Onan not generating power-gctid820368

[Guest]

Hello all, just wondering if anyone out there might be able to help me out. Last week while underway I started the Onan generator in our 1989 3888. It ran for a few minutes putting out power and then I realized that the air conditioning stopped working, but the generator was still running and the gauge on the dash was reading 12 volts. When we pulled into port I had a guy come look, and he told me that the generator itself was only producing 16 volts right out of the stator. I proceeded to the next marina and a technician tried to trouble shoot it but was unsuccessful as he could not find a service manual for the 29 year old Onan. He narrowed the problem down to possibly a bad transformer, but said when they go bad it looks burnt and my transformer does not look burnt.

I'm wondering if anybody else has had a problem like this. The Technician said not to throw bad money at bad money as the gen set was already 30 years old and really hard to find parts for. And then if you do it may only be a temporary fix. What bugs me is that its a fresh water boat with a clean bilge and only 300 hours on the genny.

Any help would be great!

[carguy]

Sounds like you have a couple people that don't know what they are doing. Here's a link to a pretty exhaustive manual: http://michaelstractors.com/forum/up...e%20Manual.pdf

I'd probably have someone look at it that knows what they are doing. It runs and it's putting out voltage. I wouldn't junk it just yeat. Finally, it's helpful if you put some info about your boat in your sig (year make model engines etc). It gives us a little more to go on.

[Pcpete]

I agree with carguy. Half of these guys, imo, only want to sell and install new units. I have the MDKD manuals, however, they are on the boat and I'm recovering from spinal surgery. It's going to be at least a month before the Admiral will let me near the boat and I'm not sure which of three lockers they are in. Most of the data from other models will apply with some adjustments.

I was warned early that having the Onan guys work on it is really expensive and I've found that asking about part numbers requires a serial number....even if I have the part number from the manual, they won't start looking at outdated numbers to see about selling me the latest version of that old part number.

I'd be happy to help in any way I can from a remote location. I've been able to get most of what I've need figured out, but mine needs some serious rust removal this winter.

[Yendrabuilt]

Manuals are online, and the Onan manuals have very good trouble shooting procedures. The circuit board controls the generator output and the engine run circuit.

[Guest]

Thanks Guys, I will grab some more info today.

[Guest]

Here's some pics guys!


Attached files

[Pcpete]

I hope to get mine as clean and good looking as yours! That's the same MDKD that I have. It's (duh!), the marine version of the DKD that is used in RV's and other land based applications, so some parts interpolation related to marine only is required. As to the power generation and management, they are so close it doesn't matter.

http://truckroadservice.com/barth_at...ice_Manual.pdf

It can be hard to find a repair mechanic in an environment where assembly replacement is faster, ensures a more predictable outcome and more profitable. I agree that there is a risk/reward/cost equation and, looks can be conceiving, but, imo, if you find the right tech and take your time, there will be a good result. I suggest looking into some of the rv and standby power generation shops as a source.

[Guest]

Just an update for the guys that replied. I had an electrician come out and look at it. Turns out it was a bad rectifier. $15 part! Thanks for all your replies.

[Pcpete]

So much for the "replace it becaits old" guys. Thanks for the update.