I found a wiring diagram for the GM charging system, but I have no idea other than the + and - post (on the HV battery) to connect to. I'm about ready to close put it all back together and drive it until it dies.


Pages D-48 through D-51 show the Hybrid charging diagram.

https://www.gmupfitter.com/files/med...hassisCabs.pdf

 

Here is my battery pack, I assumed I would connect to the external posts, on the left side. Then I tried the internal posts. Neither worked on changing the meters to see the battery volts/amp. Any thoughts on where to connect?

 

I have no idea how the wires are routed in that pack. I've never seen the insides of one, and I can't tell from your picture.

I have attached your picture with the main (+) end circled in green. The main (-) is on the same side of the pack at the extreme far end.

With the safety plug installed, you should get full pack voltage between these two points. If not, then the pack may also rely on a relay as well. However, knowing those two modules are the end points, you should be able to figure the circuit out.

 

Thanks for the info! I'll tackle it once I have another free weekend. One more question, shouldn't the electronics be isolated so they don't fry during the charging?

 

The car likely charges at 90A and discharges at 150A. I doubt there will be any issues. Toyota and Honda packs have grid charger systems with no issues.

You're using an isolated power supply. Provided you don't accidentally short something, you should be fine.

You also need a diode in the HV lines of the PSU, or you will damage it.

Furthermore, you need 3 light bulbs wired in series.