Onan Marquis 5500 won't start

[Edriscoll]

Tried to start generator, was acting like low house batteries ( turned over slow, no start). Next day I tried again after charging batteries, now just got clicking. Replaced house batteries, still just clicking. Checked voltage at main 12 volt cable on generator and it is 12.43 volts. The Bounder is a 99 model, generator has 900 hours. Noticed when trying to start from dash switch that interior lights dim badly, like there is a short somewhere. Anyone seen this before?
Thanks,
Ed Driscoll
99 34V - bought new in 99

[Randalpho]

Sounds like you have a voltage drop between the battery and the starter or ground, or the starter is bad. Check all battery cable connections, positive and grounds. Can you check the voltage on the starter cable at the gen while someone attempts to crank it?

I had an intermittent starter issue when I first got mine and it turned out the battery cable was loose on the starter terminal. I saw it arching while the DW attempted to crank it.

[rk911]

do you have a second or even a third switch sonewhere? we have three...one ON the genny, a second in the hallway near the master controls and the third on the dash. my point is...see if the problem is isolated to the dash SWITCH before anything more complicated.

[twinboat]

Check the end of the negetive battery cable that goes to the chassis. It needs to be clean and tight, along with every other connection. Wrench tight, not finger tight.

What kind of batteries did you remove and did you install new ones of the same type ?

[Edriscoll]

Voltage drops at generator to 5 volts on startup attempt, so connected 300 amp industrial strength charger in 300 amp start position directly to generator chassis and 12 volt input from battery. Still nothing but clicks.

[NXR]

Originally Posted by Edriscoll

Voltage drops at generator to 5 volts on startup attempt, so connected 300 amp industrial strength charger in 300 amp start position directly to generator chassis and 12 volt input from battery. Still nothing but clicks.

If the batteries are capable of providing the current needed to start the generator and still are dropping to 5 volts you either have a seized-up starter or a seized-up generator because you're essentially putting almost a dead short across the batteries, minus the voltage drop in the heavy cables.

• How old are the batteries?
  
  
• If the batteries were capable of providing the starting current needed for the generator, and the generator is not seized up, they would never drop to anywhere near 5 volts. My 5500 drops the voltage to about 11.8 volts while cranking.
  
  
• Without using the charger and measuring the voltage directly at the batteries, what does the voltage drop to when trying to start the generator?
  
  
• If it still drops to 5 volts, what does the battery voltage drop to when running a high-current DC device such as the propane furnace? If the voltage as measured directly on the batteries stills drops a lot, you have bad or discharged batteries.

Ray

[Randalpho]

Check your grounds like Twinboat suggested. You will have a ground cable from the battery to the frame and a ground cable back at the generator to the frame. The fact that your interior lights are dimming while cranking, and if your batteries are in fact good, tells me you have a poor ground between the battery and the chassis frame.

What's the voltage at the battery while cranking?

[clifford j]

The OP just stated he had his super charger right at the generator, connected to the generator chassis and the battery terminal at the generator, seems that would eliminate all the wiring back to the vehicle battery. AND the generator starter just 'clicks' when he has the charger on 300 amp boost.
Somebody suggested seized engine,, starter motor issue. Good place to start checking.

CLIFFORD

[Edriscoll]

Thanks. I am at the point of looking for a reliable Onan service shop because I agree it has to be starter related.