No power to the main fuel pump on MEP803a

[Chanderson69]

Hey, everyone. I recently purchased an MEP 803a with 320 hours. it’s in great shape and nothing seems out of place. However I’m not getting power to the main fuel pump through the master switch. Everything else works including the AUX pump. I can run a hot wire to the main pump and run the genset but would like to have this unit “turnkey”. I removed the switch and checked for continuity everything seems correct. My main question is what wires feed the main pump. I used a jumper wire and could control everything through the switch but still can’t find the main fuel pump wire. T I A !

 

[kloppk]

Have you downloaded the -24 TM and checked the schematics.
All the wiring info is there from S1 to the Fuel Pump.

 

[Chanderson69]

I have not. I struggle trying to find the link for that

 

[kloppk]

Here ---> MEP-803A TMs From the TM Section of this forum

 

[Chanderson69]

After racking my brain on this TM. I can’t figure out what the wire number is that actually feeds into the main fuel pump. I see that post 3 is common but still unsure where it leads from there into the pump itself

 

[Light in the Dark]

Check out the colored DC schematic someone put together: https://www.steelsoldiers.com/attachments/5-10kw-tqg-colored-dc-schematic-pdf.888643/

It should help guide you on where the fuel pump (E2) ties to.

 

[Light in the Dark]

So just to confirm, when you unplug the fuel pump from the harness near the radiator, with the S1 start switch set to PRIME + RUN, you have tested the harness side connector to confirm there is no voltage present?

I only ask because I just had to yank an airtex fuel pump out of a newly rebuilt machine, that made no noise at all but was energized (it was dead).

 

[kloppk]

Also the second attachment in the following link may be of some help.
Annotated DC schematic

 

[Chanderson69]

So just to confirm, when you unplug the fuel pump from the harness near the radiator, with the S1 start switch set to PRIME + RUN, you have tested the harness side connector to confirm there is no voltage present?

I only ask because I just had to yank an airtex fuel pump out of a newly rebuilt machine, that made no noise at all but was energized (it was dead).

Thank you for the colored schematic. And yes I check for power at the plug. I know the pump works when I send power to it. I will work on it in the morning with the new diagram. Thank you all