Several members are starting 72v coversions.
Moving some of the messages to here.
Those of us that paved the way are doing it the same. I’m sure there are simpler ways by programming can control. I’m a hardware guy, so this is how I did it.
Swap Sevcon controller to a 80v s4 gen 4.
Program coil driver to 48v. Use one 48v contactor wired as built.
Program for dual throttle cloning a Ranger Ev. Uses same throttle.
Program for wired direction inputs.
Throttle p22 and 23, f-p18 and r-p30 needs hard wiring.
Not a difficult wiring job. I will make a harness available for $150.
Loosen lower dash and unplug throttle.
Push throttle plug back to under hood.
Plug supplied extension wire into throttle.
Route it back under hood to original plug with the new connection near Sevcon.
Wire from Sevcon must connect straight through to switch. (diode in line under shrink tube)
Cut wire from Gem ecm must go through diode to switch.
Sevcon supplies 50v active low. Gem 12v active low. Diodes keep 50v from back feeding into Gem ecm.
Original Sevcon controller is subject to many unknown whims from ecm. If there is trouble keeping the controller powered, connect the coil of control relay direct to switched 12v.
Relay coil wires are small red and brown. Cut them leaving enough length to connect new wires.
Wires from ecm are not used. Tape them off.
Other end of harness connects to switched 12v.
If your car did not have an aux battery, 12v was supplied from traction battery tap through a large red wire.
I cut that wire under the hood, leaving it long enough to reach the DCI plug, for constant 12v.
Switched 12v from DCI goes to the dc-dc plug when removing the 48v converter.
The only place to connect the control line to DCI, that is free from “polaris”, afaik, is the wire from key switch that goes to vcm input.
Hey Dave, thanks for posting this tutorial. I am one of the early adopters of Dave’s Kool-Aid mix and have even graduated to the 98 V 24 cell hot rod version everything I’ve got from Dave has worked out fabulously. You just have to have some do it yourself skills.
Me too… my 2016 converted to 72v+ with 24 cells has been working without issue for quite some time now. This is a great setup… especially if you can get your hands on one of the 8kw motors. I think the quirks have been worked out of the controller configs with the 5kw and 6.5kw motors
The newest dvt has an auto-tune for dual throttle. Can’t wait for someone to test it. Iirc, only Grant is using dual throttle. The rest of use may be using a hardware virtual fs1, derived from throttle 2.
If it works well, would sure simplify the conversion harness. I have parts to build harness and kits, but haven’t found a client in ages.
We are talking about the 2016 conversions using oem throttle, however replacement throttles are the lowest cost throttles you can buy.
Unless the source dries up. I haven’t looked in a while. Output #1 will work with classic. Caveat same as the oem Gem hall type. Need T5 or external 5v supply. I may take that back. Each throttle has it’s own power section. Using only one side may work with T4.
