Mep 803 alternator test?

[Waterhouse]

Way back whe I bought my 803, I was reading threads on here and I came across a thread that had a few simple tests for the DC part of the generator. I remember thinking that’s good to know, but I was working getting the motor running at the time. Now that I getting somewhere on that front, I would like to run the tests to my non charging alternator. i could have sworn there was a stick, but I can’t find anything in my searches. I’m sure it’s right in front of my nose. Could someone point me to it?

 

[2Pbfeet]

Either of these?

MEP 803A testing alternator output

Hi everyone. Everything is pretty much good on my 803 at this point. Although the batteries I have in it are really old, the other day I went to crank it and they were dead. I charged them and ran it a couple times just fine and this morning it was dead again. I think its just the batteries. I...

www.steelsoldiers.com

MEP 803A is ALIVE!

It took some time to get things going but I finally got the genset running. Not that it had any problems. I had problems getting the fuel/water filter off. What a tremendous pain in the butt. I don't think anything has ever got me so angry. I read on here the problems some of you have had...

www.steelsoldiers.com

or this one?

mep 803a stopped on its own, wont turn over via main switch, has battery power

Good info here on failed alternator diodes: https://www.steelsoldiers.com/showthread.php?143877-MEP-802a-Low-Alternator-Voltage-Output May help with your rebuild. MEP802A and 803A use the same alternator.

www.steelsoldiers.com

 

[Waterhouse]

Hey guys back again,

I saw something about the “FU-1” could stop the unit from charging. Didn’t even know what that was, but when I opened the front panel there was a spot labeled FU-1. And of course it was just a hole with dirt in it. I washed out the dirt and it looks like a socket for a fuse or a light bulb. Anybody got a source to complete this. What exactly goes in there? Can I just short the wires there for a test?

 

[Ray70]

That's your problem! That is the fuse holder for the alternator, supposed to be a 30A glass tube fuse in there, your typical 1 1/4" automotive style.
I bet @Light in the Dark or @kloppk have a source available for a new holder, unless you see a gray cap with 2 little metal tabs sticking out rolling around inside the control panel?? Quite often the caps are sitting in the machine somewhere if you got it from the auction.

 

[kloppk]

I might have one. Would need to look through my my parts stash to see if I have one.

 

[Waterhouse]

That would be an easy fix. I did get mine from an auction. I guess I need to search it. Mine looks like this right now. (not mine)



Is it possible to find at an auto parts store?

 

[2Pbfeet]

Marine stores often stock them. I'd try that first over an auto store. They will probably have the glass fuse that you need as well.

All the best,

2Pbfeet

 

[Light in the Dark]

https://www.mouser.com/ProductDetail/Bussmann-Eaton/BK-ABC-30-R?qs=St27ATL478s0HesTffljHg%3D%3D&countrycode=US&currencycode=USD

https://www.mouser.com/ProductDetail/Bussmann-Eaton/BK-HKP-R?qs=jGANiKWBgcgdglko7ruoNg%3D%3D&countrycode=US&currencycode=USD

 

[Light in the Dark]

You can choose to desolder whats there and use all new... or just use a black cap on a grey housing (which I have done countless times) and move on with life

 

[kloppk]

@Waterhouse You're in luck. I have a complete fuse holder with fuse available.
Sending PM..

 

[Waterhouse]

@Waterhouse You're in luck. I have a complete fuse holder with fuse available.
Sending PM..

View attachment 923710

Where do I send money?

Edit, just saw the PM thing.

 

[Waterhouse]

I can be really stupid some times. I have a working Mep802 right outside my shop. I looked and it has the same FU1. I pulled it and plugged it in the 803 and it charges. I still need to get one for it, but at least I know it works.

 

[Ray70]

I have a working Mep802 right outside my shop. I looked and it has the same FU1. I pulled it and plugged it in the 803 and it charges.

Precisely why everyone should keep a "Spare" generator on hand! It is soooo... much easier to diagnose issues and swap parts to verify!
Green Machine Fever at it's finest!

 

[Guyfang]

Waterhouse wrote:
I can be really stupid some times. I have a working Mep802 right outside my shop. I looked and it has the same FU1. I pulled it and plugged it in the 803 and it charges. I still need to get one for it, but at least I know it works.

About 98% of the parts fit, between the MEP-802 and the MEP-803.


This is straight out of the -24 TM, troubleshooting.
19. BATTERY CHARGE AMMETER SHOWS NO CHARGE WHEN BATTERIES ARE LOW OR DISCHARGED.
Step 1. Check for broken or loose fan belt, paragraph 2-75-1.
a. If fan belt is not broken and tension is correct, do Step 2.
b. If worn or broken, replace fan belt, paragraph 2-75. If loose, adjust fan belt, paragraph 2-75-4.
Step 2. Check for defective BATTERY CHARGER FUSE (FU1), paragraph 2-25-2.

Not being mean here, but often spending a little time in the TM saves you lots of time and money later. Anytime I am getting ready to do some troubleshooting, I first drag out the book. Its way smarter than me.

 

[Waterhouse]

Waterhouse wrote:
I can be really stupid some times. I have a working Mep802 right outside my shop. I looked and it has the same FU1. I pulled it and plugged it in the 803 and it charges. I still need to get one for it, but at least I know it works.

About 98% of the parts fit, between the MEP-802 and the MEP-803.


This is straight out of the -24 TM, troubleshooting.
19. BATTERY CHARGE AMMETER SHOWS NO CHARGE WHEN BATTERIES ARE LOW OR DISCHARGED.
Step 1. Check for broken or loose fan belt, paragraph 2-75-1.
a. If fan belt is not broken and tension is correct, do Step 2.
b. If worn or broken, replace fan belt, paragraph 2-75. If loose, adjust fan belt, paragraph 2-75-4.
Step 2. Check for defective BATTERY CHARGER FUSE (FU1), paragraph 2-25-2.

Not being mean here, but often spending a little time in the TM saves you lots of time and money later. Anytime I am getting ready to do some troubleshooting, I first drag out the book. Its way smarter than me.

I have a terrible time finding anything in there. I need to get a printed copy. I have printed some pages.

 

[Light in the Dark]

I have a terrible time finding anything in there. I need to get a printed copy. I have printed some pages.

There are multiple variations of the TMs, with different trailing numbers (-10, -24, -24p, etc). They all house different pertinent info.

Happy to explain the differences if you aren't aware. Won't repeat what you already know, if you do.

 

[Waterhouse]

Today I load tested the generator to 75% and it worked fine. The temp guage went to about 210, but the air coming from the rad didn’t feel very hot. When I pointed a temp gun at the rad, it was only 170. Does that sound right? I had the door on the one side open because I had batteries outside. Would the door open cause it to run hotter?

Does anybody have a Source for the brass nuts on the main output terminals? I need all four. Good thing I had the 802 on hand for testing.

 

[FarmingSmallKubota]

A parts wanted ad would be better. that way you could put all the parts you need in it at one time. Seems you keep finding missing things on this unit

 

[Guyfang]

The machine is supposed to run and cool itself with all doors shut.
Start a parts wanted thread. For some parts its a good idea to provide part numbers and NSN's.
Said part numbers and NSN's can also help you find parts on line.

 

[Ray70]

Also, don't rely on the accuracy of the machine's temp gage. Typically they have a 180* thermostat but the gage tends to read 20+* hotter than the machine really is.