VJNCDave
Bigger Hammer
Wanted to give folks a heads up if they’ve made it far enough to address the electrical side of the Borg-Warner overdrive. There are several relay units new and used available out there but they’re not all ready to work in the VJ system.
It stems partly from the fact we don’t have a starter solenoid. So if you follow the wiring diagram from the original B-W sketch or the ones available from some resellers in PA, MO and KS - you’ll be asked to run a hot lead from the starter, unswitched, and one from the ignition, switched on with the key. And since most of the relays out there were for Ford/Mercury and have only THREE terminals, the math doesn’t work out for the FOUR wires your harness has.
The obvious answer is to use Walcks or Kaiser-Willys and get a rebuilt unit to suit our Willys. But what if you don’t have a good core - like in my case...the ones for Packard, FoMoCo etc will work, just use the hot from the ignition source and ignore the hot from the battery/starter. That’s what FoMoCo did.
For example the one I bought from an overdrive specialist in KS is shown below with letters I’ve applied to help identify them. The one at “C” it turns out is a dead terminal, goes no where inside, does nothing....see pics.
I spent hours and days of back and forth on the phone with this specialist and got nowhere, so I pried off the cover and had a look around. Using a multimeter and a 6V supply, I figured out that “A” should be the keyed ignition voltage supply (+ term on coil), “B” is from the n/c side of the throttle switch (top terms) which continues on to the governor...closing the circuit once above 25 or so mph. This leaves “D” which is the load side of the relay, and this has to go to your OD solenoid, terminal “#4”.
This is essentially a perfect reproduction of the original FoMoCo relay - 3 terminals. At least FoMoCo stamped their case with designations! This reseller’s unit is completely unmarked.
Obviously make sure your solenoid and governor work on the test bench, using a power drill to simulate the road getting up to speed, etc. And for sure, read the original B-W Overdrive manual for the complete mechanical and electrical explanations. It was truly a marvel of engieering.
Stay safe - always disconnect the battery whenever working on your circuits!!
It stems partly from the fact we don’t have a starter solenoid. So if you follow the wiring diagram from the original B-W sketch or the ones available from some resellers in PA, MO and KS - you’ll be asked to run a hot lead from the starter, unswitched, and one from the ignition, switched on with the key. And since most of the relays out there were for Ford/Mercury and have only THREE terminals, the math doesn’t work out for the FOUR wires your harness has.
The obvious answer is to use Walcks or Kaiser-Willys and get a rebuilt unit to suit our Willys. But what if you don’t have a good core - like in my case...the ones for Packard, FoMoCo etc will work, just use the hot from the ignition source and ignore the hot from the battery/starter. That’s what FoMoCo did.
For example the one I bought from an overdrive specialist in KS is shown below with letters I’ve applied to help identify them. The one at “C” it turns out is a dead terminal, goes no where inside, does nothing....see pics.
I spent hours and days of back and forth on the phone with this specialist and got nowhere, so I pried off the cover and had a look around. Using a multimeter and a 6V supply, I figured out that “A” should be the keyed ignition voltage supply (+ term on coil), “B” is from the n/c side of the throttle switch (top terms) which continues on to the governor...closing the circuit once above 25 or so mph. This leaves “D” which is the load side of the relay, and this has to go to your OD solenoid, terminal “#4”.
This is essentially a perfect reproduction of the original FoMoCo relay - 3 terminals. At least FoMoCo stamped their case with designations! This reseller’s unit is completely unmarked.
Obviously make sure your solenoid and governor work on the test bench, using a power drill to simulate the road getting up to speed, etc. And for sure, read the original B-W Overdrive manual for the complete mechanical and electrical explanations. It was truly a marvel of engieering.
Stay safe - always disconnect the battery whenever working on your circuits!!
