MEP-803A voltage quit

[RHRocket]

Good afternoon I have mep-803a installed new motor and it ran for 3 hrs absolutely no problems and then out of nowhere stopped producing voltage. I have checked alot of things mentioned here and my quad field only register .9 and now I just found that stator is reisters when I check stator leads to housing

 

[Guyfang]

Have you down loaded the TM's and read the troubleshooting sections? Do the voltages mesured look like those in the below download?

 

[RHRocket]

No they don't. I only had like 11 volts instead of 117 and I had nowhere close to 67

 

[RHRocket]

I have downloaded and been doing bunch of testing. After new engine installed worked great for 3 hours and then no power but engine is running good

 

[kloppk]

Try this...
Start the set and with S1 held in the START position and repeat the voltage measurements listed in the PDF that Guy posted.
Post up the AC and DC voltages you measure across the pairs of terminals.

 

[RHRocket]

Try this...
Start the set and with S1 held in the START position and repeat the voltage measurements listed in the PDF that Guy posted.
Post up the AC and DC voltages you measure across the pairs of terminals.

Ok so rechecked these with s1 held to start. 1-2 is .08 vac, 3-4 doesn't measure, 5-6 23.3 vdc, and 7-8 doesn't read.

 

[kloppk]

..., 5-6 23.3 vdc...

This tell me that there is an open circuit in the wiring to the Exciter or the Exciter has developed an open in it.

Label wires on terminals 5 & 6 on the VR and then remove them from the Voltage Regulator (VR).
Use your meter to measure the resistance between the two wires just removed from the VR.
It should measure ~10 to 15 ohms.
If you get an open resistance reading there then remove P5 from the J5 connector. Will need to open the door for storing the aux fuel hose to get to it. To remove P5 you'll need to rotate the locking collar before removing P5 from J5.
Examine the contacts for corrosion. If OK measure the resistance between pins 1 & 2 of P5. It should measure ~10 to 15 ohms.
If not then examine the wires running from P5 all the way to the gen head and where they enter the gen head. Occasionally the wires break or get chewed thru by rodents there where they enter the gen head. Have seen it a few times.

 

[RHRocket]

Awesome I will check it tomorrow. I am traveling today to look at a couple jobs.

Thank u

 

[jamawieb]

I just had a unit that I was load testing with 279 hours. Stop producing and found a wire on the reconnection switch fired. I 99% sure it fried the windings

 

[DieselAddict]

I just had a unit that I was load testing with 279 hours. Stop producing and found a wire on the reconnection switch fired. I 99% sure it fried the windings

Loose connection?

 

[RHRocket]

This tell me that there is an open circuit in the wiring to the Exciter or the Exciter has developed an open in it.

Label wires on terminals 5 & 6 on the VR and then remove them from the Voltage Regulator (VR).
Use your meter to measure the resistance between the two wires just removed from the VR.
It should measure ~10 to 15 ohms.
If you get an open resistance reading there then remove P5 from the J5 connector. Will need to open the door for storing the aux fuel hose to get to it. To remove P5 you'll need to rotate the locking collar before removing P5 from J5.
Examine the contacts for corrosion. If OK measure the resistance between pins 1 & 2 of P5. It should measure ~10 to 15 ohms.
If not then examine the wires running from P5 all the way to the gen head and where they enter the gen head. Occasionally the wires break or get chewed thru by rodents there where they enter the gen head. Have seen it a few times.

What is this part?

 

[RHRocket]

What is this part?

 

[kloppk]

In the -24 it's referred to as Connector Board AS.
Appears to be the connection point where the Exciter wires get hooked to and where the F1 and F2 wires from the VR get hooked to. I suspect you found 1 or more of those 4 wires not connected to it.
Just my guess based on its markings.
People that have dug into the gen heads would know for sure.

 

[RHRocket]

In the -24 it's referred to as Connector Board AS.
Appears to be the connection point where the Exciter wires get hooked to and where the F1 and F2 wires from the VR get hooked to. I suspect you found 1 or more of those 4 wires not connected to it.
Just my guess based on its markings.
People that have dug into the gen heads would know for sure.

They were hooked up but if I put ohms meter on the connector plug and check ohms it's not consistent. If I wiggled the wires at this connector board it would get connection. I tightened the connections but still wasn't right. There is resistance between the terminals on this connection board. Kinda wondering if this board can go bad?? Just curious

 

[kloppk]

It simply a non conductive board with two dual spade connectors riveted on it.
The only thing that could go bad is if the metal tabs of the connectors on it get corroded leading to poor or no contact.

 

[Ray70]

Kurt is correct, it's just a connection point that allows you to separate the connections to remove the end of the generator and the field stator.
I would just clean as best you can, maybe pinch the female end closed a little more for a tighter fit and check continuity.

 

[RHRocket]

Kurt is correct, it's just a connection point that allows you to separate the connections to remove the end of the generator and the field stator.
I would just clean as best you can, maybe pinch the female end closed a little more for a tighter fit and check continuity.

Yeah I cleaned the contacts and all the connections and then started still nothing just now checked the exciter field again I have absolutely nothing on ohms now on the Exciter. Anybody have Exciter p/n or have spare laying around

 

[Guyfang]

Take the time to look. Open up the main gen and check the circuit from the board to exciter. I have seen pinched wires, I have seen chewed up wires. I have seen bad connections. Take the time before spending money.

 

[Ray70]

If you find an issue with the exciter stator I think I have a couple spares. if the problem ends up being in the rotor I will have to look, not sure if I have any to spare.