802-a fuel gauge

[JimmyLet58]

I put a new fuel gage in and it pegs all the way past full. I also just put a new 5.5 wema fuel sending unit in and gauge still reads the same. Not sure what is wrong. I hooked the 2 wires up. Can anyone tell what I got going on. Thanks

 

[Guyfang]

Is this how your Meter is hooked up? You checked? Twice?

​	​	​	​	​	​
​	​	M5 Fuel Level Indicator​	​	​
From​	Wire #​	Wire #​	From​
M6-I​	137H​	I​	I​	137F​	TB6-4​
J7-1​	128B​	S​	G​	100AR​	M6-G​
​	​	​	​	​	​

And the sender? Checked it twice?

 

[JimmyLet58]

Thanks for the diagram I will definitely check it out!

 

[Guyfang]

If you do not have the TM's downloaded from the Forum, here is the place:

All the manuals for the MEP-802, 5KW Generator

This should be the whole package of information needed to work on/repair the MEP-802 Generator set.

www.steelsoldiers.com

 

[JimmyLet58]

If you do not have the TM's downloaded from the Forum, here is the place:

All the manuals for the MEP-802, 5KW Generator

This should be the whole package of information needed to work on/repair the MEP-802 Generator set.

www.steelsoldiers.com

Thank you!

 

[Guyfang]

Keep in mind, the MEP-802A and the MEP-803A are almost like twin brothers. One has 2 more jugs, that's all. The schematics are interchangeable.

 

[Ray70]

Be careful and double check the wiring on the gage. The original gages on the older 802's are different than the newer Faria Beede gages, the "S" and "I" terminals are on opposite sides of the gage, so make sure its wired correctly.
Also, looking at Guy's diagram above. You should have +24V on the "I" terminal, -12V on the "G" terminal and the "S" terminal goes to the sending unit.

 

[Evvy Fesler]

In my 804 TM is a test procedure that will let you know if the gauge is bad. I didn't look, but yours probably has a test procedure, too.

Are you sure that your float isn't hung up on something and stuck in the "full" position?

 

[JimmyLet58]

In my 804 TM is a test procedure that will let you know if the gauge is bad. I didn't look, but yours probably has a test procedure, too.

Are you sure that your float isn't hung up on something and stuck in the "full" position?

I just put a new wema 5.5 in the tank so it should be good. And the fuel gauge is new. So I have to check my wiring to the gauge. I can hardly see the numbers on the wiring to the gauge. Thanks

 

[Guyfang]

Go farther up the wire. The number is repeated every so often.

 

[Evvy Fesler]

Go farther up the wire. The number is repeated every so often.

@Guyfang - you’ve been around for awhile. What does that little typewriter for the wires look like?

 

[Guyfang]

No idea. Would be of interest. I would assume, always a risky thing to do, but assume its sprayed on the wire, not printed.

 

[JimmyLet58]

Be careful and double check the wiring on the gage. The original gages on the older 802's are different than the newer Faria Beede gages, the "S" and "I" terminals are on opposite sides of the gage, so make sure its wired correctly.
Also, looking at Guy's diagram above. You should have +24V on the "I" terminal, -12V on the "G" terminal and the "S" terminal goes to the sending unit.

Hey Ray
I che check all my wires on the gauge. The best I can tell the I terminal has 2 wires 137 H20 & 137 F20 the ground has 100AR and the S terminal has wire 128 B
I am showing with the unit running the I terminal showing 27.6 v and the S is 6.8 v
I'm not getting -12v on the G as you stated. Showing 0.1 I think.
Thank for everyone help and information

 

[Ray70]

Maybe you are misunderstanding what I meant. The G terminal is eventually connected to the negative of the battery as is the entire chassis of the machine.
G stands for ground... chassis ground, not earth ground.
If you put your meter black lead on "G" and the red lead on "I" you should show +12V if not you have a ground problem at the gages.
You should also have continuity if you measure resistance from "G" to any bare metal chassis point.

 

[JimmyLet58]

Maybe you are misunderstanding what I meant. The G terminal is eventually connected to the negative of the battery as is the entire chassis of the machine.
G stands for ground... chassis ground, not earth ground.
If you put your meter black lead on "G" and the red lead on "I" you should show +12V if not you have a ground problem at the gages.
You should also have continuity if you measure resistance from "G" to any bare metal chassis point.

Thanks Ray I will check it out again. I may have it wrong at the new wema fuel gage. I noticed when I took the old float out one wire was mounted on the top of the float unit sending wire and other was ground to one of the screws for ground. I took the two wires from the float sending unit and hooked each wire up. Was I still supposed to ground that wire like was on the old float? Sorry I am not electronically inclined lol.

 

[Evvy Fesler]

That’ll do it! Put the ground back under the screw.

 

[Ray70]

No, no.... with the Wema gage it sounds like you did it correctly. I normally attach the reddish colored wire to the wire that was on the sense wire of the old gage and connect the black wire to the old ground wire, but to be honest the Wema is just a resistor, so the polarity doesn't matter.
The old gage has 1 wire and the body is grounded, the new WEMA sensor has 2 wires so the body is not grounded.

 

[Ray70]

Oh, and one other thing to check... once you verify the gage wiring and ground are good, if you disconnect the "S" wire from the gage and measure resistance from the S wire to ground you should get somewhere between 30 and 240 ohms, depending on how much fuel is in the tank.
If everything checks out but the gage is still pinned, look closely at the gage. I know at least the Faria Beede gages can get stuck if they peg all the way up or down. The needle will usually hit the side of the housing and get stuck.
To fix it, loosen the nuts on the long mounting studs and tap the gage sideways against your palm, that should jar the needle loose.
tighten the nuts, reinstall and try it again.

 

[maniatopoulosg]

I put a new fuel gage in and it pegs all the way past full. I also just put a new 5.5 wema fuel sending unit in and gauge still reads the same. Not sure what is wrong. I hooked the 2 wires up. Can anyone tell what I got going on. Thanks

I just went threw this
Wasted a lot of money at the end of it all my gauge was not correct
I came across a new gauge from zed254


Sent from my iPhone using Tapatalk

 

[Zed254]

I just went threw this
Wasted a lot of money at the end of it all my gauge was not correct
I came across a new gauge from zed254


Sent from my iPhone using Tapatalk

Here is where I bought my last fuel gauges: https://armysurpluswarehouse.com/military-issue-fuel-gauge/ . I mounted one on my 802.