Contactor not working

Ford Electric Car Forum Ford NEVs
1

Any chance anyone knows why my Ford Think contactor won’t close? I’ve tested the contactor on a bench with a 60V dc power supply. It clicked and closed the connection, so I know the issue isn’t the contactor. I also have ground on the contactor terminal 1. I don’t have 72V on terminal 2. Below are the steps I did so far. To note, the cluster comes on but it doesn’t look like I’m getting 72V (terminal 7) out to the contactor.

Step 1: Is the battery pack voltage at least 68.3 volts? Yes
Step 2: Turn the drive mode selector switch to the Reverse, Turf or Drive position. Check the instrument cluster gauge.
Is the instrument cluster gauge charge icon activated? No
Step 3: Turn the drive mode selector switch to the off position. Disconnect the motor controller harness connector. Turn the drive mode selector switch to the Reverse, Turf or Drive position. Connect a DVOM between motor controller harness connector terminal 11 and the vehicle chassis. Does the DVOM display approximately 72 volts? No
Go to step 6

Step 6: Connect a DVOM between contactor terminal 2 and the vehicle chassis. Does the DVOM display approximately 72 volts? No
Solution- REPAIR circuit 41 (OR/VT). OPERATE the system to verify the repair.
Problem with the solution: I performed a continuity test ont eh OG/VT wire between contactor terminal 2 and instrument cluster terminal 7. It tested as good, telling me it doe not need repair.

Additional testes performed:
*I checked ground from motor controller terminal 11 BK/GR to contactor terminal 1 BK/GR. It rang out on my dmm.
*I connected a fused jumper wire between motor controller connector terminal 11 and the vehicle chassis to check if it closed the contactor. It did not. If it did, it would imply the contactor is bad.

2

For additional context, the instrument cluster came out of another Think where it was closing the contactor properly. I put the IC back into that cart and now that one doesn’t close the contactor either. Looks like the issue is the IC. Is there any documentation on what PCBA component needs to be replaced?

3

Go to You Tube and look up Hagan Walker (hagan92). He has several videos on the Ford Think. He also offers repair on the cluster. His website is Fordthink.org

4

I was able to narrow the issue down to a defective rectifier on the IC board on circuit 41 (Pin 7). There was also a burnt trace that connects pin 7 to pin 2 that was repaired. Now I’m questioning if there is an issue with my controller. I bench tested the IC and now I get 72V to the contactor output pin 7. Going to check the harness this weekend to see if there is a short in either of the two wires OG/VT or WH/BN. The IC worked fine before taking it out of my other Think which leads me to believe it’s either a shorted harness wire or the controller.

5

FSIP rebuilds controllers. If you sign up for a business account, you will get a big discount.