MEP 802a Wiring Short

Steel Soldiers is supported by:

fosgittr

New member
18
11
3
Location
Midland, MI
So I have a MEP 802a that I have been rebuilding and was working on getting it started tonight. Turned the main switch to the heaters and a massive short occurred. Burnt up wires 109C from the starter to the K18 relay and 116C from the K18 relay to the heater plugs. Crispy, and lots of smoke. I suppose K18 is probably fried too. Does anyone have any ideas what might have caused this? Do I even need the heater plug circuit for it to operate? Also, wondering where to find out wire size so I can replace the wiring eventually.
 

mciikurzroot

Member
Supporting Vendor
78
82
18
Location
wimberley texas
"Do I even need the heater plug circuit to work" ??
No ! I think I'd just go ahead and skip it now...

Seriously.. The wire size is identified on each individual wire.. EXAMPLE: 165A16 the wire size is told to us by the last 2 numbers, in the example its size 16 if for example it was 165A14 then the wire size is 14 if the wire is marked 165A10 well you get how it works now #10 wire size ... more ? the 165 is a number relating to a specific starting or ending location or item point, some wires extend into double letters after extending thru a-z then if needed the process will be AA - AZ I have never seen a 3 letter string. [yet]
As a set grows in size and accessories then the total number of wires grows pretty big and a bit of sophistication as well. 100 is most often used as the battery negative pathway, 101 is mostly the ground wiring moving on 105 is typically AC neutral ..

In the MEP 800 series MEP really started to get their act together from the earlier days of wire numbering , where as your exposure grows you know by instinct and can move between the sets and generally know from your experience where your going and coming from point/location i speak of, as well what sub set of functions your working within.. as you follow a + or positive supply wire for example as the wire leaves from its initial landing the wire number remains the same [usually, near always] but the letter will change to B to and from the next point/location then change to C while keeping the same leading number and as we already covered ending wire size number.. As a observation, at first it looks a bit overwhelming, but as you expand you working knowledge or experience you will come to see it's really very simple and quick to follow ...
When a + supply wire lands at a fuse or circuit breaker, very likely when it leaves as the supply or load wire to a item it will change into the 200 series numbering scheme. For every example i have cited you can find exceptions, but that's not my point.. Just one more item to add confusion, some times the ink color red or black tells us polarity but that is less and less i see this..
I have a MEP-1080 right now im making some changes for, and while over 275 wires land inside the CIM control box and the leading numbers reach into the 400's, but these sets are 100% digital control including the entire engine.. And IMO have way too many extra features [crap] thus my goal to clean emm back to basic real functions, I'm drifting away here, but will add these John Deere all digital engines run soo smooth and super fuel efficient and environment friendly wet stacking and black smoke are non existent issues..

I forget what Tech manual offers all this insight, but there is a madness to it...

ok end of rant.. best of luck: mac/mc
 

mciikurzroot

Member
Supporting Vendor
78
82
18
Location
wimberley texas
I didn't share that long answer to scare cause any trepidation for you at all, my apology if i did, and the 300 and 400 series wire numbers from my experience seems directly related to or if the set uses CANbus and/or RS-485 control/diagnostic ability .. mac/mc
 
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks