Bohemian
Well-known member
Also, remember lead acid batteries should only be drank down by at most 50%. That is if you have a 49 amp-h battery, you should never use more than 20 amp-h of charge.
12V Draw While Driving? Request Peer Review.
- Thread starter StrongJava
- Start date
Also, remember lead acid batteries should only be drank down by at most 50%. That is if you have a 49 amp-h battery, you should never use more than 20 amp-h of charge.
StrongJava
Well-known member
Thanks again for those that have chimed in. I'm going to let this problem sit until I get my truck back and can test the 12V line from that to the 5er, and check for the fuse. I will also still call Fantastic tomorrow as I'm still not sure the fan/vent should be trying to pull a current when turned off, unless that is how the cover is kept down in automatic mode. However, even when the fan was put in manual mode, the system was looking for current according to the fuse panel.
For JanAndBill, the problem is that I've noticed after a day-long (6-8 hours) drive, my indicator in the coach shows the battery is close to being drained -- even though it was fully charged when departing -- with only the fridge being run in gas mode. As we often will overnight in a Wal-Mart parking lot, having a low charge on the battery becomes problematic when I need it to run the heat and the water pump, which frequently doesn't work in that condition.
This makes me think:
1) I may have a parasitic draw somewhere in the coach's 12V system,
2) The truck is not providing a charge to the trailer while driving, or it is even pulling current from the coach,
3) The indicator in the coach is wrong and symptom of the water pump not running all the time is unrelated.
My tests thus far have been aimed at trying to answer #1 as I believe it could lead to the symptoms I am seeing. I've read that tow vehicle systems frequently will only provide enough voltage to maintain a trailer battery, but will not charge it if it is drained or is under significant load; basically, the truck will only give excess capacity to the trailer.
As I said above, I'll do some tests with #2 when I get my truck back. And #3 may have to wait until we move again; next time I'll use the multimeter to check the battery charge instead of relying on the indicator in the coach.
Cheers, and Merry Christmas to all. May your holidays be filled with joy!
Tim
For JanAndBill, the problem is that I've noticed after a day-long (6-8 hours) drive, my indicator in the coach shows the battery is close to being drained -- even though it was fully charged when departing -- with only the fridge being run in gas mode. As we often will overnight in a Wal-Mart parking lot, having a low charge on the battery becomes problematic when I need it to run the heat and the water pump, which frequently doesn't work in that condition.
This makes me think:
1) I may have a parasitic draw somewhere in the coach's 12V system,
2) The truck is not providing a charge to the trailer while driving, or it is even pulling current from the coach,
3) The indicator in the coach is wrong and symptom of the water pump not running all the time is unrelated.
My tests thus far have been aimed at trying to answer #1 as I believe it could lead to the symptoms I am seeing. I've read that tow vehicle systems frequently will only provide enough voltage to maintain a trailer battery, but will not charge it if it is drained or is under significant load; basically, the truck will only give excess capacity to the trailer.
As I said above, I'll do some tests with #2 when I get my truck back. And #3 may have to wait until we move again; next time I'll use the multimeter to check the battery charge instead of relying on the indicator in the coach.
Cheers, and Merry Christmas to all. May your holidays be filled with joy!
Tim
travelin2
Pennsylvania Chapter Leaders-retired
Regarding your comment about the TV not be able to charge the battery...I had an instance early in our ownership of our BH during a week long dry camp. 1 of my 2 batteries crapped out and became a parasite to the other leaving us with no power one night. After discovering I had only 1 good battery and no other way to charge it I plugged into my TV. Not only could I power the coach but in a couple hours I had that one battery back to full charge. We were able to enjoy the rest of our stay without having to run into town from our USFS campsite.
Sent from my iPhone using Tapatalk
Oregon_Camper
Well-known member
You only have 1 battery...correct?
How old this battery?
Perhaps you just have a battery that can no longer hold a good charge or even take a good charge from the low amps off the truck.
How old this battery?
Perhaps you just have a battery that can no longer hold a good charge or even take a good charge from the low amps off the truck.
StrongJava
Well-known member
Correct, only one battery, and it is one year old. I had it tested at a local RV place (actually two places in the last two months) and they said it was good. But, I realize replacing the battery is an option.
And, through more research, I now understand the merit of @Bob&Patty's approach to testing the 12V system. I'll work that approach tomorrow.
Cheers, Tim
And, through more research, I now understand the merit of @Bob&Patty's approach to testing the 12V system. I'll work that approach tomorrow.
Cheers, Tim
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Thanks Bob!
