Ford Think Cluster turns on then off, car won't move

Hi everyone, I just found this forum and I hope I can get this Think back on the road. My friend has a Think and it does not move. My friend said that the person who sold it to him, told him that everything works, just need new batteries. He replaced them and nothing. The new Batteries reads 72.7V and that is after about 8 months, so no leakage. I know one of the DC DC converters is out, no horn, lights, wipers… the other one is working, cigarette lighter is reading 12v. I have brake lights and hazards lights. When I turn on the switch, I hear a loud relay click and the cluster turns on. The display is on for a few seconds and then it turns off. I see a picture of a battery with 4 lines, the brake indicator light, the safety alert indicator. I checked all the fuses and they are good. Do both DC DC converters need to work in order for the car to move? What else can I check before replacing parts? Thanks for the Add and help.

The wiring will reach from one dc/dc converter to the other. If that doesn’t work I can send you a shop manual if you need one.

Thanks David. But do both converters need to be operating in order to move the car and keep the cluster on?
If you can send me a manual, that would be Great!!

No, one of the converters only controls the power point/cigarette lighter and the other one does everything else. Strange they did it that way but what do I know.

Manual sent

Got it. Thank you.
Now to try and figure out why the cluster wont stay on and the car not move…

Which switch are you turning on? If it’s the master switch the cluster will turn on for a couple of seconds and then back off. That’s normal. If nothing happens when turning the ignition switch then that is where I would start looking.

oh!!! Yes, the master switch.
Not having the manual or talking with you, I was told that the cluster was supposed to stay on. Great, I now have a valid starting point!!
Thank you very much!!