Generator Keeps Blowing Fuse

[Cabreco]

This is obviously a short somewhere I just want to see is someone here can point me to a good starting place.

My 94 Dutchman has an Onan Marquis 5000. Works great. Last year I would occasionally blow a small fuse at start up. Not knowing at the time why the generator would crank & not start I thought it was a clogged fuel filter. It turns out that fuse is for the fuel pump.

Now the fuse blows on cranking IMMEDIATELY.

Any suggestions on where to start tracing?

[16ACE27]

Sounds like a bad fuel pump to me. The problem has to be downstream of the fuse which should be a very short wire run to the fuel pump. Any problem upstream of the fuse will not blow the fuse.

[Cabreco]

Originally Posted by 16ACE27

Sounds like a bad fuel pump to me. The problem has to be downstream of the fuse which should be a very short wire run to the fuel pump. Any problem upstream of the fuse will not blow the fuse.

Well now I have a starting point!

Appreciate the assist!

[Cabreco]

Originally Posted by 16ACE27

Sounds like a bad fuel pump to me. The problem has to be downstream of the fuse which should be a very short wire run to the fuel pump. Any problem upstream of the fuse will not blow the fuse.

I think you may be right. That F2 fuse that blows is for the fuel pump & solenoid as well as the auto choke.

Here's what I've done.
1. I disconnected the auto choke - BLEW FUSE! then reconnected
2. I disconnected the positive Terminal of pump - DID NOT BLOW FUSE
3. I disconnected the other side of the fuse and did an OHM test between where the fuse connects to the power source & to the positive wire of the pump. - GOOD CONTINUITY, NO SHORT
4. I did an Ohm test across the pump terminals and the multi meter showed 1 before touching both terminals 0 when I touched both


Ok so If I have read this correctly I need to replace the pump. Can anyone confirm this?

Thanks

[16ACE27]

Still sounds like a fuel pump to me. Seems like there should be some resistance reading across the fuel pump terminals, not 0 ohms.

[Cabreco]

Originally Posted by 16ACE27

Still sounds like a fuel pump to me. Seems like there should be some resistance reading across the fuel pump terminals, not 0 ohms.

I tend to agree

[Cabreco]

Looks like the pump is the culprit.

I just got in the new one. I disconnected the power leads on the bad one and attached them to the new pump while holding it in my hand & cranked the generator.
Fuse did not blow.
I'm replacing it tomorrow.
BTW would anyone know what amp that fuse should be? It currently has a 30amp in it but I think that is over the top

[Trkyte@msn.com]

30 amp sounds ok to me. Remember the choke is a heating e
Element, fuel pump is a electrical magnet and a solenoid is also.