Bob&Patty
Founders of SoCal Chapter
JB, its the way we test for a parasitic drain in cars and trucks. BTW, GM techs do know some helpful things. As I said you have let everything that can drain a battery power down. You will see it on the meter. "Keep a live memory", things like radios. ECM's, BCM's, Trans control module's, etc,etc, will drain a battery if they go wacko. Most of these things will draw about 1/2 milliamp for up to 5 minutes as they power down.. Our trailers have several of the these things drawing current all the time. The most common things I found were a rear dome lamp was left on, hard to see from the front in the day time and guess what...with a dead battery the light was not on. 9 times out if 10...it was "pilot error".
I had this issue with my TV. If it sat for a week...the batteries would be dead. It was the "auto leveling" air bag system. Come to find out, it would check for level every 45 seconds and was drawing .5 amps. Like a dumbie, I refused to drill a hole in my new truck firewall to have it only work on ignition on only. Moral of that story....read the instructions.
I had this issue with my TV. If it sat for a week...the batteries would be dead. It was the "auto leveling" air bag system. Come to find out, it would check for level every 45 seconds and was drawing .5 amps. Like a dumbie, I refused to drill a hole in my new truck firewall to have it only work on ignition on only. Moral of that story....read the instructions.
JanAndBill
Well-known member
All good comments but backup to the OP's post. "I've noticed that the battery was low AFTER driving". The OP also left the trailer unhooked for a longer period with no significant draw on the battery. That would lead me to look at circuits involved when towing including the TV. The other thing that I apparently missed is the frequency of this discharge. Does it happen every time or was it a one time occurrence?
StrongJava
Well-known member
Let me start by saying that four weeks is a long time to let a thread go that I STARTED. I did not realize so many people had continued to chime in, and I apologize for my tardiness. We had the trailer simply parked for awhile over the holidays or have been steadily on shore power. However, we're heading back to San Antonio for a spell, and the problem I experienced tonight when I pulled into the Wal-Mart parking made me realize I need to make this a priority again.
So, let me back up first. About a week ago we pulled into a spot near Gila Bend, AZ, where we had to dry camp for a night. I decided before opening the coach up to disconnect the truck and test the battery voltage and let it run the slides. I don't recall the exact voltage on the battery, but it was acceptable. Then I tried to run the slides they were not getting good force. So, I plugged the 7-wire back into the truck and ran the slides. All seemed fine. I left the truck connected so we'd have power over night. BTW, I normally leave the truck electrically connected when we overnight, and I have run down the truck's battery. I wonder now if I've been dodging a bullet.
Back to tonight. And this to me gets really weird, but perhaps someone with a lot more vehicle experience will get it. I parked the rig and put down the landing gears and stabilizers before shutting off the truck. Unfortunately, my memory is sketchy as this stage but I think I disconnected the 7-wire from the truck and stepped into the coach. I push the test button on the console and found the battery meter was showing full. I thought all was good. I then ran the slides out. They seemed to run pretty smooth albeit a bit slow (I added more lithium grease to the tracks during the last stop). If I had not disconnected the 7-wire earlier, I know I then stepped outside and disconnected it then. At that point, my wife tried to turn on the lights in the coach and there was zero power inside. Not lights on the console and the fridge was out, etc. So, I plugged back into the truck and 12V power came back to the coach. I then disconnected the battery leads to the coach and tested the voltage across the battery terminals: 12.94V -- acceptable. I hooked the battery leads back up, and then unplugged the 7-wire again. The power in the coach stayed on!
What on earth could cause this behavior? I was confused before, and am even more so now!
Thanks in advance for any thoughts.
Tim
p.s., When I get to a better Internet connection, I'll watch the video and then follow the procedures at the first opportunity.
p.p.s., I had tested the voltage output from the truck and found acceptable force coming out to the trailer. I have not found the fuse yet.
So, let me back up first. About a week ago we pulled into a spot near Gila Bend, AZ, where we had to dry camp for a night. I decided before opening the coach up to disconnect the truck and test the battery voltage and let it run the slides. I don't recall the exact voltage on the battery, but it was acceptable. Then I tried to run the slides they were not getting good force. So, I plugged the 7-wire back into the truck and ran the slides. All seemed fine. I left the truck connected so we'd have power over night. BTW, I normally leave the truck electrically connected when we overnight, and I have run down the truck's battery. I wonder now if I've been dodging a bullet.
