g741.org

Hi Guys,

Ok.....I got my ignition filter and the thick wire cable that connects to the filter on the driver's side of the truck (I assume this goes to the distributor, but it's too dark outside to go take a look). Now what I need to know is where does the wiring that connects to the other side of the filter go to? In the pics I have it tucks into the firewall behind the air cleaner and is a much thinner wire (see pic below circled in red) than the thick cable coming into the filter on the driver's side. I'm trying to figure out if that thinner wire is still in the truck somewhere, so if I knew where it went to I could start there and back track. Is it part of the dash harness?

thanks,
bob

Well, here is your issue. If you look at the ORD 9 in section 0613 under chassis harnesses, you will note that there are several part numbers referencing the front main. Early on, the harness had two plugs for the master light switch. Bendix version. This harness also incorporated the ignition filter I sent you. #12 on the early versions exited the right side of the cab to connect to this filter. Later on, when they changed the master light switch and discontinued the use of this filter because they then incorporated it in the distributor itself, the #12 wire was re-routed out the left side of the cab and had a junction point just above the distributor. Most trucks when they went in for Depot rebuild, were rid of the early stuff and had the latest superseded parts installed. So, your truck may be early, maybe not. You have to check the serial number against the ORD 9 and these early features to see if your truck really should have them, or, if it is really a later truck that should not. The ORD 9 will give you the "used thru" serial number to decipher this out.
John

John,

Great info. Thanks! Seems this is a bit more complicated than I thought. So ORD 9....here I come!

regards.
bob

Hi John,

Thanks again for your reply. I read what you wrote, looked at ORD 9.....and hope you can give me just a bit more clarification. First let's see if I'm understanding what you wrote......I think what you said was that when the truck was originally made it came with the wiring harnesses listed in ORD 9 for my particular serial number. That SN is 80026562, and it was delivered in April 1952. So I go to ORD 9 and I find out my truck should have the following front harness;

Main Body - G741-8328072, CC-1391394 (used on vehicle serial number 80025705 thru 80037412)

So far so good. But under the description of the Main Body Harness it says "Wiring, body (also specify (1) CABLE assy CC-1501412) and then lists the serial number range. So I checked on what exactly cable CC-1501412 is and it's description says "CABLE, body wiring harness to ignition distributor, assy" and it then lists the serial numbers.

Now I'm not sure (since there are no pics) if the above described cable has anything to do with the ignition filter on the firewall or not because it doesn't mention anything about a filter. So that's my first problem....I know the correct part numbers for the harness I need, but I don't know how that tells me anything about the firewall ignition filter being used or not.

My second problem is I'm not sure I understand what you meant when you said "Most trucks when they went in for Depot rebuild, were rid of the early stuff and had the latest superseded parts installed." So are you saying that if my truck had the ignition filter on the firewall and the associated body harness..... that they would have removed those items at the Depot rebuild and replaced them with the whatever harness was currently being installed in the new trucks? Meaning if my truck was made in April of 52 and had the firewall ignition filter (and associated body harness) and it went thru a Depot rebuild, say in 1958, it would have had it's harness and filter yanked out and replaced with the harness identified for an M37 made in 1958? Or am I reading you wrong? If I'm getting that right.......how would I know if my truck went thru a Depot rebuild? Or did they all go thru a Depot rebuild at some point in their lives before being sold to civilians?

Sorry for all the questions, I don't mean to be a butt head. It's just learning curve stuff I guess.

thanks,
bob

Hi Guys,

Well.....I may have answered my own question. Although my truck SN calls for the firewall mounted ignition filter I found that I have the distributor with the filter built into it on the truck......and the associated wiring harness. So.....like I think John was saying, the truck must have been Depot rebuilt at some point, as I don't think the previous owner replaced the distributor and wiring harness. Now I have to look under the dash and see what's left of the big connector that connects to the headlight switch that I don't have. Ya gotta love this stuff...........

Have a great Memorial Day Weekend everybody!!

regards,
bob