Batteries won't hold charge - need help

[sgordon_lazydaz]

Hi All,

Newbie here so please excuse any ignorance. I have a 1992 class c Lazy Daze with a Chevrolet G30 cab.

I purchase her in March and drove every week/weekend with no problems for about 3-4 months. Went to go move her one day and both car battery and house battery were completely dead. Discovered I had left a small fan on for two days (oops) so it made sense. I replaced both batteries and made sure nothing else had been left on. Drove around for a couple days, then- bam - wouldn't start again. Both batteries dead- this time nothing was left on and nothing was draining power. Had a mechanic come out and alternator was reading as dead so I had the alternator replaced and once again replaced both batteries- started up no problem. Next day I drove her for about 3 hours, still no problems. Day after that, both batteries dead again. After doing some research I discovered the purpose of the isolator. So, my question to you all is- do we think if I replace the isolator (seems easy enough to replace myself) that this will solve the problem? Or do we think it's necessary to have it towed to an RV mechanic? I'm in a bit of a tight spot as I'm in the process of moving into her full time and leaving a failing relationship so will take any help I can get to have this fixed asap.

I've gone ahead and ordered a new isolator (same as the current one installed - diode) that will arrive tomorrow. I will try and replace my car battery though Autozone warranty for the 4th?? time but not sure if they will give me another within the warranty.

Please help!

[Matt_Colie]

SGordon,

Until you get it sorted out, get in the habit of pulling the negative cable of both the chassis and house batteries when you shut down. It will be a pain I know, but it is easier that dealing with dead batteries all the time.

Now, as soon as you can, get wire, two alligator clips and a small 12V bulb. Solder the wires on the bulb and the clips as well. Then put it between the disconnected battery cable and the battery. If/when it lights, you have a problem (I think you know that), so, keep pulling fused and disconnecting things until the light goes out.

You bought this coach used. There is a real good chance that someone that doesn't know better hooked things directly to the one or the other of the batteries. This happens all the time.

Matt

[SJ-Chris]

If you need a quick solution (which your post states), you can consider adding one of these to each battery and disconnecting them each time when you leave them. Simple to install. That will guarantee nothing is being drawn from the batteries while you are away. That will give you time to fix the problem later once you get settled in.

https://www.amazon.com/gp/product/B07SBFKM5Y/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Good luck!
Chris

[bobndot]

While looking at the amp draw on your meter, start pulling the coach rv fuses one at a time until the meter shows which circuit the problem is on. At least that will narrow things down .

On the truck side : Having a 50mA draw on the chassis battery is normal. That low draw will take a long time to deplete a good battery.

While checking amp draw make sure you put tape over the door switch to keep the interior light off.

[sgordon_lazydaz]

Water pump, water heater both have been switched off. I installed an inverter to the house battery but it's off when I'm not using it. Rear camera wired directly to the house so could be actively pulling power? But then again I had installed for months with no battery issues. Will obsessively search again for any compartment lights. Wouldn't a fuse appear blown in house if there was a short? Ive checked the house fuse box and all fuses are good. How about fuses related to car battery? Any idea where those would be located?

By bad ground do you mean the actual connection to the ground on the battery? Sorry I have very basic electrical knowledge and very little knowledge of cars. This is proving to be a good excuse to educate myself more on both.

The isolator seems to be connected to both batteries but unsure exactly how it's wired.

I'll check for a built in CO detector, I installed a smoke/co detector in the ceiling but it runs on batteries/not wired to house.

Any other tips are highly appreciated! So glad I found this community.

Thanks!!

[capacitor]

CO detector? Do you have a battery isolator for the coach batteries?

[Diamond_c]

I hate electrical problems! I’d start looking at water pumps and the like, or maybe a bad ground. After that I’d have to find a better mechanic. For sure there’s something drawing power that shouldn’t be.

[bgum]

Tank heaters or short somewhere or light in one of your storage compartments.

[sgordon_lazydaz]

Thanks so much for the reply, Gary. Any idea what could be on? Something that may not be obvious like a fan or light- I'm not sure what to look for. Yes, I have access to a multimeter to check voltage. Voltage on car battery is reading under 12v. Since I cant start the engine due to dead battery, I'm not able to read voltage coming from current isolator. I imagine I need to replace the battery in order to move forward with trouble shooting?

Thanks again!

[Gary45]

It's easy to replace the isolator, if the both batteries are dead that quick something is drawing power all the time. Check and make sure nothing is on. Do you have a volt meter? If you do you can measure how many amps are being drawn from each battery, leave wires disconnected and isolated at the isolator so you can check each battery separately. You have something on, likely on the house side.

[Lwiddis]

Read the warranty closely and take them back if there are no specific exclusions. Not what they say…it’s what they wrote.