MEP805B not generating

[Southernman13]

New to forum. I’ve had this for about 5/6 years and it’s my first time fooling with it. Got it running. Runs like new. 1200 hr unit. Took a while to figure it out. Couldn’t get it to turn over at all and the fuel level indicator was showing full tank but it was maybe 1/4 tank. Well I didn’t have the dead crank/normal switch turned to Norma. Once I did that I got it running. When I switched it to normal the fuel indicator corrected itself. Wall was good but won’t generate and the battle short mode is on with the battle short switch off. There is a message on the board that says low oil pressure check pressure switch etc. I did some checking with my 24v test light. In auxiliary fuel tank mode I have no power to the fuel pump. I do have power on the back of the rotary switch. And the fuel tank indicator is back to full. So I have no power to the fuel pump the fuel tank sending unit and the oil pressure switch. I switched out the start really and fuel pump really but no change there. So is the battle short on because it says low oil pressure ? And it won’t generate. When u rotate to start to energize it sounds like it wants to kick on. But it doesn’t. It puzzles me because when I first found out to switch it to Normal the fuel pump came on and the fuel gage corrected itself. I’m that’s no longer working. Sorry for the long post. Thanks

 

[Mullaney]

New to forum. I’ve had this for about 5/6 years and it’s my first time fooling with it. Got it running. Runs like new. 1200 hr unit. Took a while to figure it out. Couldn’t get it to turn over at all and the fuel level indicator was showing full tank but it was maybe 1/4 tank. Well I didn’t have the dead crank/normal switch turned to Norma. Once I did that I got it running. When I switched it to normal the fuel indicator corrected itself. Wall was good but won’t generate and the battle short mode is on with the battle short switch off. There is a message on the board that says low oil pressure check pressure switch etc. I did some checking with my 24v test light. In auxiliary fuel tank mode I have no power to the fuel pump. I do have power on the back of the rotary switch. And the fuel tank indicator is back to full. So I have no power to the fuel pump the fuel tank sending unit and the oil pressure switch. I switched out the start really and fuel pump really but no change there. So is the battle short on because it says low oil pressure ? And it won’t generate. When u rotate to start to energize it sounds like it wants to kick on. But it doesn’t. It puzzles me because when I first found out to switch it to Normal the fuel pump came on and the fuel gage corrected itself. I’m that’s no longer working. Sorry for the long post. Thanks

.
Welcome to the outfit!

So, I guess I just can't read very well or maybe I am just not understanding what you said. Short sentences for us old guys please

I am hearing that the power - the motor - is not functional. Right?
Battle Short on.
Starter just clicks?

Have you verified battery voltage?
Have you checked the connections on the battery?
Remove, Clean, Etc?

Report back please?
.

 

[Southernman13]

.
Welcome to the outfit!

So, I guess I just can't read very well or maybe I am just not understanding what you said. Short sentences for us old guys please

I am hearing that the power - the motor - is not functional. Right?
Battle Short on.
Starter just clicks?

Have you verified battery voltage?
Have you checked the connections on the battery?
Remove, Clean, Etc?

Report back please?
.

I’m sorry I know I’m confusing. Trying to supply as much info as I can but it’s just to confusing. It starts and runs perfect. This is what the screen reads when running the generator part won’t turn on when u bump the start mode to excite the fields nothing changes

 

[Southernman13]

I’m sorry I know I’m confusing. Trying to supply as much info as I can but it’s just to confusing. It starts and runs perfect. This is what the screen reads when running the generator part won’t turn on when u bump the start mode to excite the fields nothing changes View attachment 903320

Did I scare u off? Lol. Any help or ideas would be great. Thanks

 

[peapvp]

After starting engine place switch back to run / prime, wait 5 seconds and place the Engine control switch back to “Start” for 2 to 4 seconds then place switch back to run / prime

report back

Note:
There are several plaques placed throughout the entire generator
One off them has the correct starting and shut down procedures
Plaques are installed on all doors

 

[Southernman13]

Did that many times. It did sound like the engine was tried to rev ever so slightly when o did this. Now it doesn’t sound like it’s trying to do anything.

 

[peapvp]

It shouldn’t sound like anything, the field flash has no sound.
The only thing you should see is the voltage going up on the display and power available on the convenience receptacle.

My suggestion would be to download the TM’s and then read them and deeply familiarize yourself with all the LED’s on the back plane circuit board, Automatic Voltage Regulator and Governor Controller
That’s what they are there for and their individual meaning is explained in the TM’s

 

[Southernman13]

It shouldn’t sound like anything, the field flash has no sound.
The only thing you should see is the voltage going up on the display and power available on the convenience receptacle.

My suggestion would be to download the TM’s and then read them and deeply familiarize yourself with all the LED’s on the back plane circuit board, Automatic Voltage Regulator and Governor Controller
That’s what they are there for and their individual meaning is explained in the TM’s

Ok thanks. What I meant by sound was the motor sound like it was laboring a little bit when I hit the start to excite the generator sound like it was trying to do something but it didn’t and now it doesn’t sound like that maybe I was just hearing things kind of like when you’re mowing with the lawnmower and you hit a patch of grass and it will sound like motor changes of RPMs a little bit kinda to that effect is what it was

 

[peapvp]

Ok thanks. What I meant by sound was the motor sound like it was laboring a little bit when I hit the start to excite the generator sound like it was trying to do something but it didn’t and now it doesn’t sound like that maybe I was just hearing things kind of like when you’re mowing with the lawnmower and you hit a patch of grass and it will sound like motor changes of RPMs a little bit kinda to that effect is what it was

i understand.

 

[peapvp]

My suspicion, without any further proof / testing and not being in front of the Genset myself with you while you are doing this field flash, I would say it points to a bad Automatic Voltage Regulator.
Before you run out and buy a new AVR, please share which LED’s are on, dimm or blinking on the AVR, when you start the Genset, when Genset is running and then when you do the field flash.

