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Author Topic: Ignition Switch Replacement  (Read 5075 times)

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december2014

  • Message Board Member not current AMGBA Club Member
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Ignition Switch Replacement
« on: January 19, 2015, 11:25:11 AM »
My '79 Midget has a headache. The ignition key is frozen solid in the ignition switch, and you can't turn the switch to start the car. I looked in the service manual to see how to replace the ignition switch, and that is sure a job! Remove air duct hose, disconnect the steering shaft from the rack and pinion unit, pull things outward and downward while disconnecting the electric stuff, then drill out the one-direction screws for the ignition switch unit, and so forth.

Is there an easier fix to try? Maybe grab the ignition key with vice grips, work things back and forth, and hopefully break loose the obstruction? Appreciate any advice.

Bill Fortenberry
Warner Robins, Georgia
« Last Edit: December 31, 1969, 07:00:00 PM by amgba »

Art

  • chfwrench
  • AMGBA Club Tech Staff
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  • Posts: 246
  • Memberhsip Number (if known):: 91-10014
  • MG information: '73 red B roadster
Re: Ignition Switch Replacement
« Reply #1 on: January 19, 2015, 11:32:05 AM »
Sorry for your troubles, but the method described is reasonably what needs to be done.  I can short-cut a few things to make it less involved, but it is pretty much as you are seeing it.

I've never had to drop the column from the instrument panel.  A lot of work and a big pain to do.  Also, while there has been known to be wear and/or damage to the electrical switch at the back of the lock (ignition switch - Victoria British part number 0-315), it is usually in good shape.  It can be removed by loosening the 3 very small screws that hold it to the lock. If in good shape, you would not have to address any wiring, just the lock assembly (Victoria British part number 0-319; about $100). I'm not sure that includes the shear bolts (p/n 18-017), but they can be ordered separately.  You can also try starting your car using a needle nose pliers to turn the switch shaft.
Next, have you tried spraying WD40 into the switch and then turning the key while 'rocking' the steering wheel?  Also, not so obvious, remove the steering column covers and then ignition switch ( the electric piece on the back of the lock opposite the the key described above) and try using a screwdriver or other tool to move the lock from the back side to loosen it while again rocking the steering wheel and key.  Douse it all well with Liquid Wrench or WD40 beforehand.  Requires 2 sets of hands and sometimes works, it is usually what everyone has already done first, but just a thought.    

Now, assuming the thing is really stuck good.  The ignition switch assembly is held in place with 2 break-off bolts.  The heads break off on tightenting to prevent theft and tampering.  Bad news is they cannot easily be removed.  Good news is they cannot be overtightened, so are usually fairly easy to extract once drilled or slotted, if you use those methods.

From there you a few choices, all involving the use of a cut-off wheel and either a drill, Dremel tool or an electric or air powerd cutter (all available cheap from Harbor Freight, if you don't have one). Making sure all other wires and apparatus (i.e.: signal lamp and wiper controls) are either clear, covered or removed from the steering column, see how easy it is to access the tops of the bolts.  See if you can center punch the top of each bolt to give a place for a drill bit to find and start.  With the drill or a bit in the Dremel tool, try to drill a hole in the top of each of the break-off bolts for an an extractor tool to remove them.  The extractors are also available from Harbor Freight or Sears if you don't have them.  Not as easy as it sounds.  Besides the lack of clearance in the interior to do this without damaging something (why they go with dropping the column), the bolts are designed to be tamper-proof, so getting the punch centered and then gaining any kind of traction accurately with the drill is difficult.

Some have also tried to use the Dremel (preferred because it is smaller) to cut across the bracket into the tops of the shear bolts to create slots so as to be able to use a flat tipped screwdriver to remove the bolts (hence the remark about not being over-tightened).  Again, accuracy is not as easy as it sounds and after 30 some odd years, the bolts could then be frozen in place to the lock and unable to be moved with just the screwdriver.  

My preferred method is to use either the Dremel or an air powered cut-off wheel to attack the upper bracket that hold the switch to the column or go in from the sides to cut the the bolts themselves.  Either way, it destroys the lock and brackets, but they're useless anyway.  Faster with less of a chance to do other damage, this can be done fairly easily, though I advise caution and taking your time as to not risk cutting anything else or damaging the column in either cutting, chiseling or prying away the brackets.
The lock has a pin that goes into the column to hold the shaft from moving when locked.  It generally just drops out, but from years of use, can be slotted and caught on the column or covers, so be careful in handling not to damage the sheetmetal column covers maneuvering it out. Installation is fairly straight forward; with the lock going back in 'unlocked' (column lock pin retracted).  Just check the alignment before breaking-off the bolt heads or you will starting over again.  

I hope that helps you.  Let me know how you do or if you find anything else.  

