Just curious:
Do you know if the battery was used to heat the engine block or if this circuit was used to heat the battery if the engine block heater was connected?
24VDC in from optional engine block heater. When engine block heater was plugged into AC, it would use an included AC-DC converter to send 24V to that plug. The car would heat/charge the battery based on some criteria.
The connector is present on all models, but it is only relevant on the 05-08 models with the jump starter.
Cool. I'm going to have to jump start my 2009... looking for a clean way to leave a jump start cable in place and that connector location is perfect and on the booster side if I'm correct.
It's just the wrong sex and not really a high voltage terminal. If I were able to get a high voltage panel connector it would be better.
install power supply with diodes attached to vestigial connectors in the place formerly occupied by the jump starter. Fish an AC power cable out through a drilled hole and sealed with a grommet.
For those looking for a storage case for your charger, this works really well for $18. It's a link to Amazon, I have no connection to the product or seller(s).
Posting in a dead thread again. Sorry.
I built this. and I cant get it to work and I have no idea what I am doing wrong.
I charged it using the self built charger, the orange plug is in "locked position".
Charged for 6h, made it to 345v I think. I cleard codes via forscan. Didnt turn over.
Unplugged the 12v battery, sat for 10min. Plugged it back in, the Stop Safe message still flashed, cleared codes, and still wouldnt turn over.
Let sit overnight.
Hybrid battery at 332v. Put 12v on trickle charger for 1h. Stop safe message still there. Cleared codes, still wont turn over.
At all times the car with red lock in bottom left hand side of dash present.
I am near tears here. I need my ride back. What am I doing wrong?!
2009 FEH, 110k miles.
codes after clear
Last edited by wing43215; Feb 27, 2026 at 01:11 PM.
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