main wiring harness

circleburner12 · Post by **circleburner12** » Sun Feb 16, 2014 7:01 pm

is there a difference in the main wiring harness between an m38 and m38a1?.

ive got a 1950 m38 that needs a harness, but today I came across a brand new main harness that I believe is for an m38a1. the box the harness came in is dated 11/53.

Post by **wesk** » Sun Feb 16, 2014 9:29 pm

There are quite a few differences. It depends on the serial number of your M38. If you spend an hour in your ORD 9 you will be able to decipher which harnesses differ in what ways. IE the first M38's had a separate cannon plug with a separate harness from the light switch to the trailer receptacle until MC35387. Then the 3 circuit breakers and their wiring disappeared on the inboard side of the cowl battery box at sn 65927. Gauges had external resistors until MC17855. Wire # 12 ended at the firewall through MC20599 which had a firewall mounted radio noise filter. The aux power plug on the firewall ended with MC47771. The CB on the instrument cluster went away at MC 65042.

So yes you can adapt the M38A1 harness to the M38 but you will have several modifications to due plus those mods needed for changes in lengths and location of components.

circleburner12 · Post by **circleburner12** » Mon Feb 17, 2014 7:54 pm

it has the early headlight switch along with the early components. well it looks like i'll sell the wiring harness along with the 24v parts i got. and make a down payment on the correct harness. thxs

Post by **wesk** » Mon Feb 17, 2014 9:26 pm

It would not be that difficult to alter the A1 harness. Definately cheaper then the $750 + for the correct harness. What is the part number on the A1 harness?

circleburner12 · Post by **circleburner12** » Mon Feb 17, 2014 9:57 pm

on duty at the firehouse tonite. i'll get it off the box tomorrow and let you know. thxs wesk

circleburner12 · Post by **circleburner12** » Tue Feb 18, 2014 1:16 pm

heres the box tag info.

osn g758-83-29662

wo-806410

da-33-019-ord-1268

burton packaging company

date-11-53

thxs

Post by **wesk** » Tue Feb 18, 2014 8:21 pm

M38A1 main lighting harness.

You just need to modify your new harness so it matches the lower wiring diagram. You will need the second smaller plug for your light switch. separate the rear lamp wires from the M38A1 harness that should only run to the rear and add them & the remaining rear lamp wires to that small plug. Where you pick up power for wire # 15 depends on weather you have thye 3 circuit breakers or not. If you have trouble with the diagrams email me.

circleburner12 · Post by **circleburner12** » Wed Feb 19, 2014 7:38 pm

wesk I cant find your email address. could you send it to me in a p.m. thxs

circleburner12 · Post by **circleburner12** » Tue Mar 04, 2014 8:21 pm

i might go ahead and sell the harness. it's like brand new for a 60yr harness and way to nice to try to modify it. thxs

QCIM38A1 · Post by **QCIM38A1** » Wed Apr 30, 2014 3:34 pm

If you still have that harness, I have a '53 M38A1 that might like to have it....

circleburner12 · Post by **circleburner12** » Wed Apr 30, 2014 5:38 pm

sorry should have posted that the harness is gone. thxs