Picked up 6 MEP-802A gensets and will be documenting making them all runners here

[pclausen]

I have been spraying the outside of S8 with this:



And worked the switch probably over 100 times at this point, but still get those messed up readings.

I guess the cleaner is not getting into the switch itself and I need to take it apart to clean the contacts?

Is there a thread on here of someone taking one of these apart? Guy indicated it was doable, but challenging.

 

[kloppk]

Here are some pictures of the innards of some of the many layers of S8.
Pictures sent to me by someone who tore one apart.


And yes they can fail...

 

[pclausen]

Thanks for those pics Kurt! I can see where I should concentrate my spraying of the contact cleaner. I'm going to keep at that for a bit longer before contemplating tearing one apart. That's a lot of parts per layer!

 

[pclausen]

No luck spraying into the contact openings. So I opted to pull the switch. Here's one side:



Other side:



Close up of 8 in the "closed" position:



And open position:



Check out the rust dust below where I had the switch when just doing a single position 3 to position 1 change:



Pretty sure I'll need to take it apart to determine if it is salvageable or not.

 

[kloppk]

Since you can see the contacts set the switch so 8 is "closed" and then look into cavity by 7 and see if it appears "closed".
If so I'd then check continuity from 7 to 8.
If no continuity, then I'd run a point file or something between the contacts and then recheck continuity.

 

[Guyfang]

There is no way 3 switches can be bad. I have only seen maybe 3 bad switches in all the time I worked on this set. Dirty, funky, yes. All bad? No. So, that leaves only:
1. You not hitting the right places to measure ohms.
2. The S8 switch schedule is wrong.
3. Switch position is wrong when measuring.

But 3 switches bad, all in the same place at the same time? Stop it.

 

[DieselAddict]

Is there any way you can put some cleaner in a small container and soak the switch?

 

[pclausen]

Filing all the contact points did the trick! At first it didn't, but after keeping at it for a good 30 seconds per contact set, I started showing continuity. So I did all 48 contact pairs (46 actually since 19/20 is blank). After doing them all, I tested for continuity in all settings, and everything looks good now.

Sprayed all contact with contact cleaner just for good measure.

Looks like I'll rinse and repeat for the set with low compression when I get that far.

Now to put it all back together again.



At least I didn't tear the entire switch apart!

 

[robertsears1]

I have taken apart 2 switches like that but they are only1/3 the length. Somehow I got one back together and the other still sits in a jar. That will be extremely difficult to reassemble!

 

[kloppk]

Filing all the contact points did the trick! ....

Before your post I tore the roof off my 802 to check if 7 to 8 was closed in 120/240.
It is...


Time to put my roof back on now that the mystery is solved.

 

[pclausen]

Got the switch put back in and wired. I verified I had continuity where expected on TB3.

Fired it up, and what do you know, I'm finally making power! Measured 240V across L1 and L3 and 120V between those two and Neutral on the main output terminals.



None of the gauges work, so that's next, but I'm very glad to finally be making power!

 

[Guyfang]

One step at a time.

 

[pclausen]

Turns out, except for the ammeter, all the gauges in my spare set are shot. And the ammeter shows that the alternator isn't charging the batteries while the set is running, so I'll be swapping that over from the spare set as well.

At least the Frequency Transducer is working as I'm seeing about 0.11 Ma when at 60 Hz and increasing to about twice that at 65 Hz. Also seeing 240 VAC across the terminals on the AC Volt Meter.

Don't know about the load meter yet, since I don't really want to put a load on this until I have the other gauges working, at least the engine ones.

Datcon Oil Pressure Gauge 24V 240-33.5 Ohms 0 - 80 PSI 52mm Black Bezel	101574	$33.36
Datcon Water Temperature Gauge 24V 100-280 degrees F Black Bezel	101582	$33.36
Datcon Fuel Gauge 24V 240-33.5 Ohms 52mm Black Bezel	101584	$33.36
Ideal Frequency Meter 36.1912	NSN 6625-01-038-6869	Unoptanium
Ideal Volt Meter 36.1884	NSN 6625.01.038.6826	Unoptanium

vehiclecontrols.com have a decent deal on the engine gauges, but those large indicators seem to be hard to source, at least I'm not having much luck.

I'll probably steal gauges from one of my working sets just to complete the load testing on this unit, to make sure I'm not in for additional surprises!

 

[nextalcupfan]

I found these on Mouser and they look like they would work, unfortunately they aren't stocked anymore so I'm not sure if you can still get them.

https://www.mouser.com/ProductDetail/Simpson-Electric-Company/08490?qs=sGAEpiMZZMtFJx2zDaGuWEK0jQji%252BSq7wsRnikEqvgM%3D

https://www.mouser.com/ProductDetail/Simpson-Electric-Company/35162?qs=sGAEpiMZZMtUpMOmSPzkH043jT3dqOJH

EDIT:
I just found out the frequency meter won't work with the stock wiring on a 80xx set.
I didn't know the stock gauge used a frequency determining transducer with the stock meter.
The meter I linked says 120v input which tells me its supposed to be hooked directly to 120V AC.
Now it really wouldn't be that hard to either extend the wiring from the transducer or find some other 120V AC source but I just thought I would mention it.

 

[kloppk]

Newark has 4 of the 08490

 

[pclausen]

You guys rock! Picked up the voltmeter from Newark.

 

[kloppk]

Newark has 4 of the 08490

A great tool for finding electronic parts is Octopart.com
Just put in the part number and it will display what distributors carry the part, how many they have in stock and pricing.

 

[nextalcupfan]

I've been thinking about this one myself.

APM-PWR-APO Trumeter | Industrial Automation and Controls | DigiKey Marketplace

Order today, ships today. APM-PWR-APO – Energy Monitor (Power Meter) LCD - Tri Color Characters, Backlight Display Panel Mount from Trumeter. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

Installing it where the Voltmeter goes should work without compromising the original panel info too much (I really don't want to give up the factory %rated current meter)

APM-FREQ-ANO Trumeter | Industrial Automation and Controls | DigiKey Marketplace

Order today, ships today. APM-FREQ-ANO – Frequency Meter LCD - Tri Color Characters, Backlight Display Panel Mount from Trumeter. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

And this for replacing the Frequency Meter.

I checked the cutout dimensions and its basically a square of the hole already in the gauge panel.

They look kinda cheap but not too cheap if you catch my meaning.
You can get them with a green background that kinda matches the theme of the set too, which is nice.

 

[Guyfang]

Learn something new every day! Now, the hard part is remembering it.

 

[pclausen]

Those are very cool looking digital gauges! Might consider those for my "keeper" 803 and 802 sets, depending on how many other failed gauges I have in the other sets I'm fixing up.