Electrical problems galore

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Jan 8, 2009
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Texas
I have a 2012 Chevy Express 4500 motorhome with 55,000 miles. First and last GM vehicle I'll ever own. In the last three years it hasn't started because: defective fuse box (too much voltage drop), bad fuel pump, bad starter, battery lasted 14 months and now bad crank relay.

Is there something causing all these electrical failures, or is it because it sits a lot or is it just typical GM?
 
Are you starting it just to start it? The better way is to get the engine up to operating temp for 15-20 minutes every time you start it. Preferably by driving it. Battery maintainer if its going to be months between starting it.
 
Are you starting it just to start it? The better way is to get the engine up to operating temp for 15-20 minutes every time you start it. Preferably by driving it. Battery maintainer if its going to be months between starting it.

It sits in a storage lot under a tarp, so if I understand correctly a battery maintainer is not an option. I go start it once a month, get it up to operating temperature and put it in gear. Not thrilled at the idea of hauling the battery back and forth.

As far as bad ground, Costco said the battery died due to a parasitic loss. How ever the only draw I saw was 0.6 amps for 30 seconds after which it consistently drops to almost nothing (0-0.1 amp). Donald are you suggesting that a bad ground is frying all or most of these electrical components?
 
Is it possible to use a solar battery tender and somehow affix the solar panel on top of the tarp?

I've been using one of these for a while on a seldom used truck and so far it's working great!
 
.1 amps is too much. You need 30-35 milliamps or less when all the modules are asleep. I suggest disconnecting the battery cables and removing the battery when not in use.

The fuse boxes are unfortunately somewhat common for that issue. Fuel pump failures are common on GM vehicles across the board, especially trucks. Most of those failures are not out of the ordinary for that vehicle.

It would not be a bad idea to check all battery and chassis grounds to make sure they are clean.
 
I have heard of GM having faulty fuse boxes. My 2010 Traverse was riddled with electrical problems; faulty window switches, faulty power mirror switch, odometer display failed, radio speakers failed, and there were the random, unexplained "Service Stabilitrak" messages that popped up occasionally. It was actually making the Lucas stuff in my MG look pretty reliable.

I agree, 100mA does seem a bit excessive for parasitic loads. Maybe invest in a quick disconnect at the battery?
 
It sits in a storage lot under a tarp, so if I understand correctly a battery maintainer is not an option. I go start it once a month, get it up to operating temperature and put it in gear. Not thrilled at the idea of hauling the battery back and forth.

As far as bad ground, Costco said the battery died due to a parasitic loss. How ever the only draw I saw was 0.6 amps for 30 seconds after which it consistently drops to almost nothing (0-0.1 amp). Donald are you suggesting that a bad ground is frying all or most of these electrical components?
I would not blame GM for these problems because the upfitter who used the chassis is 99% of the time responsible for all sorts of troubles as they build the RV. Think of all the modifications and additions they do to make it an RV. Lastly - any battery is going to lose a small amount of charge over time and vehicle computers, radios, clocks etc will draw additional power. You have to maintain the battery - period. Starting a vehicle and running it even 20 minutes will NOT keep that battery charged at 100%.
 
6,900 miles a year average isn't bad for a motorhome for keeping it exercised, have you been putting about that on it the past 3 years?

In the storage lot where we keep our trailer some people have solar panels sitting behind their RV to maintain their battery.

When you have an RV you have 2 hobbies, the traveling and the working on the RV.:oops:
 
6,900 miles a year average isn't bad for a motorhome for keeping it exercised, have you been putting about that on it the past 3 years?

In the storage lot where we keep our trailer some people have solar panels sitting behind their RV to maintain their battery.

When you have an RV you have 2 hobbies, the traveling and the working on the RV.:oops:

I should have said it drops to 0-0.01 amps. Barely measurable on the 5a setting. I should've but didn't switch it to the lower range on the meter.

The original owner drove it from Texas to Alaska and back. We were doing about 6,500 miles a year except the last couple years.

I don't mind tinkering maintenance, but when you're out on the road and it only starts 9 out of 10 times, you find yourself blocking the entrance to a national park and the shop can't get to it for a week or two, that's not good.

The solar panel sounds like something I should look at although it seems like there'd be a high likelihood of theft.
 
This is what I recommend for RV or cars in storage. 15 9n Amazon.
 

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Sounds like a bad ground somewhere. You can’t really blame GM for this though. Upfitter vehicles often times have very questionable work done to them.
 
I repair a lot of Fuel Pump primary circuits on GM trucks & vans, I bypass the underhood fuse box altogether, Run 12 gauge wiring & a heavy duty 50A Bosch Relay & a 20A Maxi Fuse. 12 is the max gauge for the GT150 connector at the Fuel Pump/Sender.

Your other issues aren't all that common to this chassis, Tarping the vehicle in high humidity is just asking for corrosion related electrical issues & Low Battery voltage is compounding it!

There are thousands upon thousands of tradesmen that use this chassis everyday for their livelihood & swear by them NOT at them ;)
 
I use a 100 watt solar panel from Costco on my trailer. I lock it to the trailer tongue with a chain and padlock.
 
I repair a lot of Fuel Pump primary circuits on GM trucks & vans, I bypass the underhood fuse box altogether, Run 12 gauge wiring & a heavy duty 50A Bosch Relay & a 20A Maxi Fuse. 12 is the max gauge for the GT150 connector at the Fuel Pump/Sender.

Your other issues aren't all that common to this chassis, Tarping the vehicle in high humidity is just asking for corrosion related electrical issues & Low Battery voltage is compounding it!

There are thousands upon thousands of tradesmen that use this chassis everyday for their livelihood & swear by them NOT at them ;)

It's a quandary because if I don't tarp the outside weathers something terrible. I don't see evidence of corrosion elsewhere, but good feedback. Thanks.
 
Get an intelligent charger and charge it at least once a month, better yet, once a week. Disconnect it when not charging.

See if you can suspend the tarp over the vehicle instead of putting it directly against it, more like a canopy than a tent, not fully contained. Allow for airflow in all directions.
 
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