Electronic governor control for MEP 804B

[Antonio Pena]

The quad fuse mod is to protect the A1 volt regulator. It has a fuse in it to keep the A1 from over volting.

Quad fuse is installed and provides power to A1, I did a test for the AC voltage regulator per TM 9-6115-643-24 ( 4-1.1 ) h, has between 4 and 12 VDC J, terminal 10 and 11 of AC voltage regulator does not indicate 210 to 280 VAC i, does read 3000 ohms. Statement m is got me confused (easy to do) " If steps H, j, and i are as indicated above AC voltage regulator is defective and must be replaced" I'M lost not a clue in how to proceed and frustrated! Also I checked ohm reading on exciter field leads and came up with 34 ohms range is between 28.6 and 38. 7 . I've got way to much money and time invested on this iron sled! That started out with the motor and turned out to be the fuel pump internally out of timing that I had bench tested for repairs. Aggravation is setting in any HELP would be greatly APPRECIATED THANKS

 

[Guyfang]

Quad fuse is installed and provides power to A1, (The fuse is supposed to protect the Quad winding. The voltage goes from the A1, TO the Quad winding. On startup, what voltage did you measure on A1 terminals 5&6 and 7&8. The voltage should be DC voltage. Measure 7&8 first, on startup. That's the Quad winding's. Then let the S1 go, and measure 5&6.) I did a test for the AC voltage regulator per TM 9-6115-643-24 ( 4-1.1 ) h, has between 4 and 12 VDC J, terminal 10 and 11 of AC voltage regulator does not indicate 210 to 280 VAC i, does read 3000 ohms. Statement m is got me confused (easy to do) " If steps H, j, and i are as indicated above AC voltage regulator is defective and must be replaced" I'M lost not a clue in how to proceed and frustrated! Also I checked ohm reading on exciter field leads and came up with 34 ohms range is between 28.6 and 38. 7 . I've got way to much money and time invested on this iron sled! That started out with the motor and turned out to be the fuel pump internally out of timing that I had bench tested for repairs. Aggravation is setting in any HELP would be greatly APPRECIATED THANKS

 

[Antonio Pena]

Excuse me for being so ignorant to the forums. I checked A1 terminal 7 & 8 at startup read 1 volt, terminal 5 & 6 = 5v with motor running. please advice
Thank You

 

[Guyfang]

You are not ignorant. You just need more time.

On startup, you can hold the S1 as long as you want. So, 1 volt on pins 7&8? Thats not enough. Is your S1 made all of plastic? Or is it metal/plastic?

 

[kloppk]

You are not ignorant. You just need more time.

On startup, you can hold the S1 as long as you want. So, 1 volt on pins 7&8? Thats not enough. Is your S1 made all of plastic? Or is it metal/plastic?

I believe he should be looking at pins 1 & 3 on the VR for the Flashing voltage.
7 & 8 would be for the 802/803

 

[Guyfang]

OH crap! I was on the wrong wire diagram.

 

[Guyfang]

We should also be able to read at the P3, canon plug, pins F and J. F being the red lead, J being the black lead. You should get between 0-60 volts DC. Try that.

 

[Guyfang]

Thanks Kurt! been looking at wire diagrams all day with someone else.

 

[Antonio Pena]

Thanks Kurt! been looking at wire diagrams all day with someone else.

Thanks Kurt! been looking at wire diagrams all day with someone else.

Terminal 1 & 3 at start up is 0 volt on VR

 

[Antonio Pena]

No voltage at startup between F and J

 

[Antonio Pena]

You are not ignorant. You just need more time.

On startup, you can hold the S1 as long as you want. So, 1 volt on pins 7&8? Thats not enough. Is your S1 made all of plastic? Or is it metal/plastic?

Plastic.

 

[kloppk]

Looks like Guyfang is away from his computer so I'll give you some suggestions
No DC voltage at VR terminals 1 & 3 with S1 held in the START position indicates there is a problem with the Flashing circuit in the set.
I'd suggest the following to start and find out why.

