Re: M37 signal lights
Posted: Sun Jun 07, 2015 12:45 pm
And just to make it more confusing, there were two types of turn signal equipment.
The first (early) used a hybrid lever switch and control box to multiplex the stop/turn function into the mix. It was complex, prone to failure due to many active components in the box, and is rare now. It was also found on the 5/4 ton M715/725 Jeep trucks. That switch has wires coming out of it with terminal lugs applied to connect to the control box.
The later system used a standardized switch lever with a MS-series connector on the switch and a Bendix connector on the flasher unit along with rubber Packard connectors for interfacing into the main wiring loom. The earliest (and proper) of those uses a green indicator on the tip of the lever switch. This design didn't pan out very well, as the smacking of it up or down caused the 313 lamp in the handle to fail early & often. Later (and current) switches have the indicator lamp located in the switch body.
Both systems use the topology of one lamp on each rear side for the stop/turn function, as all M-series vehicles did. If you have a separate lamp for each of those functions, something improper from a civilian system has been imported and your NATO standard trailer receptacle will cause problems when used.
Both systems required the modification of the rear lighting layout. The proper way was to remove and discard the original BO marker & stop housing on the right, and add another service stop/tail/ BO marker combination housing as found on the left side. A separate BO stop housing (very similar to the M38/M38A1Jeep front BO marker) was added using a new bracket mounted under the new right side combo light.
Both modification systems required the addition of another wire from either the control box (factory done in later B1 production) or switch to the right rear stop/turn lamp and the proper pin in the trailer recep.
Dennis aka PoW
The first (early) used a hybrid lever switch and control box to multiplex the stop/turn function into the mix. It was complex, prone to failure due to many active components in the box, and is rare now. It was also found on the 5/4 ton M715/725 Jeep trucks. That switch has wires coming out of it with terminal lugs applied to connect to the control box.
The later system used a standardized switch lever with a MS-series connector on the switch and a Bendix connector on the flasher unit along with rubber Packard connectors for interfacing into the main wiring loom. The earliest (and proper) of those uses a green indicator on the tip of the lever switch. This design didn't pan out very well, as the smacking of it up or down caused the 313 lamp in the handle to fail early & often. Later (and current) switches have the indicator lamp located in the switch body.
Both systems use the topology of one lamp on each rear side for the stop/turn function, as all M-series vehicles did. If you have a separate lamp for each of those functions, something improper from a civilian system has been imported and your NATO standard trailer receptacle will cause problems when used.
Both systems required the modification of the rear lighting layout. The proper way was to remove and discard the original BO marker & stop housing on the right, and add another service stop/tail/ BO marker combination housing as found on the left side. A separate BO stop housing (very similar to the M38/M38A1Jeep front BO marker) was added using a new bracket mounted under the new right side combo light.
Both modification systems required the addition of another wire from either the control box (factory done in later B1 production) or switch to the right rear stop/turn lamp and the proper pin in the trailer recep.
Dennis aka PoW