Jump to content

7500 Onan will not start


Recommended Posts

I'm about to go on a 4-hour errand, so I wanted to post this before leaving.  I'll return this afternoon.  I'm planning to leave on a trip tomorrow morning.

I have a 35 code, which simply says "Needs Service".  Pressing the Start button from any of three locations does nothing.  No click.  No engine turn over.  The lights---blink-blink-blink  PAUSE  blink-blink-blink-blink-blink, which I'm interpreting as Code 35.

I'll work on it some more when I get back today.

Van Williams  2000 Dynasty 36   ISC-350  Onan   7500 Quiet Diesel (inverter-type)

Link to comment
Share on other sites

There are 3 fuses under the small access panel above the start button on the generator.  I'd start checking those 3 fuses, I know one of them has to do with the starting function.  I believe one is a 25 amp fuse and the others 10 or 15 amp. 

Link to comment
Share on other sites

Thanks, Jim.  I only saw two fuses under that cover.   I'll look again.  Both fuses good.  Oil and coolant were OK. Disconnected/reconnected the multi-pin line going to the genny.

Link to comment
Share on other sites

On mine two of the fuses were attached to the neck of the coolant fill, the other was loose.  

When my wife was trying to get her's going late last month she found the loose one but the others were attached to the neck and at first glance didn't see them while we were doing a Facetime call. 

Edited by jacwjames
Link to comment
Share on other sites

17 minutes ago, Ivan K said:

I hate to even mention it but isn't  code 35 for self check failure on the control board? Maybe try reseting the connector? Wish it's something easier and cheaper than that.

Would explain it not even attempting to start!

Link to comment
Share on other sites

31 minutes ago, Dr4Film said:

@Ivan K is correct.

C&P from the 7.5K Manual -

CONTROL CARD FAILURE FAULT—CODE NO. 35
(Microprocessor EEPROM error during self-test)
Corrective Action: See an authorized Onan dealer.

Ain’t but one call needed.  FlightSystems.com.  They are the experts on boards and board repairs and also refurbished replacements.  They do, as of a member’s recent post, allow returns if issues other than the main board…. They also provide tech support to diagnose.  Onan is good….these guys are better

Link to comment
Share on other sites

10 hours ago, 96 EVO said:

Well, hopefully you are traveling shore power to shore power.

Thanks!  No other choice.

Link to comment
Share on other sites

  • 2 weeks later...

I'm home from my trip.  I'll tear into the genny soon.  I never did find the third fuse.  Anyone give me any more directions to find it?

Also, assuming the 35 error code is correct, I must remove the front section of the genny, containing the electronics.  Anyone done this?  I'm sure I'll figure it out, but anyone's experience would be welcome.  Looks like I have to slide the genny back a few inches to get the room, but there are only four bolts holding it to the slide.

I'll also have to build a lightweight, but bulletproof, wooden box to ship it to Flight Systems and back.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...