MEP-805B Will not Start

[Guyfang]

Indeed. The gov is not giving the signal to the Actuater. Did you adjust the mag pickup? If so, and still no signal to the Actuater, then the problem is in the control panel. So, what controls the speed, guys?

 

[155mm]

what happens if you start it with the hot wire, then connect the original wire on the actuator? does it stay running? did you check the ohms on the actuator? says 7.8 ohms for 24v.

 

[155mm]

Do you think he could have a loose connector on the back of the cubical? or the speed control unit not making good contact to the back plane, but the other stuff works on the speed control.

If it were my ginger, I would take the cubical off, take the backplane out, remove and inspect the speed control unit, verifying that the nuts that hold the scu are present and tight when reassembling, and like baxter said, use the goop

 

[jfpf6061]

what happens if you start it with the hot wire, then connect the original wire on the actuator? does it stay running? did you check the ohms on the actuator? says 7.8 ohms for 24v.

No it does not. As soon as I remove the hot wire it dies. I checked ohms and actuator is okay. I do not have required voltage at the white wire while cranking to supply the actuator and adjust speed accordingly.

 

[jfpf6061]

Do you think he could have a loose connector on the back of the cubical? or the speed control unit not making good contact to the back plane, but the other stuff works on the speed control.

If it were my ginger, I would take the cubical off, take the backplane out, remove and inspect the speed control unit, verifying that the nuts that hold the scu are present and tight when reassembling, and like baxter said, use the goop

I have the cubicle off and have removed, cleaned, and tightened all connections, backplane, and terminals.

 

[jfpf6061]

Indeed. The gov is not giving the signal to the Actuater. Did you adjust the mag pickup? If so, and still no signal to the Actuater, then the problem is in the control panel. So, what controls the speed, guys?

I did adjust the mag pickup and that is lighting on the speed control when I crank now. DC power is on and the speed sensor light is on when I crank. Nothing else.

 

[155mm]

Are any of the rheostats set to 0 on the speed control unit? Remember they only operate from 7oclock postion to about 4oclock. I would note where they are now, and attempt to adjust any and all.

you checked ohms from p5 to mpu, did you check ohms form p5 to actuator? p5 o to red, p5 y to white

 

[jfpf6061]

Are any of the rheostats set to 0 on the speed control unit? Remember they only operate from 7oclock postion to about 4oclock. I would note where they are now, and attempt to adjust any and all.

you checked ohms from p5 to mpu, did you check ohms form p5 to actuator? p5 o to red, p5 y to whiteView attachment 728519

None of the rheostats are on 0. I did check continuity not for resistance there on wires to actuator from P5.

 

[155mm]

Did you exercise the rheostats? Up down to clean our any dust dirt rocks, i think I remember 5 on that box

 

[jfpf6061]

Did you exercise the rheostats? Up down to clean our any dust dirt rocks, i think I remember 5 on that box

Yes I did do that. I will try again. Can the I/O module have anything to do with this?

 

[155mm]

Indeed. The gov is not giving the signal to the Actuater. Did you adjust the mag pickup? If so, and still no signal to the Actuater, then the problem is in the control panel. So, what controls the speed, guys?

the speed control unit, thru the backplane.

1st guess would be connection between the scu and the backplane.

2nd, my uneducated cant put my hands on it guess is.... a pot took a crapola, because a 200lb gorilla with a skrew driver wearing green coveralls was dinkering where he shouldnt have been, and over clocked a rheostat. (not you Jim, an army mech)

let me sleep on it, will give you another guess tomorrow

It could be the I/O, everything goes thru it

 

[Guyfang]

I love it when you guys are on a roll. And first guess would be speed control. If the gen set is new to you, look at the component, and Make sure it's a 60 hertz component. The reason I ask, is that this happens sometimes, and its an easy thing to check. I do not remember if anyone ever asked if the set is a new to you set, or if you have ever seen it work right. Because if its is new, or you have never seen it work right, EVERY component is suspect.

Yes, the I/O can be the problem. Every bad one I replaced, looked as good as the new one I put in. I have never seen damage/burns of any type.

 

[jfpf6061]

Good Morning,

Attached is an image of the governor label. Little blurry but readable.

 

[155mm]

Did you disconnect the batteries when you pulled the cubical off? have the batteries been disconnected since reinstalled and start attempts?

another thread to read, doesnt apply to starting but does apply to the computer side of this genny

https://www.steelsoldiers.com/showthread.php?158277-MEP-805B-display-problem-found&highlight=

 

[155mm]

Guy did a very detailed write up about how to use the parts manual (TM) and how to use the UOC (user on code?) I cannot find it but everyone needs to learn how to use that part of the manual.

ok this is the crash course of UOC's, in the front of the manual it says LTX is 50/60hz and LTY is 400hz. you want parts that are LTX

View attachment 728581

next is the parts page... item 61 has 2 different part numbers, so how do you know which one you want... UOC.. LTX

View attachment 728582

I am not a very good teacher in typing, I am a more show you than tell you. Thats the best I can do.

 

[155mm]

Good Morning,

Attached is an image of the governor label. Little blurry but readable.View attachment 728569

Well i learned something new today. the SCU is the same for the 400 and 50/60 hz motor, I guess that makes sense, its only controlling the motor, has nothing to do with the generation side

 

[jfpf6061]

Yes. I disconnected batteries several times. Batteries are full charge. I am aware of usable on codes. In a past life I was a motor sergeant and thought I got away from this stuff but here I am 20 years after I retired playing around with used military generators that were not even in the inventory when I served. Oh well...fun, fun, fun,,,My day is always exciting at work.

Jim

 

[GIJoeCzar]

Gents, I have similar issues with my MEP-805b, and have read through the threads -- just wondering if my genset problem is obvious to anyone out there. My MEP-805B cranks, but wont' start. I have good fuel pressure all the way to the fuel shut off actuator on top of the injector pump. I did ran the test to the fuel shutoff solenoid lead and got correct readings (correct ohms and no continuity). I checked the female side of the fuel solenoid plug and got no reading -- nothing -- when cranking the motor. I jumped the fuel solenoid, got he familiar metallic "click", and the motor fired right up. So, what I know is that the generator is not sending the correct signal (no signal actually) to the fuel shut off solenoid. I've done the correct start up procedure, holding the fault switch for two seconds before I crank, so it's not an operator head space and timing issue. The CIM displays no errors, but while booting shows an "Port reads 78 ... Cable disconnected ... " message. I have not yet removed the backplane and done the recommended cleaning, but will do so. Again, just wondering if anyone has had the same issues, with the same "Port reads 78 ... Cable disconnected ... " message … just hoping I can save some time. Thanks much!

 

[GIJoeCzar]

MEP-805B Won't Start

Here are a few relevant photos.

 

[GIJoeCzar]

For the love of God, I've been away from this site for so long that I no longer remember how to post photos ...