Back to tonight. And this to me gets really weird, but perhaps someone with a lot more vehicle experience will get it. I parked the rig and put down the landing gears and stabilizers before shutting off the truck. Unfortunately, my memory is sketchy as this stage but I think I disconnected the 7-wire from the truck and stepped into the coach. I push the test button on the console and found the battery meter was showing full. I thought all was good. I then ran the slides out. They seemed to run pretty smooth albeit a bit slow (I added more lithium grease to the tracks during the last stop). If I had not disconnected the 7-wire earlier, I know I then stepped outside and disconnected it then. At that point, my wife tried to turn on the lights in the coach and there was zero power inside. Not lights on the console and the fridge was out, etc. So, I plugged back into the truck and 12V power came back to the coach. I then disconnected the battery leads to the coach and tested the voltage across the battery terminals: 12.94V -- acceptable. I hooked the battery leads back up, and then unplugged the 7-wire again. The power in the coach stayed on!
What on earth could cause this behavior? I was confused before, and am even more so now!
Thanks in advance for any thoughts.
Tim
p.s., When I get to a better Internet connection, I'll watch the video and then follow the procedures at the first opportunity.
p.p.s., I had tested the voltage output from the truck and found acceptable force coming out to the trailer. I have not found the fuse yet.
StrongJava
Well-known member
Thanks again, Dan.
The connections to the buss bar look solid, and we had cleaned the battery terminals. However, I just started pealing back some of the insulation and I still see a lot of corrosion. So, I think I'll work on replacing those battery leads. It can't hurt.
I was looking through the 12V diagrams but I'm not sure I see a battery disconnect in my coach (2008 BH 3670RL). I'm going to step outside and look again, but is it someplace unique?
Now this is interesting. I'm poking around in the battery compartment flexing the leads and searching again for the little reset button I've read about. I finally found it and pushed it. It feels very soft with a weak spring action. Is this how it should feel or should it be more like a GFCI button? In any case, during my messing about in the battery box, I killed the 12V to the coach. Plugged the coach back into the truck to restore power. Disconnected again and power remained on. I pushed the reset button some more and wiggled the battery leads, but wasn't able to reproduce the outage.
Does it make sense to replace the buss bar post that has the reset button?
Tim
The connections to the buss bar look solid, and we had cleaned the battery terminals. However, I just started pealing back some of the insulation and I still see a lot of corrosion. So, I think I'll work on replacing those battery leads. It can't hurt.
I was looking through the 12V diagrams but I'm not sure I see a battery disconnect in my coach (2008 BH 3670RL). I'm going to step outside and look again, but is it someplace unique?
Now this is interesting. I'm poking around in the battery compartment flexing the leads and searching again for the little reset button I've read about. I finally found it and pushed it. It feels very soft with a weak spring action. Is this how it should feel or should it be more like a GFCI button? In any case, during my messing about in the battery box, I killed the 12V to the coach. Plugged the coach back into the truck to restore power. Disconnected again and power remained on. I pushed the reset button some more and wiggled the battery leads, but wasn't able to reproduce the outage.
Does it make sense to replace the buss bar post that has the reset button?
Tim
justafordguy
Well-known member
Sounds like you have a loose ground wire to the frame. I would also clean every breaker connection on the buss bar and tighten the nuts up good.
danemayer
Well-known member
The mini breaker on the buss bar that has the manual reset connects the battery to the fuse box/Power Converter. It generally has a soft feel. If the breaker was tripped or malfunctioning, battery power wouldn't get to the interior lights and appliances. But neither would power from the tow vehicle. So it would seem that's ok.
The intermittent nature of the power from the battery argues that you don't have a reliable path from one or both battery terminals. Most Bighorns have a battery cutoff switch, but I don't know if that goes back to 2008 models.
If everything looks good on the wiring from positive terminal to the buss bar, I'd check the negative terminal to ground. You may have to take town the rear wall of pass through storage to find the ground connection.
The intermittent nature of the power from the battery argues that you don't have a reliable path from one or both battery terminals. Most Bighorns have a battery cutoff switch, but I don't know if that goes back to 2008 models.
If everything looks good on the wiring from positive terminal to the buss bar, I'd check the negative terminal to ground. You may have to take town the rear wall of pass through storage to find the ground connection.
StrongJava
Well-known member
My next project for our next stop. Thanks again for the help.
StrongJava
Well-known member
I have checked the connections to the buss bar, and took out the back wall to look at the grounds. All looks clean and tight with the exception of the aforementioned leads to the battery itself.
Please look at my new thread which I suspect is related: Landing Gear Problems (Electrical and Mechanical)
Please look at my new thread which I suspect is related: Landing Gear Problems (Electrical and Mechanical)
