MEP-002A Multiple Issues...

[n5yzv]

Hi All. I have a few things going on. A few leaks, batteries not charging, control panel breaker popping when priming...but those have become secondary to my latest find.
I think my main switch (S1) is bad. First, the physical issue is that it seems to get bound up from time to time. The only way I can free it up is to force it back an forth.
On the electrical side (pull out your electrical schematic):

TB4-10 --> S1-27 :
I am thinking I should have continuity between S1-27 and S1-13/14 (this goes to the primary pumps). I am checking this with an ohm meter, and I don't. The only way I have continuity is if I move the selector over to Start (which I think is S1-26).

The current state of the panel is not functioning at all. I do have 24v going to K2-A1, but nothing to the other side of the relay at any point.

Prior to this, the control panel breaker was popping when I would set to Prime/Aux Run. I had to disconnect the two primary fuel pumps to keep this from happening. I was getting 24V to the pump leads before the dead panel issue (above, suspecting S1).

Prior to this, (yeah, keeps going) I had it running! Ran great. But the batteries were not charging. I consulted with a friend who noted to pull the positive lead from the battery while it was running. If it keeps running, it is just the battery charger inducer (I think that was it). If it dies, it is the primary 24v inducer (once again, unsure of the term).

It did in fact die. When replacing the power cable, It developed the control panel breaker popping issue.

Prior to this, just one more I promise, the Hz gauge was incorrectly reporting the cycles. I verified this with a clamp on meter.

Any help would be very appreciated.

Mark

 

[Crawdaddy]

Sad to say this, but your "test" of pulling the battery cable while running may have cooked some of the control electronics. These gensets can't handle that.

 

[n5yzv]

Yeah, that is what it seems. I did manage to have it running (with no battery charging) for .4 hours before this.
I have a bad feeling I am looking at the replacement of the A2 (VR ASSY GEN - does this stand for Voltage Regulation Assembly?) or CR2 diode.

How would you recommend testing for battery charging issue?

 

[AceHigh]

If it is near grid power don't worry about the battery charging. Get a charger/monitor or two. When running you can plug them into the convenience outlet.

 

[n5yzv]

yeah, that was a consideration...if I can ever get it running again. I didi find the switch testing procedure, so I'll test it and a few other things later today.

 

[Keith_J]

S1 term 27 is contacted to terms 11-13-15-25-28 when S1 is in position 5 which is start. Have you checked the battery charging fuse?

 

[n5yzv]

yeah, in fact, that was the first think I checked, and did replace the fuse.

I have a bit more new info after some testing:

1. I did try to test the switch, got a bit frustrated, as some would test others did not. So i am not sure on this as I am not 100% sure it wasn't the tester (i.e.: me)

2. I went through the procedure to test A1 and K2 & K3 as noted in the TM on Change 7, Page 4-42.1, chapter 11. I had the battery disconnected, and the two leads on each K2 & K3 disconnected (the upper & lower on each as I was unsure which as A1 & A2). I am unsure if I had CB2 open or not. Anyway, on A1, I should have gotten some sort of resistance between A1-5 & A1-6, and A1-7 & A1-8. I did not. None at all.
I reconnected A1-5,6,7,8, connected the battery cable, and tested K3 (start) and it did show continuity. The second part of this test was to test A1-3 & 4 which also showed continuity. I then tested K2 like K3, but using pre-heat. Nothing. Dead open.

Funny enough, with the battery connected again, I can activate the starter and try to crank the engine (did about 2 - 3 seconds).
In the Prime/Aux Run or the Prime/Rn positions, I have no voltage going to the pumps.

Now, that being said, this all could be caused by a bad switch (S1).

In the TM, Change9, 4-42, Table 4-3 it shows the "Master Switch Continuity Check" Table.
PreHeat 11-15
Off None
Run Aux Fuel 11-13-17
Run 11-13
Start 11-13-15 25-27-28

On fuel note, can I test each fuel pump by connecting it directly to 24v to verify?

When it is a bit cooler out (tonight/tomorrow am) I will go back out and test the switch again. So, at this point I am guessing the possibilities are:
1. Bad switch
2. Bad A1 Diodes
3. Bad PreHeat Relay
4. Bad A2 (cringe!)

Sound like I am on track?

 

[Keith_J]

Yes, you are on the right track. Fuel pumps should flow through the injection pump and back to the tank. Take the cap off and listen. Be careful, a shorted coil in a pump could draw considerable current. Check wiring before to eliminate short circuits.

 

[n5yzv]

I would be shocked if all 3 of my pumps are bad, since I had all 3 working just a day ago. But, once again, if the switch is not passing current, then the pumps won't happen at all. For that matter, the diode (A1) may be fine if the switch is borked.
Anybody know if I can disassemble the switch, clean up and put it back together...and actually have it work?

 

[Keith_J]

I don't know how handy you are but you should be able to fix it. Unless it is badly corroded/broken. I've fixed the ammeter and fuel tank gauge on my 002a even though these are sealed. The frequency meter is beyond repair, all damaged by water.

