MEP-803A getting it to work,,,my first one!

[kloppk]

Me
kloppk here on the SS forum

 

[WWRD99]

Ok so it has been years since I posted on this thread about my genset but it has been running great with no issues yet. The storm coming had me go out to do an overnight run on it but the low fuel level light comes on and it won't run the fuel pumps. The tank is almost full, about 2 inches from the top of the filler neck cap. Is there a way to bypass that level sensor up at the start switch or relay so I can get this going fast since time is not on my side for shipping parts? I may try and suck all the fuel out and try and move the level sensor up by hand. If that doesn't work I would need a basic wire jump if possible. I can't find a thread on that if there is one. Thanks for all the help with this genset.

 

[Guyfang]

It may not be the level sensor. Could also be the A9. I would take the panel off the front and pull the level switch out and see of its just the float stuck or broken. Then if not, you can start to hot wire.

 

[Guyfang]

I THINK, if push comes to shove, you could take the cap off the Diagnostic Connector, use a wire to jump from pins K and P, and the fuel pump should run. @kloppk check me out here.

 

[Guyfang]

I edited the above post. Pins P & K might be better.

 

[kloppk]

I think jumping K to P isn't going to work. P is the START signal. That jumper would not inhibit the Low Fuel

Two methods come to mind.
1) Remove the cover by the fuel tank and disconnect P15 from J15 on the harness from the A9 module.
Doing so will also prevent the Aux Fuel pump from working.

2) A more drastic method would be to disconnect the Fault Monitor.
** Doing so will prevent any actual faults from shutting the generator down.

 

[Light in the Dark]

In a real pinch there is a way to start the machine with the BATTLE SHORT, just realize you are flying blind on almost all shutdown faults at that point.

With that said, if you disconnect the double float switch, you can jumper it out of the circuit. From testing section on the Fuel Float Module

Testing.
...
Tag and disconnect fuel float module (20, FIGURE 2-21 ) electrical connector (J12) from fuel float switch electrical
connector (P12).
Connect pins 1 and 2 of fuel float module electrical connector (J12) together with a jumper wire.
Connect negative battery cable, move MASTER SWITCH to PRIME & RUN AUX FUEL position and auxiliary fuel
pump should start operating. Remove jumper wire and auxiliary fuel pump should stop operating.
Start and operate generator set at rated voltage and frequency.
...

 

[WWRD99]

I edited the above post. Pins P & K might be better.

Ok I did try this but it still turned on the low fuel light and turned off the pump. I did pull the panel and unplugged the low fuel float sensor and the main fuel pump does stay on now but no aux pump. I do have this genset hooked up to a 300 gallon aux tank, so it would be nice to get the aux pump to turn on once it got low. There are 4 wires. 2 black and 2 red.

The picture you posted has the float system in it but I don't see the plug and pin locations for each float. You happen to have that handy? The 2 black wires have continuity now and the 2 red wires do not. The picture of it shows that the low fuel closes at low fuel and the aux pump closes at 1/3 of a tank.
My tank is full to the top. I can't see the wire colors on that picture of the pumps to know which wires go to which sending unit. I am assuming, since the genset low fuel light comes on when plugged in, that the 2 black wires go to the low fuel sending unit.

I am thinking of jumping the 2 red wires together, following pin locations, in the float level connector. I may de-pin the black wires too. They don't look that hard to pop out. Can you confirm that the 2 black wires go to the low fuel light sensor? I haven't located a new float setup yet either. I am not sure if they are available. Thanks again for all your help.

 

[WWRD99]

Ok I cut the outside black wire on the float connector and it runs fine with the float switch plugged in. I am not sure if the aux pump will turn on yet. I did not hear it turn on with the start switch in prime. I can't remember if it does with the tank full but I am thinking it does not. I am now on the hunt for a repair for the float system. I do run this for 24 hours when I do the test run with a load on it with the house so I would like the low fuel setup to work.

 

[Light in the Dark]

Aux pump is only energized at the low position... A full tank will keep it silent.

 

[WWRD99]

Aux pump is only energized at the low position... A full tank will keep it silent.

That's what I thought! I haven't had a problem with the aux pump working so I am hoping that keeps goin that way. You have any spare level sensors or a way to replace the floats?

 

[Light in the Dark]

Its not the floats that fail (they do get stuck from time to time with tank goop... which may have happened with your set) but the internal magnets short in them causing the DC fault primarily.

An SS user was working up a civilian retrofit for this part, but since I haven't seen it come to market yet.. it must still be simmering on the stove

I might have something, new or used. This part is going to be a difficult one as the OEM wont entertain small orders, and wants over $250 each in VOLUME.

 

[WWRD99]

Its not the floats that fail (they do get stuck from time to time with tank goop... which may have happened with your set) but the internal magnets short in them causing the DC fault primarily.

An SS user was working up a civilian retrofit for this part, but since I haven't seen it come to market yet.. it must still be simmering on the stove

I might have something, new or used. This part is going to be a difficult one as the OEM wont entertain small orders, and wants over $250 each in VOLUME.

Ok that does make sense. I have not gotten a look inside the tank yet to see if the actual float was still in one piece, was thinking it was stuck down. My tank is clean and not gunked up. I will let the tank run low and stick my hand in there and see if the float is damaged. I can make a float and use the old metal rods in it. I can look into a magnet style float switch as well. They aren't that tough to put together. I have seen a few videos about the float coming apart and the metal rods that make the magnet work fall into the tank.

 

[Light in the Dark]

There are two floats on this unit, one ON and one for OFF. If you pull the rear cover and take the assembly out of the tank, you can move the floats by hand, and see if the fault goes away. I am betting its an internal short though.

 

[Guyfang]

There are two float systems in the tank. The sender for the gauge, and yes, you could make a float for it with can or other object. But it has absolutely nothing to do with your problem. Like LITD wrote, the other float is normally a non repairable item. There are civilian replacements for it.

 

[WWRD99]

There are two float systems in the tank. The sender for the gauge, and yes, you could make a float for it with can or other object. But it has absolutely nothing to do with your problem. Like LITD wrote, the other float is normally a non repairable item. There are civilian replacements for it.

So I am on the understanding that the low fuel shut off is the lower float on the s style sending unit. My fuel gauge has never worked and probably need a new sending unit for it yet. I have seen a few of them like this and on his video as well. He got a new one in the repair but have all since run out of stock. The new style float doesn't look that hard to make or buy.

 

[Light in the Dark]

That double float has nothing to do with the fuel gauge, FYI... its only for regulating the AUX PUMP when S1 is in the AUX setting.

 

[Guyfang]

There is another float in the tank for the gauge. If the gauge doesn't work, pull it out, and check it.

 

[WWRD99]

That double float has nothing to do with the fuel gauge, FYI... its only for regulating the AUX PUMP when S1 is in the AUX setting.

Yup I have played with the fuel gauge sending unit years ago but didn't care if it worked. The lower float in the pic is the one that works the aux pump is the one I was thinking of fixing since you can't buy the part anymore.

 

[Tinstar]

This is the civilian marine fuel float that fixed my non working fuel gauge.
Stainless Steel
KUS SSS-8.5
About $40-45
Their available on eBay or any marine store.

Installs without having to remove tank and works great. Fuel gauge now works.

EDIT:
This part is also the correct ohms for the gauge and was recommended to me when I was getting my 803A going.
Thanks to all the guys who helped with advice, direction and parts.