Yet another MEP-802a "No Fuel" thread

[MrShawn305]

So my 802a has always shut down with a "no fuel" fault. I always keep it full, and I always verify plenty of fuel when it does this. After reading a bunch of threads, I ordered a fuel switch. Sometimes the unit would run hours without tripping, other times it would do it almost right away. The last time I ran it, it shut down and I restarted it. It immediately tripped again. So I repeated, and almost before I could hit the battle short, it tripped again.

Fast forward to today, I replaced the switch and adjusted to 1/16" off the bottom of the tank. (Anywhere from 1/16" to 1/4", hard to tell when adjusting.) I started it up to test, and I'm still getting the same issue. It will run for a few minutes and then shut down with "no fuel" fault. I reached into the tank and made sure the float isn't touching on anything and is moving freely.

Some notes: The old float was intact for the most part with all of the magnets. If I reached in and pushed the float down, the unit would shut down every time. It would also trigger the aux fuel pump when the correct float was pushed down. What else should I test? I'm considering taking the old switch, connecting it up and hanging it off the unit with the two floats taped securely into the "up" position. Just to see if it makes a difference. Any advice?

 

[Light in the Dark]

Have you tested the fuel module on the RR fender, which attaches to the float mechanism? Only two ways I know of to get a no fuel trip, and its the double float assy, and the fender mounted switch. Testing of these is covered in the TM.

 

[MrShawn305]

Have you tested the fuel module on the RR fender, which attaches to the float mechanism? Only two ways I know of to get a no fuel trip, and its the double float assy, and the fender mounted switch. Testing of these is covered in the TM.

I had not. I did come up with an interesting development though. And some additional notes. So when the fault occurred this time, I was not able to reset the fault. It would just stay lit. So I unplugged the float switch, and was able to reset the fault light. While the unit was still running, I checked continuity on the black pair (what I traced on the other switch to the low fuel) and got a consistent 0 ohms. I shut down the unit, with the switch still unplugged, and now I am getting open circuit just like the aux switch. I'm going to readjust the float switch, but I think I have a vibration issue in this thing that is enough to cause the low fuel switch to trip out.

The old switch appears to have been rubbing on the bottom of the tank. Other than that, it seems to test out good.

 

[MrShawn305]

Ok, so I found something a little bit interesting. I noticed earlier that there is a bolt with a foot or something at the bottom of it that sits on top of the fuel tank. That seems to have been adjusted too far down and the top of the tank is bowed in. Why does that matter? I stuck my arm in the tank again for some more "in depth" (pun intended) investigation into this issue. I found that there is a hump that goes left to right inside the tank. I think I remember this being mentioned in another thread, but I wasn't visualizing it like this. SO with the top of the tank being bowed, it was pushing the bottom of the switch assembly closer to that hump. So. With the compression nut loose, I used my left hand to position the float inside the tank to the ideal position for maximum clearance while also trying to set the 1/16" height. I checked continuity and got none. Started it up, checked again and still none. Kept the leads on the connector for a good while while running. Nothing. Sweet, so I shut her down, plugged it back in and started it up. I have it running the house right now to see if I get the light back. If it seems good, I'll let the sucker run all night and see what happens.

Not sure if you can see it well in the pic, but the tank is bowed pretty good.

 

[CallMeColt]

I had your issue & got two switches. Drove me nuts. Seems like you are almost there. What I found was the rotational adjustment needed to be better. The vibration would cause a false fault. Loosen the nut & rotate each way until the float hits. Find the middle. Then, push it down until it hits the bottom of the tank. Then go up your 1/4in. Make sure it doesn't move while tightening.

 

[MrShawn305]

I had your issue & got two switches. Drove me nuts. Seems like you are almost there. What I found was the rotational adjustment needed to be better. The vibration would cause a false fault. Loosen the nut & rotate each way until the float hits. Find the middle. Then, push it down until it hits the bottom of the tank. Then go up your 1/4in. Make sure it doesn't move while tightening.

That's exactly what I did. Seems like it's working now so I fueled it up and buttoned it up as we have some weather coming in this weekend. I still need to do the two well nuts. But I goofed and only ordered one as I didn't realize there were two. So as soon as I get the second one, I'll drain the tank and get those swapped out.

 

[Light in the Dark]

There is some wiggle room, but not a lot. A tank that has been reefed down a bit too much can distort a number of things (and yes, knowing that step is in the tank is pretty important to). Its not like that tank has a whole lot of places it can go where its located (and how its shaped)!

I hope the issue rectifies itself with your adjustments. I actually set the floats a bit higher than that if I need to change this, just because I know things move a little bit under use.

 

[Light in the Dark]

That's exactly what I did. Seems like it's working now so I fueled it up and buttoned it up as we have some weather coming in this weekend. I still need to do the two well nuts. But I goofed and only ordered one as I didn't realize there were two. So as soon as I get the second one, I'll drain the tank and get those swapped out.

You should seriously consider doing the ultimate well nut mod if you need to swap the nut. Its more expensive, and more work... but it will outlast you.

 

[MrShawn305]

You should seriously consider doing the ultimate well nut mod if you need to swap the nut. Its more expensive, and more work... but it will outlast you.

I did see that repair and plan to. I ordered the one bulkhead, but didn't realize I needed two. So after I get the second one, I plan to do that. That's an awesome fix!

 

[Light in the Dark]

Unless you trailer the set around, I have no issue with just using a regular well nut on the top of the tank. But if you have the time and desire, do them both.

 

[CallMeColt]

Cool, hopefully the adjustment did it. Takes some times to work out the kinks on these things but once you do, it works very well.

 

[Guyfang]

You are lucky the tank hold down bolt is even there. Lots get "lost" in the wash, so to say.

Something else you guys should note. The bolt of the fuel tank hold down, SHOULD have a plastic "shoe", or "foot" on the bottom. Yours is there. Many are missing. Thats the way they all came. That way, the metal bolt can not wear a hole in the tank. Seen it several times. The foot was missing, and the vibrations wore a hole in the top of the tank. Do not bother looking for the bracket, hold down, or foot. Its not in the -24 parts TM. Or I never found it anyway. And I looked, several times. For a plastic "foot" covering, I simply used a plastic cap from a plastic coke bottle.

 

[Chris454]

I recently had the same issue. I ordered a new switch and installed it and the low fuel light tripped again. I zip tied the float in the up position and plugged the switch in out side the tank and it ran perfect for hours so I was fairly confident the switch was good. Ultimately the problem was the float was too close to the step down in the tank and it was getting stuck. It was my error when I reinstalled the switch after doing the ultimate well nut upgrade. I guess the best way to learn is to make a mistake then figure out what you did wrong. I also upgraded the fuel sender while I was diagnosing the low fuel cut off.