MEP-805B Aux fuel pump

[SteveTheGreen]

The auxiliary fuel pump quit working on our MEP-805B. Fuel line is not obstructed. Pump seems to get power. We swapped the fuel pump with a known good one. Ideas?

 

[Guyfang]

Have you downloaded the TM's. And looked at the troubleshooting? The Aux fuel pump is controlled by a float switch. If the pumps works when you hook 24 volts up to it, then the next logical step is to check the MT5 Fuel level sender.

 

[mciikurzroot]

The auxiliary fuel pump quit working on our MEP-805B. Fuel line is not obstructed. Pump seems to get power. We swapped the fuel pump with a known good one. Ideas?

Have you checked for actual voltage being present at the Aux pump connector, thereby if real voltage is present then the pump would / should be sucking fuel from an outboard source. Now REMEMBER this set does not have real fuel float SWITCHES like we are more used to, there is ONE only fuel2 wire level measuring system this same system also serves at a predetermined setting reading as a percentage % of the tank capacity and typically YOU CAN'T change this setting it is a part of the computer programming that you don't have access to or the software to manipulate the factory settings.. This fuel measurement scheme is a simple stick and at frequent spots measures the resistance from 30 odd ohms to 240 or so ohms resistance the higher the number the lower the fuel level. So back to your problem, if your being supplied 24vdc at the actual pump connector and the pump is not operating, well then we know what is wrong, to confirm this apply 24vdc to the actual pump, the pump is polarity sensitive, so plus to the red side and minus to the black side ..not much more to test, this procedures/s will prove up your real situation.. but if you never receive a call for the voltage being sent to the pump, then you just need to work around it and know this part of your CIM has failed and your CIM will fail, its just a matter of time and circumstances, but that's a whole new set of circumstances.. One more test to be sure, ?? With the set NOT RUNNING, go to K19 terminal 7 and apply PLUS voltage, this voltage will or should find its way to the RED side of the Aux pump .. if you want to dig into this to the smallest degree write me back, but overall this is a good series of test to apply and prove or disprove your system...
best and have fun: mac/mc

 

[SteveTheGreen]

Have you checked for actual voltage being present at the Aux pump connector, thereby if real voltage is present then the pump would / should be sucking fuel from an outboard source. Now REMEMBER this set does not have real fuel float SWITCHES like we are more used to, there is ONE only fuel2 wire level measuring system this same system also serves at a predetermined setting reading as a percentage % of the tank capacity and typically YOU CAN'T change this setting it is a part of the computer programming that you don't have access to or the software to manipulate the factory settings.. This fuel measurement scheme is a simple stick and at frequent spots measures the resistance from 30 odd ohms to 240 or so ohms resistance the higher the number the lower the fuel level. So back to your problem, if your being supplied 24vdc at the actual pump connector and the pump is not operating, well then we know what is wrong, to confirm this apply 24vdc to the actual pump, the pump is polarity sensitive, so plus to the red side and minus to the black side ..not much more to test, this procedures/s will prove up your real situation.. but if you never receive a call for the voltage being sent to the pump, then you just need to work around it and know this part of your CIM has failed and your CIM will fail, its just a matter of time and circumstances, but that's a whole new set of circumstances.. One more test to be sure, ?? With the set NOT RUNNING, go to K19 terminal 7 and apply PLUS voltage, this voltage will or should find its way to the RED side of the Aux pump .. if you want to dig into this to the smallest degree write me back, but overall this is a good series of test to apply and prove or disprove your system...
best and have fun: mac/mc

I need to do this. Need to know how first. Ha!
I do hear the ticking sound when it's powered up. The fuel guage display on the generator works. So, something is measuring fuel in the tank.
So, the dipstick and pump are not talking? Guess I need to pull out the schematics to figure out where the disconnect is.

 

[SteveTheGreen]

Turns out the fuel line was clogged.

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[mciikurzroot]

Thanx for sharing this annomally , clogged ? with what is the next question pease.. best: mac/mc MCII

 

[SteveTheGreen]

Well, the guy that set up our system used hydric hose. Found out diesel dissolves this hose. Replaced with diesel line and all is well.

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[SteveTheGreen]

I took an air hose and blew out the control box. This fixed the mouse. This time it cured the sux pump.

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