Problem with wiring loom from the computer under the passanger floor?

[Vintage1942]

I was told by a mechanic that error indications on my dashboard for malfunction on parts of the system is probably caused by wiring problems in the wiring loom from the computer in the passenger foot well to the instrument panel. He claimed that this wiring loom as supplied in original version frequently has problems. Has anyone else had similar problems and if so how have you fixed it? Repair or new loom?
I would appreciate any suggestions.

I have understood from other discussions on the subject of the computer that it is using a 2-wire bus. I did not check that before placing the question (which was not so good) and this makes me wonder if the guys that tried to set-up my computer really knew what they were doing.

Sorry for posting a not very valid question.