Unless I missed something in the schematics, I can’t see a need for the DC/DC converter except for lights, horn, wipers and so on. Since I am not using any of those, is there any reason to keep the converter in the circuit? Did I miss something?
Depends on year of car.
Gen 1 (00-04) - No
Gen 2 (and above) (05 ->) - Yes, and no. 12vdc is on the PSDM and some of the car safety loops.
Perhaps you should be asking:
Does the GE Controller need external 12vdc to operate? → No.
Do you have the GE Controller Tech document?
Mine is an 01.
I have the GE Manual and I can see from that there is no need for the 12v. That is partly my reason for asking. So tracing the actual wiring thru, (at least the stuff I hadn’t pulled off), I see the constant 12v goes to the key switch. From there thru the charger interlock and from there this really long green wire that I pulled from somewhere… ha ha…
I believe that green wire connected to a small relay that I assume was an interlocking relay so the key didn’t have 72 volts on it. That relay is NOT on any schematics. I assume it was a modification that was never put on the drawings. (common?)
One other thing I see that isn’t part of the 12v string is a NC contact on the drive schematic. That is factory jumpered on my drive to pin 2. Reading the pin descriptions it appears to be a motor thermal that I assume doesn’t exist on mine.
Yes, What your had was the DC Converter update and is a separate tech doc.
Save these extra components and connectors that you are removing as there are people looking for them to convert their original car wiring to the new DC Converter. The factory no longer provides this wiring update.
You are partially correct in your observations. That green wire of unreasonable length is the Keyed wire that went to the funny looking relay (which I think comes from the air conditioning world). At KeyON, that relay connected B+ to p2 on the controller and wakes it up.
But first:
p1 is the pre-charge wire and gets B+ when Main Batt Sw is connected. This must happen BEFORE p2 is keyed ON.
That NC contact on the far right (curiously not labeled in parts of the Tec Doc, but is found elsewhere) is indeed the thermal switch on the motor. When OPEN, it puts the controller in a low power mode. When CLOSED, it sends B+ to P21 on the controller. You might want to try this (instead of programming) to make this car go slow.
A direction must be selected before pedal press. Put B+ on P4 or P5.
P3 is Start switch (is in the pedal) and wants to see B+. It needs to be open at KeyON, then closed right before pedal pot sends V increase to P8.
B- (Batt NEG)
P13 is Handbrake switch. You can use it or not. B- (Batt Neg) needs to be on P13 to go.
The weirdly labeled circle with the L is the Main relay. One side of the coil is B+ and the other goes to P11. I believe the controller looks at P11 to see if there is B+ at KeyON, to determine if the Main Relay is Ok. then If all safety tests clear, the controller takes P11 low and closes the relay. If for some reason the safety tests fail, it will not close the relay.
Thank you sir for taking the time to write all that out… I actually knew all that about the drive itself, but others that read this may not. I also was very glad you knew about that long green wire.
I’m a retired control systems Eng. I used to do a lot of motion control and DC is actually my specialty. But… That only means I know what I know, and there are a lot of things about these cars that tribal knowledge like yours will help save time on. I for one appreciate the time you and others take to help us that are just getting started in this “hobby”. (read: “addiction”)