Welcome to the Hatteras Owners Forum & Gallery. Sign Up or Login

Enter partial or full part description to search the Hatteras/Cabo parts catalog (for example: breaker or gauge)
+ Reply to Thread
Results 1 to 4 of 4
  1. #1

    Trouble shooting 8k MDKD GEN with only 30v output

    Seeing if anyone has good source to ask some questions on transformer regulator style genThanks

  2. #2

    Re: Trouble shooting 8k MDKD GEN with only 30v output

    Mike Peters, 1985 43MY, Cat 3208T, Blue Bayou; 2011 Key West 246BR, F250, Baby Blue; Punta Gorda FL

  3. #3

    Re: Trouble shooting 8k MDKD GEN with only 30v output

    Hello, my MDJE 7.5 gave me this issue a few years ago and caused me to remove and install the set three times. It would work great in my garage but not when in the boat. I realize this sounds crazy but true. The things I did do were to clean the slip rings, changed the brushes and cleaned all of the wire connections on the magnciter. I also found a poorly installed fuel pickup that I replaced. So far this year I have been testing it and I think, hope I have won this war. Fuel is not your problem as it just happened to stop now, mine was not working after a two year layup. Search the net and find every onan manual that you can, I found an Onan servive manual which was very good and covered my model. There will be a procedure to check the magniciter. You will have to get the end bell off to find the terminals. Also take note of the model number on it to get the proper method and terminals to connect your meter to. A member here actually changed the diodes on his and it has been going strong ever since. Try searching Onan 7.5 MDJE to read his posts. I too tried Smoke Stack and got no help from anyone and was told I must have done something to it to have it stop working properly. You can search those posts also to see for yourself. I dont mind working at mine but if i required power when out cruising it would be gone and a northern lights plant in its space very quick, i just like the challenge.

    Good luck with it.
    Walt Hoover

  4. #4

    Re: Trouble shooting 8k MDKD GEN with only 30v output

    I have had the same problem twice on my MDJE 7.5. The first time it was an open circuit on the exciter stator that had corroded through. The second time was a failed diode on the rectifier. I replaced it with a modern potted rectifier from eBay. A brilliant piece of McGuyvering if I do say so myself! Hundreds of hours of trouble-free use since. Any competent generator tech (and that would not be me)should be able to do the same.
    If you decide that you want to DIY, fell free to contact me. If you have some skills and a multimeter it's fairly easy to diagnose.
    Greg Harrington
    43 DCFB 1977 w/Cummins 903 M1 (340HP)
    Hull #454

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts