Electronic governor control for MEP 804B

[Antonio Pena]

Yes

 

[kloppk]

With S1 in START measure the DC voltage at
A5-18
A5-19
A5-20

 

[Antonio Pena]

Now check K15 Terminal A then Terminal B with S1 held in start.
A should be ~24 volts and B should be ~0 volts.

 

[Antonio Pena]

Stupid question how do I keep from starting the engine to do the tests?

 

[kloppk]

All these tests must be done with the engine running.
The MPU has to detect the engine is up to RPM before the field flash circuit can operate.

 

[Antonio Pena]

Okay thanks

 

[Antonio Pena]

24 V on A B - 0

Okay thanks

V

 

[Antonio Pena]

24 volts on A, 0 volts on B

 

[kloppk]

OK now do these checks...
With S1 in START measure the DC voltage at
A5-18
A5-19
A5-20

 

[Antonio Pena]

With S1 in START measure the DC voltage at
A5-18
A5-19
A5-20

With S1 in START measure the DC voltage at
A5-18
A5-19
A5-20

A5-18, 0 volts
A5 - 19, 24 volts
A5-20, 24 volts

 

[Antonio Pena]

A5-18 0 volts
A5-19 24 volts
A5-20 24 volts

 

[kloppk]

OK
Now with S1 in START measure the DC voltage at
K15-7
K15-4

Also see if you see the K15 relay open and close as you move S1 from RUN to START and back to RUN while it's running.

 

[Antonio Pena]

OK
Now with S1 in START measure the DC voltage at
K15-7
K15-4

Also see if you see the K15 relay open and close as you move S1 from RUN to START and back to RUN while it's running.

K15-7 24 V
K15-4, no voltage on start
The contact dose open and close with S1 start

 

[Antonio Pena]

It’s a good thing that with the unit running I can switch to start without running the starter

 

[kloppk]

Based on your measurements it indicates K15 is the problem.
Odd because relays rarely fail.

What should be happening is K15-7 gets 24 volts when the engine is up to speed.
When you move S1 to START K15 closes and should pass the 24 volts on terminal 7 to terminal 4.
However you are measuring 0 volts on K15 terminal 4.

 

[kloppk]

It’s a good thing that with the unit running I can switch to start without running the starter

That part of the job of the MPU. When the engine is up to speed and the MPU detects the RPM and causes the starter to be disabled. It also enables flashing at the same time.

 

[Guyfang]

I just woke up, and started reading this before I go back to bed. Swap K 14 and K15. See if your symptoms change.

 

[Antonio Pena]

Based on your measurements it indicates K15 is the problem.
Odd because relays rarely fail.

What should be happening is K15-7 gets 24 volts when the engine is up to speed.
When you move S1 to START K15 closes and should pass the 24 volts on terminal 7 to terminal 4.
However you are measuring 0 volts on K15 terminal 4.

I just woke up, and started reading this before I go back to bed. Swap K 14 and K15. See if your symptoms change.

I did swap out the relays K14 with K15 same problem although when I held S1 in start I do get 120 volt to the convinces outlet

 

[Antonio Pena]

I swapped out relays K-15 with K-14 same problem persiste although when I hold S-1 in the start position I do get 120 volt to the convinces outlet

 

[kloppk]

Did you have power at the convenience outlet before you swapped the relays with S1 in START?

With the relays swapped do you get power to the outlet with S1 in START and do you lose power there when you release S1 back to run?