Try the following tests in order. Stop when you no longer see DC voltage.
Connect your meters negative lead to ground stud above all the relays inside the control cube.
Set the meter to volts DC
1) Measure the DC voltage at S1 terminal 7 with S1 held in the START position. You should read about 24 volts DC.
2) Measure the DC voltage at CR4 terminal 1 and terminal 2 with S1 held in the START position. You should read about 24 volts DC.
(CR4 is located on the back wall of the control cube on the far left.)
3) Measure the DC voltage at R14 terminal 1 with S1 held in the START position. You should read about 24 volts DC.
(R14 is located on the back wall of the control cube on the far left.)
4) Measure the DC voltage at R14 terminal 2 with S1 held in the START position. You should read between ~5 and ~11 volts DC.
5) Measure the DC voltage at CR2 terminal 1 with S1 held in the START position. You should read between ~5 and ~11 volts DC.
(CR2 is located on the back wall of the control cube on the far left.)
6) Measure the DC voltage at CR2 terminal 2 with S1 held in the START position. You should read between ~5 and ~10 volts DC.

The plastic versions of S1 are failure prone.

 

[Antonio Pena]

Looks like Guyfang is away from his computer so I'll give you some suggestions
No DC voltage at VR terminals 1 & 3 with S1 held in the START position indicates there is a problem with the Flashing circuit in the set.
I'd suggest the following to start and find out why.

Try the following tests in order. Stop when you no longer see DC voltage.
Connect your meters negative lead to ground stud above all the relays inside the control cube.
Set the meter to volts DC
1) Measure the DC voltage at S1 terminal 7 with S1 held in the START position. You should read about 24 volts DC.
2) Measure the DC voltage at CR4 terminal 1 and terminal 2 with S1 held in the START position. You should read about 24 volts DC.
(CR4 is located on the back wall of the control cube on the far left.)
3) Measure the DC voltage at R14 terminal 1 with S1 held in the START position. You should read about 24 volts DC.
(R14 is located on the back wall of the control cube on the far left.)
4) Measure the DC voltage at R14 terminal 2 with S1 held in the START position. You should read between ~5 and ~11 volts DC.
5) Measure the DC voltage at CR2 terminal 1 with S1 held in the START position. You should read between ~5 and ~11 volts DC.
(CR2 is located on the back wall of the control cube on the far left.)
6) Measure the DC voltage at CR2 terminal 2 with S1 held in the START position. You should read between ~5 and ~10 volts DC.

The plastic versions of S1 are failure prone.

Thank you, I'll go thru your steps and keep you guys posted

 

[Guyfang]

Thanks Kurt. I have a handful with two grand kids, to sons, and two chattering females and this computer is in the dining room. They have all at last gone someplace else. Thats the way I was looking. S1-7 has to have voltage, and then on through the path to the F1 & F2.

 

[Antonio Pena]

That was easy enough CR4 T1 & T2 no voltage what size diode is this? I'll have to replace it, I do have a variety of diodes I'm not to good with the solder gun maybe I can crimp it? Thank you for helping me out that's a strat. Guy I know what it's like with the little one's. Were in FL and the rain keeps messing with me! THANKS again for helping out I'll be in tuch.

 

[kloppk]

If CR4 Terminal 1 doesn't have any voltage the problem is not CR4. Problem is the 24 volts DC isn't getting from S1-7 to CR4-1 or S1-7 doesn't have 24 volts DC on it when S1 in held in the start position.
Did you verify that S1-7 has 24 volts DC on it with S1 held in the START position?

 

[kloppk]

Here is how the 24 volts gets from S1-7 to to CR4-1.
S1-7 -------------wire # 190a ----------------TB6-8--------------wire # 190C-----------------CR4-1

 

[Antonio Pena]

If CR4 Terminal 1 doesn't have any voltage the problem is not CR4. Problem is the 24 volts DC isn't getting from S1-7 to CR4-1 or S1-7 doesn't have 24 volts DC on it when S1 in held in the start position.
Did you verify that S1-7 has 24 volts DC on it with S1 held in the START position?

S1-7 was 24V

 

[kloppk]

OK now see if there is 24 volts DC at TB6-8 with S1 in the START position.

Verify TB6-8 has 3 wires to it. Two on one terminal and one on the other.

 

[Antonio Pena]

I'm screwed up I checked CR4 T1 to T2 that's why I don't have voltage just tested it again and it has 24V CR4 T1 to ground and T2 to ground. I'll keep going and give you a heads up Thanks