There are two different versions of the ECS TCM100
The first version does the field flash while the engine is cranking / starting at about 666 rpm through governor controller and TCM100 in conjunction with Relay K15
The second version requires a manual field flash after the Genset is running by placing the ECS switch back to start for 2 to 4 seconds

 

[Southernman13]

My suspicion, without any further proof / testing and not being in front of the Genset myself with you while you are doing this field flash, I would say it points to a bad Automatic Voltage Regulator.
Before you run out and buy a new AVR, please share which LED’s are on, dimm or blinking on the AVR, when you start the Genset, when Genset is running and then when you do the field flash.

There are two different versions of the ECS TCM100
The first version does the field flash while the engine is cranking / starting at about 666 rpm through governor controller and TCM100 in conjunction with Relay K15
The second version requires a manual field flash after the Genset is running by placing the ECS switch back to start for 2 to 4 seconds

Ok I went to the green mountain web site. Very informative. Thanks. So I figured out that my oil pressure switch isn’t getting power to the black wire. Supposed to have 1-5volts while running. There’s a wiring schematic in back of manual. I can find the switch and the wires in it but I have no idea how to follow it from there. I’m stuck again lol. Any help would be great. Thanks

 

[Guyfang]

show us a picture of the switch and wires on a schematic.

 

[peapvp]

Ok I went to the green mountain web site. Very informative. Thanks. So I figured out that my oil pressure switch isn’t getting power to the black wire. Supposed to have 1-5volts while running. There’s a wiring schematic in back of manual. I can find the switch and the wires in it but I have no idea how to follow it from there. I’m stuck again lol. Any help would be great. Thanks

and you are measuring this between black and green wire? Or black and chassis ground of Genset?
What do you measure between red and green wire?

 

[Southernman13]

and you are measuring this between black and green wire? Or black and chassis ground of Genset?
What do you measure between red and green wire?
[/QUOTE I don’t see where I said black and green wire. I measured between the black wire and chassis ground
I think I found where the wires go. This terminal strip is A1/P6.

 

[Southernman13]

I’m sorry I know I’m very confusing and not being able to post the complete schematic is no help either.

 

[Southernman13]

I’m sorry I know I’m very confusing and not being able to post the complete schematic is no help either.

Actually the manual says if it doesn’t have the 1-5 VDC reading to replace it. I’m gonna pull it out and inspect and clean it first

 

[peapvp]

Actually the manual says if it doesn’t have the 1-5 VDC reading to replace it. I’m gonna pull it out and inspect and clean it first

Note:
Black in the wiring diagram is Ground
White is Signal which is 1 to 5 V
Red is Power-supply 12V for sensor

on some generators, the white wire (signal) is actually green

the manual itself, when it states to check for 1 to 5 V on the black wire Plug P7 Pin 3, is wrong.
This is an outdated manual
The signal is on white or green wire Plug P7 Pin 2 => check on this Pin / Wire for 1 to 5V when Genset is running

this reflects the wiring diagram you posted is correct and the written instructions in the manual has a error

you should never get any voltage on the black wire unless the wire is broken and not connected to chassis ground
This is the sensors ground

@Guyfang
This error in written instructions would explain on how some folks have a generator starting and running and think their oil pressure sensor is bad because they are looking for 1 to 5 V on the ground wire of sensor

Again, this is not the sensor cable shield but the actual black ground wire since this sensor needs 12V and ground to operate
The measured signal is putout on white or green wire with a possible voltage range of 1 to 5 V depending on actual oil pressure sensed by sensor

 

[Guyfang]

Yes it would. What TM date and what changes to the TM, are you using?

 

[Southernman13]

Note:
Black in the wiring diagram is Ground
White is Signal which is 1 to 5 V
Red is Power-supply 12V for sensor

on some generators, the white wire (signal) is actually green

the manual itself, when it states to check for 1 to 5 V on the black wire Plug P7 Pin 3, is wrong.
This is an outdated manual
The signal is on white or green wire Plug P7 Pin 2 => check on this Pin / Wire for 1 to 5V when Genset is running

this reflects the wiring diagram you posted is correct and the written instructions in the manual has a error

you should never get any voltage on the black wire unless the wire is broken and not connected to chassis ground
This is the sensors ground

@Guyfang
This error in written instructions would explain on how some folks have a generator starting and running and think their oil pressure sensor is bad because they are looking for 1 to 5 V on the ground wire of sensor

Again, this is not the sensor cable shield but the actual black ground wire since this sensor needs 12V and ground to operate
The measured signal is putout on white or green wire with a possible voltage range of 1 to 5 V depending on actual oil pressure sensed by sensor

well I went and took it out and cleaned it. Nothing to clean really kinda what I thought. On the sensor itself it says it variable voltage supply up to 35 v. My red wire has no volts going to it. I checked on both sides of the plug just in case there was a break in the wire from plug to sensor. I believe this is my issue. I wanted to jumper wire voltage to it just wasn’t sure if I would backfeed and burn up the computer. So maybe I should get 12 volts to the red wire and see if the sensor starts working? Thanks for the reply

 

[Southernman13]

well I went and took it out and cleaned it. Nothing to clean really kinda what I thought. On the sensor itself it says it variable voltage supply up to 35 v. My red wire has no volts going to it. I checked on both sides of the plug just in case there was a break in the wire from plug to sensor. I believe this is my issue. I wanted to jumper wire voltage to it just wasn’t sure if I would backfeed and burn up the computer. So maybe I should get 12 volts to the red wire and see if the sensor starts working? Thanks for the reply

my question is where does it get the 12volts from so I can check to see what the issue is