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BPoland · 08-19-2019, 05:19 AM

I keyed this long post, and when I hit submit, it went into cyberspace. So here is the short version. Chassis battery keeps going dead, even after being plugged in for 5 days, and I can see the charge going to the battery. Thought it was a bad battery, but the battery seems to hold a charge. I put a meter on the battery, looking for an amp draw, and I'm showing 14 - 15 amps. Wow! That will kill it quickly. The house batteries seem unaffected.

Does anyone have any ideas on where to start looking. I know there is a fuse block on the side wall to the right of the emergency brake, and the power distribution box under the hood. I should be able to skip over any fuse less than 15 amps. But I cant think of anything that would normally draw that kind of current. Unfortunately, my days of crawling under a dash are gone, so I will probably have to pay somebody to find this.

Tanks for your thoughts.

nvs4602 · 08-19-2019, 05:36 AM

I would start pullin fuses one at a time until you found which circuit is causing the draw. How are you measuring the current draw. You said something about battery being bad have you tried it with a good new battery?

LETMGROW · 08-19-2019, 06:06 AM

Before you remove any fuses to do testing place your hand on the alternator to see if it feels warm to the touch. Do this with the engine off and cold.
If the alternator feels warm or hot disconnect the charge wire from the alternator and retest for an amperage draw.
Internal parts in alternators like diodes or rectifiers can short out and cause a current draw but still charge the battery albeit usually at a reduced charging rate.
If the alternator checks out OK then start removing fuses one at a time making sure everything run by the chassis battery is turned off.
Do you have a chassis battery disconnect? If you do, have you turned the disconnect switch to off and checked for current draw?
Another thing I'd try would be disconnecting the wiring to the power steps if they run off the chassis battery. Touching the step motor might reveal the motor is still drawing current even though the steps are not moving. On your unit I'm not sure if the power steps are powered by the chassis battery or the house batteries
if you have a chassis wiring diagram it might be helpful.
Lynn

BPoland · 08-19-2019, 06:07 AM

Quote:

Originally Posted by nvs4602

I would start pullin fuses one at a time until you found which circuit is causing the draw. How are you measuring the current draw. You said something about battery being bad have you tried it with a good new battery?

I originally thought that the battery just wouldn't hold a charge. That's why I pulled it out. I wanted to see if it would hold a charge. It started at 12.72 volts and two hours later, still had 12.72 volts.

As for testing the amp draw. I installed the battery and then removed the (-) cable. I set my meter up for Amps and put my meter between the (-) battery terminal and the (-) cable. I got a reading between 14.6 and 15.2 amps. Because it goes over 15 amps, I'm thinking it has to be a fused line of 20 amps or more, because I think were it a 15 or lower, it would have popped the fuse.

"007" · 08-19-2019, 10:01 PM

This has been found by some people with older coach's the alternator would not charge the chassis battery, the links are in this large one given to you, the answer came from this 12v link within in it..