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3DMYWAY · 08-20-2011, 08:40 AM

Diesel engine for the generator will not start so I'm debugging the problem. Have the above diesel gen unit and measure only 7.5 volts to the fuel pump which seems to be low. Manual states fuel system operates at 12 volts but design could be such that a lower voltage is applied to the fuel pump. I called Onan yesterday but have not had a callback on my problem.

Looked at the installation manual but I cannot find the fuel pump in the schematics so I cannot trace from the coach cable into the generator control box to the fuel pump

. Does not make sense...voltage should be 12 or 0!!!

Any ideas how to solve this problem other than taking to shop? Thanks for any help.

Chris

bigskymt · 08-20-2011, 09:36 AM

During cranking the voltage at the pump may be lower then 12vdc. Can you measure the voltage at the starter when you crank?
Try engaging the battery boost to raise the voltage.

3DMYWAY · 08-20-2011, 12:00 PM

I had already disconnected the starter then measured the voltage at the fuel pump connector disconnected from the fuel pump. For a moment

thought that would do it.
Still hopeful someone will have an answer on 12 volt source through the control panel.....but at a loss here....grasping at straws...any straw...

Big Oil Guy · 08-23-2011, 11:53 PM

Here ya go:

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

3DMYWAY · 08-24-2011, 03:42 AM

Ken,
Thanks, that does it. Will now locate K14 and measure the voltage. Appears it is straight through the contacts from B+ so there are no modifiers (regulators) to mess it up...should be straight battery voltage. Maybe some mice have been at work

. Replaced filter, and have all diesel pumped out of MH for cleaning....bet that effort was moot.
Again, thank you.