Sync cord problems with old Substobe TTL

I have had a Nikonos V with an Ikelite Substrobe TTL 100 since the early 90's that I am just now starting to use on a regular basis (moving to the Caribbean helped in that regard). Even though I have the strobe set to TTL the photos consistently appear overlit and washed out. It also does this with an old-style TTL Substrobe 225 I recently acquired. I am wondering if the problem could be with the single-strobe syc cord which is close to 20 years old. Is there a way of testing both the camera and cord without sending them out? I also have a brand new dual sync cord that I assume should work perfectly. I have no problems buying a new cord but would rather not if that is not the problem.

If you own a multimeter you can test continuity of the wires in your sync cord to check that none are broken. Four out of the five contacts are connected on older non-digital cords.

There are testing instructions for sync cords and strobe bulkheads here:
SYNC WIRING

And there is some information about testing TTL here:
Substrobe FAQ

Regards,
Jean / Ikelite
IKELITE Underwater Systems

could be the camera itself..or could be maybe a non ttl cord..how many pins are on it?.when was the last time the camera was serviced? I had a Nik V that I sent out that I had no problems with,just wanted to get new o rings and a cleaning..I had no issues with any of the functions.Turned out that Bob at Southern Nikonos discovered that my electronics that worked ttl function was not working at all.I never noticed it because I alway shot as if in manual using strobe as a fill and held it at proper distance for whatever power setting I had it on..strobe was ike 150- .