Car Battery Dead - car dealer says it is MH issue

[Mbylone]

Has anyone encountered a situation where the car battery looses its charge and they say it has something from the MH drawing power from it? After a few days of sitting, I have to charge the battery to start the vehicle. I was told by the dealer to take it to a Chevy shop to address. At the Chevy shop, they tell me it is because of some draw on the battery from the MH. We always leave the MH with the plug inserted into the outlet. When they take it out, they say the draw stops on the car battery. The dealer says this is impossible as there is not connection from the MH batteries to the car battery. NO one wants to fix it. Any suggestions?

[bowalker]

Several times the tow car battery was drained after 4 hours plugged up to the motor home while traveling. We discovered we sometimes leave something in the car on. Every time we make sure we turn every thing off, the battery stays charged.

[Bumpyroad]

I plugged my brake buddy into a small jumper/starter battery jobby to avoid drawing down the toad battery.
bumpy

[Golden_HVAC]

Hi,

It might be the braking system. What type of braking system do you have?

Many have found that the braking system was drawing power from the car battery, and have installed a +12 volt wire from the RV to the car battery to charge it while towing.

Good luck,

Fred.

[YC_1]

Very simple to diagnose but most mechanics just do not understand the electrical systems.

You really need an ammeter inserted into either lead of the car battery with the lead disconnected. A clamp on meter will not be sufficient unless there is a heavy flow. You may be looking for a 1/2 amp or less draw.

Answer downtheavenue's questions first though.

Working on vehicle electrical systems for 40 years I never say never to strange problems. All things are possible. I would like to know if you have a braking system on the car and if so what kind.

IF any of the folks looking at the problem used a statement such as (it has a 12 volt draw), move on. They have no clue what they are looking for. IF they cannot tell you how much current is being drawn they do not have a clue.

IF you want to chase it yourself, watch several you tube videos on how to measure current and then buy a meter.

With the vehicle unattached disconnect the negative or positive cable of the battery and measure the current. The connect the pigtail and measure again. If you see any increase in current you have an issue. If not, connect the battery again and start the mh. Measure the Voltage across the battery. You should see 13.5 or so. If 12.7 or less then the rv is not charging the battery. Start the car and you should see the same higher voltage.

[DownTheAvenue]

Mbylone wrote:
Has anyone encountered a situation where the car battery looses its charge and they say it has something from the MH drawing power from it? After a few days of sitting, I have to charge the battery to start the vehicle. I was told by the dealer to take it to a Chevy shop to address. At the Chevy shop, they tell me it is because of some draw on the battery from the MH. We always leave the MH with the plug inserted into the outlet. When they take it out, they say the draw stops on the car battery. The dealer says this is impossible as there is not connection from the MH batteries to the car battery. NO one wants to fix it. Any suggestions?

Does the Chevy battery go dead after a few days of sitting if not plugged into the motorhome?

If yes, then it is definitely a Chevy problem.

If no, then it is definitely a problem with the motorhome connection.

[midnightsadie]

well we all know you have a problem, and two dealers don,t want to help you. I,d find a dealer who does nothing but trailers tell them whats happening, might have to re wire ,here in ohio I know two dealers that would fix it. you need a dealer that wants to help you.

[GrumpyandGrandm]

It depends on how your toad was wired up and what type brake system you are using. Our MH is wired to charge the car while driving since I use a Brake Buddy system. I do find it very hard to believe however that your car battery would go dead in that case since the MH batteries would have to deplete as well. We've sat connected for several days and have never had the toad battery go down. .

[Bumpyroad]

Mbylone wrote:
Any suggestions?

yes, unplug toad from MH when sitting.
bumpy