If you do attempt, do it in an empty room and take pictures of each step. Bag and tag. Never trust numbers on the wires, always trace and verify. Some wires may be replaced without numbering.

 

[n5yzv]

Handy? Heh, I am the kind of person that thinks if another person can do it, so can I....most of the time.

I just got done testing the switch (S1). Everything having to do with PreHeat and the pumps are bad (11,13,15,17). Everything else is fine (25,27,28 I think). So I have labeled everything, color marked each and taken pictures so I don't screw it up. I was able to remove the knob which I hear can be a bastard...but the nut holding the switch into place is badly rusted. I may not be able to remove it. I have lubed it down with a rust remover/lube. Otherwise, I'll have to get creative on cutting it out.

I hope to test the diode (A1) manually tomorrow am, by manually shorting out the correct leads. Needless to say, there will be great care when it comes to testing the pre-heat relay (K2) as the starter relay (K3) has already tested fine.

Thanks for the responses. I have enjoyed learning what I have thus far. I hate having anything that I depend on without knowing how to at least start fixing it.

 

[n5yzv]

A bit of an update:

I have verified the switch is bad and I have likely 1 good pump. The other two are questionable. When applying 24V to the first, it tries to weld my jumper to the battery. The second makes a sound, but much quieter than the Aux pump, which seems noisy enough to be ok. I have not cleaned any of the 3. So I am hoping the second one is just dirty. The shorted one...well...dunno.

I plan to manually test the diode (A1) today/tomorrow. One concern I have is with the AC Reconnect Switch (next to the breaker by the convince outlet). The diagram has 3 selections. West, North and East (i.e.: left, up, right). My switch rests on East. It is spring loaded to North turning counter clockwise. When I release, it returns to East. There are no stops, or any kind of hesitation in the movement. Is this right? If so, how the **** does it work?

Thanks to all!

Mark

 

[mitchdaly]

new MEP003A - help

I picked up an MEP003A with 1900 hours on it last week at Ft. Meade, MD. Unit appears in good condition, but the crew doing the mothballing went overboard. They removed all filters but the air filter. Now I need to find a fuel strainer element. The other filters have already been bought. Any ideas on a source? I've got a John Deere R that has a similar setup (strainer and 2 filters) and it appears to be the same. Would another element like the JD one work? Any help to this new member will sure be appreciated.

 

[mitchdaly]

apologies

I posted my earlier msg by adding onto this thread because I couldn't find out how to start a new thread. I since figured it out and extend my apologies for jumping in. I did figure out that the strainer on my John Deere R is not the same type.

 

[n5yzv]

I would think that as long as the strainer element fits in the can, and seals to the top, it doesn't matter. In fact, the larger surface area the better. Not too long though, so it won't be sitting in the gunk in the bottom of the bowl.

 

[Keith_J]

If the strainer fits, it will work. Remember, each fuel pump also has a strainer. Those are the first to clog and are much smaller.

NAPA sells the correct filter and two smaller gaskets (hard fiber for the bolt outside, rubber for inside) but the shell sealing ring won't work. A 4-1/2" OD o-ring in 1/8" section profile works fine and will not twist. Likewise for the fuel filters. Make sure it is Buna-N or Viton. Viton is a bit better for the oil due to temperature resistance but Buna will work.

Regarding the pumps, it is possible they have shorted to ground from rust. You only need one to get the genset operational.

 

[n5yzv]

Well, I have it up and running again. I got the replacement switch installed (S1) and the diodes replaced on A1. Funny enough, I discovered after I already had them chopped out, that my meter was not testing them correctly. I bought a good meter that had a diode test setting and re-tested. So the replacements are in place. I fired it up, ran ok, but seemed to be starving of fuel. Knowing I had a bad pump, I ran the fuel just through one which took care of the issue. I tested my voltages on the DC side of the unit. On the DC output side of the rectifier, I was getting 26.8V DC. On the AC side I got 36V AC. So after talking to a few mechanics, the general feeling is that the batteries should charge just fine with the 1.5v to 2.5v increase and to keep an eye on it. Nevertheless I'll get a AC charger just in case.
I ran it for about an hour and a half. It all ran fine, minimal load. So engine wise, I think things are coming along.
My next things to do are:
1. Replace fuel lines (leaking a bit)
2. Connect a tractor muffler (need to turn up so it won't blow down into the ASK when installed, as there was no shield in the ASK)
3. Install some sort of Air Cleaner Riser (mine has just a hole, no cover)
4. Address my transfer select switch (dosen't turn correctly)
5. Fix panel lights (not that it is a big deal)
6. Address load meter (mine is bouncing around while in use)
7. Get it out of my garage!! It stinks!
8. Test it for 48 hours under some sort of load. I think I'll connect my pool pump up to it and have it run for the entire time.

Thanks for any comments!

Mark