryMinder are a couple.

 

[pawleyk]

I would be surprised if the camper wiring caused this. I don't think the breaker could cause any drain.

 

[billharr]

Thanks for the reply. I do not have an isolator under the hood just the thermal breaker. The dual battery system is parallel and its the thermal circuit breaker that FWC installs under the hood with a new camper. I have a 2014 Hawk. The circuit breaker is hooked to the second battery and I misspoke about one battery being discharged and the other good. Both were discharged to the point that I had to charge them. The other relevant piece of information is that the camper was not on the truck or connected at the time of discharge. But the truck was sitting in the garage for a week without being run.

If camper was not on truck it is not part of your problem. With the camper unhooked from the truck use a Multi Meter to check if there is a drain on your line to the camper. Check each side of the circuit breaker to be sure it is not going to ground. With the positive from the truck battery disconnected. Use the Ohm setting on the meter should show open circuit, if you show a drain something is going to ground. If you know how to use a meter should not take long to find. If you do not know how to use a meter here is a quick guide.

 

[hkyfsh]

OK took Bill's advice but not understanding how this actually works I'm not sure I understand what I was looking for, so I looked back at the pictures I took of how it was hooked up on the previous vehicle and maybe found my problem. I had the ground (black) wire from the camper hooked directly to the ground post on the battery, whereas on the previous vehicle it was bolted to the wall inside the engine compartment which is where the battery ground wire was also bolted.

I took a reading of both batteries this morning before I started this and they were both around 13.10 which was down from yesterday. Once I took the camper wiring off the auxiliary battery (so its not connected to anything), I retested and the batteries are at 13.27.

What if any issues would there be running the ground directly to the battery terminal, and second getting to the engine block where the ground is connected could be difficult. Reading back in some older posts it looks like I could ground it to a number of things in the engine compartment. Any advice?

 

[hkyfsh]

Guess that wasn't it. I totally took the camper wires out of the system and just during the day today from when I first posted voltage went from 13.27 to 13.02. Is it possible that it could be from just systems on the truck as mentioned above? Anyway thanks for all of the advice. I think i'll go to the dealer and see if they have any ideas.

 

[PokyBro]

Hkyfsh, being this is a new vehicle to, if it's not a brand new truck, have you considered the batteries starting to fail. How old are the batteries based on the sticker affixed to each battery?

I bought a used f250 diesel a couple years ago. As long as I drove it regularly, it started no problem. If it sat a week in cooler weather, I had one shot to start it, then the batteries were drained. After checking everything, looking for a drain on the system, having the alternator tested, I replaced the batteries, and, problem solved.

Something to consider.


Sent from my iPad using Wander The West

 

[hkyfsh]

Thanks PokyBro, it is a brand new truck. I will check out the battery manufacture date to see how old they are. Its a diesel with a dual battery system. Was going to disconnect the ground and run the voltage meter test on that to see how much is being drawn with the nothing being used. Was then gonna hook the camper wiring back up and do the same thing. Im not thinking its the camper wiring now but probably a parasitic draw. It doesn't look like it drained at all overnight so will keep checking.

 

[PaulT]

Guess that wasn't it. I totally took the camper wires out of the system and just during the day today from when I first posted voltage went from 13.27 to 13.02. Is it possible that it could be from just systems on the truck as mentioned above? Anyway thanks for all of the advice. I think i'll go to the dealer and see if they have any ideas.

A fully charged battery at rest overnight will likely be at 12.8 to 12.9 volts. When charger finishes, it will initially be at 13+ volts as the float voltage supplied by the charger is about 13.5-13.6 volts. Some if this terminal voltage will disipate over the next day or so, even without an external load pulling it down. Have a battery shop load test your batteries to verify that they are OK, but don't be concerned about voltages greater than 13 volts slowly diminishing to 12.8v or so.

Paul