txnese wrote:
The chassis engine fires right up, so that battery is good. I checked the house batteries with a volt meter and it reads about 12.6 volts. I also checked the generator's starter relay, got 12 volts on input side, and 0 on the output side. I push to start the generator and the output side shows like 4 volts. I was thinking bad starter solenoid, so I used a starter jumper switch to give the output side 12 volts and nothing still happens. I would replace the starter itself, but the light on the button is dim. I almost want to blame the control board, but don't know enough to condemn it. I'll do some checking in the morning. Just doing what I can before I turn it over to an RV shop.
The control board would not affect the voltage drop when the solenoid is engaged; the current for the starter does not go through the control board, but just from the battery positive (on one side of the solenoid), through the solenoid to the starter, and then to ground.
You have either a poor connection somewhere or a bad battery. Note that the generator often starts from the house battery, not the chassis battery, so the fact that the motorhome engine starts right up does not mean the battery supplying the generator is fully charged.
Assuming the house battery is charged, I would go over the wires to the battery, both the positive and ground ones, and the positive and ground connections at the generator. Something is almost certainly amiss there somewhere. The generator starter is a significant load (albeit of short duration), somewhere around 100A or so, and it doesn't take much of a poor connection to cause a significant voltage drop that would not be particularly noticeable for many other devices like lights etc.
I've seen a few battery cables that were corroded near the connectors inside the insulation, such that at first glance they looked okay when in actuality they were nearly or entirely open and just about falling apart.
