Auxiliary start issue

[MrTools]

2002 Holiday Rambler Endeavor 36PBD. Won't start anymore unless I use 'auxiliary start'. If I turn the key, as I've always done before, it just clicks. Chassis battery voltage is 12.8, so that's ok. To start it now I need to turn the key, then push the 'auxiliary start' button. Any ideas? Perhaps a relay of some sort has gone bad? Thanks, in advance for any advice.

[8.3Oilbuner]

Hi MrTools; You can have a proper battery voltage but the battery has no capacity, the amount of amps needed, to provide enough amperage to turn over the engine. By connecting to your house batteries you are now getting enough amps to do the job. You need to have the battery or batteries tested for load. Before removing the battery, or batteries in the starting end of the business I would try charging your chassis battery for at least 24 hours. I then , with a hydrometer check the electrolyte level in the battery and see if it shows that it is fully charged. If you have sealed batteries you will need to take them in to be tested. That is the route I would take.

I keep my coach plugged in 24/7 and my Windsor charges both house and chassis batteries. On an Endeavor I am sure the invertor just charges the house batteries when plugged into shore power. I check the electrolyte in both sets of batteries every other month so I know their health.

[Ivylog]

Turn your headlights on and try starting the normal way with someone watching the headlights... bet they go out. Engine batteries going bad or bad connections,

[Timaz]

Cheap stuff first. Take your cables off of the start battery and make sure they are clean. If clean follow what has been said.

Tim

[tinstar 1114]

I was fooled once by reading battery voltage of 13.6 BUT it wouldn't even begin to turn the engine over. Like 8.3Oilbuner said, you don't have the amperage needed to do the job. One or more dead cells.

[YC1]

Put the voltmeter across the battery terminals and then have someone turn the switch.

Surface voltage means nothing. You can have water in a hose but with no pressure on the end nothing comes out.