AMGBA website home page or AMGBA Photo Gallery or AMGBA Club Blog
Subscribe in a reader

Join or renew today and receive a free t-shirt or tech CD, see details in the join the club section at!

Author Topic: Replace Steering Lock Ignition  (Read 11285 times)

0 Members and 1 Guest are viewing this topic.


  • Message Board Member not current AMGBA Club Member
  • **
  • Posts: 4
Replace Steering Lock Ignition
« on: October 18, 2011, 10:23:54 PM »
I need to replace the steering lock ignition on my 1973 MGB GT. Neither MOSS nor Victoria British offer this part. I was told I could use the 1974 or the 1972 part. The 1974 has a plastic wiring connecter plug that would need to be removed and I am not sure about the 1972 part. How difficult is this part to install and which replacement do you recommend?

Jim Wofford
Member number 94-11394
« Last Edit: December 31, 1969, 07:00:00 PM by amgba »


  • chfwrench
  • AMGBA Club Tech Staff
  • ****
  • Posts: 290
  • Membership Number (if known): 91-10014
  • MG information: '73 red B roadster
Re: Replace Steering Lock Ignition
« Reply #1 on: October 18, 2011, 10:43:38 PM »
First, are you looking to replace the mechanical lock or the electrical part of the ignition switch?  Sounds like the electrical switch is the issue.
The mechanical lock should be interchangeable between the years using steering column locks; the electrical switch fits to the back with (3) small screws and all, at least '70 - '72 and then '73 and up.  
Though there were as many as 5 different switches used from 1970-80, it basically came down to the type of connectors on the harness.  
That said, the '73 is unique because it has an extra wire in the harness.  I think it was for the seat belt interlock/alarm used on the early production of that year, but I've never been able to confirm it.  I just know it all works without that wire connected.  I also know that it split the year between bullet and plug type connections.
If you have a plug connection, the Victoria British Ignition Switch (replacement part number 0-315), which is said would fit all 1974-80 and does not show as for '73, should work.  Moss also offers a replacement switch for the 1973 (replacement part number 263-690), which should be the same, but their item description says it only fits the original assembly for 73 and it also notes that the plug must be removed and replaced with bullet connectors.  If you do have the plug connector on the harness and are considering this, best to purchase the entire assembly with the mechanical lock mechanism (Moss part number 263-640 or Victoria British part number 0-319) and make the necessary adaptations, leaving the extra wire open from the car's harness.
If you have the bullet-type connectors, you should be able to use the '70 - '72 switch, leaving the odd wire disconnected.  That switch only comes as part of the complete electromechanical assembly from Victoria British, though the switch should then fit your current mechanical switch.  It just means buying the whole thing (V-B part number 0-317 or Moss part number 263-610), but, it is only about $10 more than the '74 - '80 harness alone, according to the prices from the current catalogs.  The '74 - '80 complete assembly is almost twice that price, so make sure what you actually have before buying anything.
I own a '73 and some years ago, had to replace the ignition switch "on the fly".  The lock tabs on the metal case broke while i was driving and kept coming apart, causing the car to shut down every time it did.  Luckily, someone at the show's swap meet I was headed to had some spares, but from a different year. Mine, an early car built in August 1972, had the bullet type connectors, so I expect these were the '70 - '72 switch, but they did fit the lock mechanism without modification.
As I said, the one extra wire (yellow, I believe) was the only difference and both harnesses - I bought the 2 he had, but have really only used one - did work and I see no discernible difference in their operation.  
I also remember answering another question on the same subject.  You might find it in the old Tech Sections of the Octagon.  I'll forward it to you if I can find it, but I could not to answer you now.
I also suggest you check out other club member's parts stashes and see if someone has one or the other switch around, just to 'try before you buy'.  A swap meet or club meeting may be a good place to find one cheap as well.  I paid about $20 for the pair I bought about 10 years ago and, after testing both, the one I left in place is still going strong.  Famous last words.....
I hope that helps you.  Let me know how you make out.

Art Isaacs
AMGBA Tech Staff


   AMGBA website home page or AMGBA Photo Gallery or AMGBA Club Blog