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mxbmx930 · 05-24-2009, 03:17 PM

So I got some new batteries the other day. 2 6-volt Trojan t-105 plus batteries to replace the 2 12 volt autoparts store size 27 deep cycle and now my liftgate on the back of my funmover won't work.

Under my compartment I have three wires. One positive that goes to everything which has a jumper wire to a circuit breaker that goes back to my liftgate. And 2 negatives. One to the coach and one to the liftgate. It's a Thieman TVL series by the way. So I connected the battery like I read online to make it 12 volt into the coach and it all works just fine in the coach. I hooked the positive up to battery #1, Then I hooked the coach and liftgate negative up to the negative on battery #2. then the 2 batteries are connected through a single 2 gauge wire from one positive to one negative.

Liftgate is not working though. Everything else is fine.

Gary RVRoamer · 05-24-2009, 03:38 PM

There is no reason to have two negatives and only one positive. I'm thinking you have another positive under there somewhere.

mxbmx930 · 05-24-2009, 05:00 PM

Well the one positive goes into a splitter that has mulitple positives coming out and One of them goes into a circuit breaker which then follows the 2nd negative wire to the back where the liftgate is.

GaryKD · 05-24-2009, 06:01 PM

Hi mxbmx930,
The only thing left to do is trace the 12 VDC to where you loose it.

I know this might sound basic, but the batteries are connected in series? Battery #1 positive terminal is connected to the coach. Battery #1 negative terminal is connected to the positive terminal of battery #2. Battery #2 negative terminal is connected to ground.

Worst case scenario might be that 12 VDC gets to the lift gate. The two 6 VDC batteries may not have enough power to operate the gate. The 2 12 VDC batteries, connected in parallel, doubled their amp hour capacity to an appliance. The two 6 VDC batteries connected in series double the VDC (from 6 VDC to 12 VDC) but the amp hour capacity remained at what ever each battery is rated.

mxbmx930 · 05-24-2009, 11:10 PM

yep, that is how i connected the batteries. I was wondering if maybe the 2 6 volt couldn't power it but when we bought the thing it came one 12 volt deep cycle marine/rv battery and that powered the lift gate.

GaryKD · 05-25-2009, 08:52 AM

Hi mxbmx930,

If it was me, I'd start at the lift gate and check the power. If you have 12 VDC at the gate, then there may not be enough power from the batteries. If there is no or only 6 VDC power at the gate, then work toward the batteries until you find where it is being lost. Make sure it's 12 VDC at the lift gate. When working with 6 VDC batteries, it is real easy to get only 6 VDC out to some of the appliances. Because the coach was purchased used, one does not know what has happened between the factory and your current problem.

mxbmx930 · 05-25-2009, 12:42 PM

Quote:

Originally Posted by GaryKD

Hi mxbmx930,

If it was me, I'd start at the lift gate and check the power. If you have 12 VDC at the gate, then there may not be enough power from the batteries. If there is no or only 6 VDC power at the gate, then work toward the batteries until you find where it is being lost. Make sure it's 12 VDC at the lift gate. When working with 6 VDC batteries, it is real easy to get only 6 VDC out to some of the appliances. Because the coach was purchased used, one does not know what has happened between the factory and your current problem.

I am going to check one more thing and then see if I can find a 12 volt battery to hook up to the liftgate by itself. I was really hoping these batteries would work but maybe not. Everything thing in the coach is great. It has to be the hook up cause it worked before. btw, I did purchase the coach new if that matters.

How do I go about checking the power at the liftgate? Problem is I am out in california at a motocross track and don't have a lot of tools and stuff. I could get to an autoparts store if need be.

GaryKD · 05-25-2009, 12:55 PM

Hi mxbmx930,
Find the wires that go to the lift gate. Determine where they connect to the lift gate motor. You'll need a meter to measure the VDC. I prefer the analog kind instead of the digital. This is because you'll need to measure to the first place to the right of the decimal point. Most digital meters do not to this.

When measuring the VDC, you want a reading of 12.6 or above. This would mean the batteries are at full charge. An approximate of full charge capacity is:
12.6 + 100%
12.5 = 90%
12.4 = 80%
12.3 = 70%
12.2 = 60%
12.06 = 50%
11.9 = 40%
11.75 = 30%
11.6 = 20%
11.3 = 10%
10.5 = 0%

If the batteries are not at full charge, it puts them at a disadvantage for this test.

mxbmx930 · 05-25-2009, 02:21 PM

Okay I found the problem. I went tracing the lines in more detail to see what i need to do and guess what. I found a negative in the back that looked like it was coming from inside the panel so I traced back and found out the positive for the lift was not marked properly. the positive is a black wire and looked like it was a negative, and there was a positive red wire that went back with it but ran into a different box. Confused me cause every positive is red and there was only 2 black wires, one being the coach negative so I assumed that was a negative too.

I guess when they took the battery (to avoid the core charge) I didn't check to see that was positive. So when i went to hook it up myself I assume that black wire was a negative as with the coach. Thanks for all the help, I might have not found it if I didn't go tracing the lines.

GaryKD · 05-25-2009, 05:37 PM

It is always nice when the fix costs nothing but time. This could have been a lot worse. Congratulations on find the fix.

This is something to remember when it comes to electricity. It does not know the color of the wire.