MEP-804B Problem Starting

[peapvp]

My bad. I meant S10-1 and S10-2

Yes, and that’s when the voltage on 10-2 collapses from 25V to ~7VDC
either with jumper as you requested or by pushing S10 to crank

 

[Guyfang]

Then the wire from MT4 to S10 could also be bad.

 

[peapvp]

Then the wire from MT4 to S10 could also be bad.

That’s what we are concluding
wire 163, but
Voltage drop happens already on MT4 when S10 is pushed to crank so that points to MT4 and FU1

 

[Guyfang]

OR, the wire from G1 to MT4. Or, the wire from the G1 to the battery. Loose battery clamps. Those places need to be ruled out also.

 

[peapvp]

OR, the wire from G1 to MT4. Or, the wire from the G1 to the battery. Loose battery clamps. Those places need to be ruled out also.

G2, it’s G2 in the drawing and connects through FU1 to MT4(1)
battery comes in on MT4(4) but the MT4 he got in his Genset has only 2 terminals and not 4 as shown in TM wiring diagrams.
That‘s where he stopped troubleshooting as MT4 is right behind the panel shown here in this picture and is a pain to get to

 

[peapvp]

One correction we have to
maKE:
the 25A Fuse FU1 in the Alpha Version becomes CB2 in the Bravo Version
wiring numbers are the same but the letters differ
this is the connections for MT4 in Bravo

also the MT4 has two smaller screws screwing into each main terminal from the side.
so MT4(1) and (2) are one post and (3) and (4) the other post
hard to see in the pictures or in the cubicle because (2) and (3) screws are facing the rear wall of the cubicLe……..

Thats requires some intricate yoga positions to get to those

 

[Rik]

I ran the generator yesterday and I checked the continuity between post on the MT4(1) & MT4(4) and they show continuity when running and a running voltage of 27V. I don't know if this fuse between the two post is good/bad but

 

[Rik]

If you take a short piece of wire, and jump from S10-1 to S10-2 the engine should turn over. And that means S10 is bad. If the engine will not turn over, then the wire from S10 to K2 is bad.

I took S10(1) and S10(2) off and touched them together and nothing as I suspect S10(2) does not have a good connection somewhere

 

[Guyfang]

And if you take a wire and go from the + terminal on the starter to S10-1. Will the set turn over?

 

[Rik]

And if you take a wire and go from the + terminal on the starter to S10-1. Will the set turn over?

This is exactly what I have done and it cranks and fires right up like there's never was a problem.

Until the breaker (FU1) and Shunt (MT4) arrive, I am running the genset in this configuration

 

[Sarid]

this fuse has 25v on both sides of it and continuity so it’s good

hello, my mep 804b doesn't have that fuse. what model is this fuse ? I want to buy this. Thanks

 

[Guyfang]

Sarid,
It would be better if you had your own thread. It will get you more help, and confuse less people in this thread. If you need help, tell me and I will help you start a thread. Also, what fuse are you talking about?

 

[Rik]

hello, my mep 804b doesn't have that fuse. what model is this fuse ? I want to buy this. Thanks

Do you mean the 25amp battery charging system circuit breaker?

 

[Guyfang]

See what I mean?

 

[Rik]

See what I mean?

Exactly, with no given context it's very confusing and difficult to accurately respond to.