Replacing a Onan 4.0, same model, How hard is it?

[map40]

I got it off the internet, I can handle the weight, and my generator is mounter on sliders. How difficult is to remove the old and install the new one?

[shastagary]

take pictures of the installed generator and any connections as you disconnect them then there will be no questions if it was connected correctly.
use your cell phone or a camera to take the pictures as you go.

[maillemaker]

Depends on your RV. On my 1990 Winnebago, it's pretty easy. I bought a $10 rolling dolly from Harbor Freight, and stacked 4x4 pieces on top of it like a log cabin until I was close to the height of the generator belly pan. Then I used a hydraulic jack to lift the outboard side of the genset so that I could remove the brackets there, then I lowered it until it rested on the 4X4s. Then I moved the jack to the inside side of the genset, and jacked it up lightly. I removed the "keepers" on the two hinges, then jacked the genset up slightly until it came off the hinges. Lowered the genset back onto the 4X4s, and then rolled the genset out of the compartment.

Before I did any of that I disconnected the battery and fuel.

There is enough service loop for the 120 VAC output that after I rolled the genset out of the compartment I could disconnect it. It terminated in a junction box under one of the kitchen table bench seats. I undid the electrical connections from the seat box, then went back underneath and disconnected the armored cable termination. Then the genset was free to be taken to the shop.

Steve

[DrewE]

Chris Bryant wrote:

DrewE wrote:
It should be fairly straightforward, though it may take a bit of time and effort. The fuel and AC power connections require removing the starter solenoid, voltage regulator, control module, and the switch/fuse/circuit breaker panel piece in the generator (all of which can be done through the usual access panel on the generator).

What? I've never had to do that- the set comes with the 120 volt leads in place, the fuel connection is external and the battery connections are right up front- ground on the outside, positive is the starting solenoid.

Maybe they've changed it since mine was built, or maybe I was just dealing with a less than helpful original installation, but I think that's what I had to do to drop mine. The DC connections were as you described. I think the fuel connection was inside the generator, though I could be remembering that part incorrectly. I know I pulled the 120V connections from inside the generator. It could be that they were going through an Onan-supplied flex and I just couldn't get at the other end very easily in my particular installation; I didn't study it to see whose flex 120V connection it originally was.

Regardless, it's not problematic in any case.

[Chris_Bryant]

DrewE wrote:
It should be fairly straightforward, though it may take a bit of time and effort. The fuel and AC power connections require removing the starter solenoid, voltage regulator, control module, and the switch/fuse/circuit breaker panel piece in the generator (all of which can be done through the usual access panel on the generator).

What? I've never had to do that- the set comes with the 120 volt leads in place, the fuel connection is external and the battery connections are right up front- ground on the outside, positive is the starting solenoid.

[DrewE]

It should be fairly straightforward, though it may take a bit of time and effort. The fuel and AC power connections require removing the starter solenoid, voltage regulator, control module, and the switch/fuse/circuit breaker panel piece in the generator (all of which can be done through the usual access panel on the generator).

[Chris_Bryant]

Not hard. Reuse the flex conduit on the original, 120 volt wiring, 12 volt wiring, control is a plug, fuel line, exhaust. That's pretty much it.