Onan 4000 Generator won't turn over some of the time

Kinda late but i want to share my experience. I bought a used '99 Tioga a few months ago. 900 hrs on the genset. When inspecting it, the seller had a tough time getting it started but after a few tries it started and ran good. It continued to be a pain to start. It would spin once, then nothing. Spin once, then nothing. It acted like a dead battery but they were ok. After a few tries it would start. Then before leaving for a trip i wanted to pre flight it. It almost started then NOTHING. nothing at the remote and nothing at the genset. Breaker and fuse ok. 13.6v at both sides of solenoid. ARG! Starter! Searched the net for instructions how to change the starter. No luck. So, being inclined i decided to attack it alone. Contacted Anyrvparts nearby and they verified the correct starter for about $100. Started arrived the next day. I disconnected the batteries for both vehicle and coach. Removed battery cable from solenoid and gas line (plugged gas line with clamp and bolt). Removed the 4 bolts securing the unit to the frame. I built a 2x4 frame to slide the genset onto. That way i could slide the genset out at an angle without removing the wire harness and it was enough room to remove the genset cover. Removed the cover and the starter is located at the top left rear. Easy to get to. I found the problem. The nut holding the battery cable onto the starter was laying at the bottom of the genset and the cable was disconnected from the starter. I could see that the cable had been arcing (the one spin, no start issue) before it fell off. Changed the starter, put it all back together and it started the way it is supposed to. Very easy to change it yourself.

Thanks all. I'll check the voltage at the solenoid and if that's not it I think I'll take in to the shop.

I appreciate everyone's comments and expertise, this has been a very helpful discussion. I'll post the final outcome when the results are in.

I disconnected the exhust and pulled the genny out , not a real fun job but the only way. No way to repair/remove installed.

dclarke618 wrote:
The Gen is in a tight spot and I can't get the screws out on the right side to remove the cover. Looks like it will have to come out. I cleaned the solenoid connections last night and it would not turn over after that. I finally grabbed the wires and shook them around and it has been working fine ever since. The problem is that I can't see any wires from the solenoid to the starter without taking the cover off. It looks like a loose connection at the starter and I need to figure out a way to get to it, preferably without taking the whole gen set out.

It's been awhile since I've been in a gen like yours.
On the solenoid red for hot from battery to your soleniod and the wire on the the other post of the solenoid I believe that wire was white and it goes over the top of the gen staight to the starter. When the start button is pushed the solenoid sends 12 v to the starter so when you let off the start switch its kills power to the starter.
That's where I'm talking about using the multimeter on the solenoid post to the starter to see if your getting 12 v with the start switch engaged . Might save you pulling the gen. Sounds like its in your solenoid.

The Gen is in a tight spot and I can't get the screws out on the right side to remove the cover. Looks like it will have to come out. I cleaned the solenoid connections last night and it would not turn over after that. I finally grabbed the wires and shook them around and it has been working fine ever since. The problem is that I can't see any wires from the solenoid to the starter without taking the cover off. It looks like a loose connection at the starter and I need to figure out a way to get to it, preferably without taking the whole gen set out.

dclarke618 wrote:
For a 1998 Winnebago Adventurer do you have to drop the generator in order to remove the main cover and replace the starter?

I don't know your trailer but you have to take the cover off. If its in a pretty tight compartment you will have to take the gen out to get to the starter.
How much room is there on the sides that's where the torx head screws are that hold the cover on two on each side. Then you would have to have room at the top of compartment to get the cover high enough to get it off .
Do you have a multimeter and know to use it a little bit ?

For a 1998 Winnebago Adventurer do you have to drop the generator in order to remove the main cover and replace the starter?

dclarke618 wrote:
Bird Freak,

Did you replace the starter and if so how difficult was it or what did it cost?

It wasn't very difficult to take out and I had my local starter shop rebuild it for me. he is the same shop I use through my restoration shop and he did not charge me so I have no idea about cost.

dclarke618 wrote:
Thanks Aruba5er,

How difficult was it to get the starter off and back on?

The starter is not that hard to get off its just getting to the starter.
Depends on the housing you have 4 torx head screws to pull the shell off the gen then reach to the back of gen two bolts holding the starter on and wires. Possible for it to be the connections at the starter or the start solenoid.

KSG,
I have not tried that. I did add a 3rd battery recently and all 3 have been fully charged.

Thanks