S124 300 TE 24 - 722.5 5th gear missing

[zohar.melamed]

Time to try and find the missing 5th gear on the S124 ( 722.5 )

Has been mia since purchase but I mostly drive in town so was not a priority.

Am I right in thinking this page shows the diagnostic procedure ?

If so can anyone explain:

1. The two diff symbols in the left and right ‘test connection’ columns ?
2. Where on a 1991 300 TE 24 is connector N15/1 ( I assume the connector for the HGS gearbox controller - but where is the controller?).
3. Cruise control works fine , no lights on dash , I have checked the little micro switch on shifter and that’s fine. Any ideas? Car has ASR

Cheers
Zohar

 

[alabbasi]

722.5 is not a true 5 speed but a 4 speed gearbox with a separate overdrive unit bolted to the back of it. I suspect that it's not engaging. Aside from knowing this, I know nothing else about the 722.5 so I have no advice to offer.