MEP 803A shorted battery

[Louis9113]

Hi,
I’ve searched SS but can’t find the answer. My dad was disconnecting the batteries and the loose terminal flopped and shorted, causing a large spark. He said the relay behind the instrument panel keeps tripping when attempting to start. He installed a new one and same thing. Any pointers as to what got fried when the battery cable shorted? Thanks!

 

[Guyfang]

What relay? If you dont know what it is and for, take a picture.

 

[Louis9113]

When you turn S6 to prime, CB1 pops out.

 

[Light in the Dark]

Well when you are at prime and run, you are powering the fuel pump... unplug that and see if the breaker pops.

 

[Guyfang]

When you turn S6 to prime, CB1 pops out.

You mean S1, the Start switch? Have you downloaded the TM's for this set? A quick reading of the operators TM will help you find your way around the gen set easier. Click on the link below.

MEP-803A, All the TM's you need

 

[Louis9113]

I’ll plow through the TM’s over the weekend, thanks!

 

[Daybreak]

Howdy,
Start here in this thread.
Generator Forum Stickies.

MEP-802A MEP-803A Filters and Parts

The second post has quick links
The third has the manuals needed, and links

 

[Louis9113]

Well when you are at prime and run, you are powering the fuel pump... unplug that and see if the breaker pops.

He unplugged the fuel pump and it still tripped. Dead crank will turn it over.

 

[nextalcupfan]

The only things I can think of that get energized in RUN/PRIME are the Fuel Shutoff solenoid and Alternator trigger wire.
but the Fuel Shutoff should be through a relay.
Personally I think I would take all the ice cube relays out and see if it still trips, while looking for potential wire rub outs.
These sets vibrate enough that its actually pretty common.

Personally I found a spot behind the main control panel that was starting to rub out.

 

[Guyfang]

Help?

 

[Louis9113]

Funny how symptoms and problems collide. My dad had disconnected the batteries (sparked cable in process), cleaned the terminals on the fuel gauge (primary reason for disconnecting the batteries), and just called to say that after 2 hours, he found that he had hooked the wires up incorrectly back on the fuel gauge. He called and I could hear it running in the background

 

[Guyfang]

You will never know how often this kind of thing happens. When ever I unhook something, I never mark wire with tape or other such nonsense. I look at the schematic. Its there on your set. So why not use it? Always check twice if not three times the wires. Know, instead of think. Be glad it was a simple fix!!

 

[Louis9113]

I know guyfang will appreciate this

 

[Guyfang]

GOOD MAN!