Safety Fast!
Art Isaacs
« Last Edit: December 31, 1969, 07:00:00 PM by amgba »
Art Isaacs
AMGBA Tech Staff
chfwrench@aol.com

december2014

  • Message Board Member not current AMGBA Club Member
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  • Posts: 9
Re: Ignition Switch Replacement
« Reply #2 on: January 19, 2015, 11:33:11 AM »
I do have a Dremel tool with lots of accessories for it, including various kinds of cut-off discs and cut-off wheels. One cutting wheel is titanium, and it will cut hardened steel almost like a hot knife through butter.

A few more questions please:  
You didn't mention specifically about disconnecting the steering shaft from the rack & pinion, so the steering shaft can be pulled forward to give access to all the things inside the steering column covers. I assume disconnecting the shaft is definitely needed, and once you've done that, you can pull the steering unit outward toward the interior of the car (away from the dash / instrument panel)? What do you do then, to drop the unit down some to work on things? Or is that even needed once the unit is pulled outward sufficiently?  

In replacing the electric ignition switch, the book says there are two kinds. One has bullet connectors. The other has a single square plug. I guess you'll see what kind you have when you get in there.

After reading what you sent me, and what the book says, I've decided not to re-use or repair any of the old parts. I plan to replace the steering lock, ignition switch, etc. with all new parts. Hopefully Vic Brit or Moss has everything needed. I wouldn't want to be driving and suddenly things lock up so I can't steer the car. That would be real bad! Or I pull in somewhere and park, and find the key jammed so I can't turn off the engine. Or I find the key locked up (like now), so I can't start the car to drive home.

So, I'll simply be cutting off all the old parts with the Dremel, including that bracket you mentioned. That should save time. No working to drill and extract those 2 break-off bolts and so forth. I'll be real careful not to damage any electric wires or the column as I'm cutting off things. Once all the old parts have been removed, I'll install the new ones. Thanks for giving me the part numbers for a lot of what I'll need in the way of new parts.

When I replace things, I won't use new break-off bolts. I will see if I can find regular bolts or screws the right size, in case I ever need to go in there again to do some work. I'm not worried about someone working their way into the assembly to remove those bolts and steal the car. If I can't find regular bolts the same size and thread as the break-off bolt holes, I can drill those holes a little larger and use one of my taps to accommodate a regular fine thread SAE bolt.  

I might remove the driver seat to give myself more room to work on the steering assembly. On my 1961 Midget, removing a seat is real easy, just 4 bolts. I hope it is equally easy on the '79.

As you requested, I'll let you know how things work out with this job. And if I encounter any hiccups I'll send you the  question(s).
Thanks again for taking the time to answer me with so much detail and all the great info,

Bill Fortenberry
« Last Edit: December 31, 1969, 07:00:00 PM by amgba »

Art

  • chfwrench
  • AMGBA Club Tech Staff
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  • Posts: 246
  • Memberhsip Number (if known):: 91-10014
  • MG information: '73 red B roadster
Re: Ignition Switch Replacement
« Reply #3 on: January 19, 2015, 11:34:02 AM »
I had said that pulling the column down and certainly disconnecting it from the rack should not be necessary.  I've worked mainly on MGB's, but the lock mechanism is exactly the same assembly and even carries the same part number as the Spridget in the V-B catalogs.  On the Bs, I've only had to loosen or remove some bolts on the column to facilitate snaking the ignition wires through, not to remove or drop the column.  I do not remember the exact distance, but clearance to the dash would be similar to allow travel of the collapsible column in the event of accident.  Without need to access the top of the mechanism with a drill, you should be able to remove it from the sides with the cut-off and install it without pulling the column forward.  Removing the seat would be a good thing for work room or if just to keep the filings off it.

Unless it is damaged, I would not replace the ignition switch. It will not lock-up, but I would test it operationally and check that the metal back case is tight to the plastic front cover.  The plastic cover is held in place with metal tabs that are known for coming loose or even breaking off (usually after a repair of the switch guts).  A loose case will ultimately cause internal connection problems, often resulting in stalling while driving, but would not lock the wheel. Mine broke this way on the road travelling to an MG show/flea market in NJ.  I used tape to hold it together just to get to the show and then bought (2) used spares for $10 each at the flea market just to get home.  The one that I put in at that show is still in place and working; the second still in the boot just in case.  That was almost 10 years ago.

The switch is removable from the back of the lock, as mentioned, and can be left hanging (albeit with possibly cutting some zip ties or harness tape to move out of the way.  If you do plan to replace it, you'll need to check under the dash to see which connectors you have. Don't order anything until you have made that determination or are prepared to change connectors later.  It does not follow exactly by year. Damn things last over 30 years if maintained, so I would not sweat the break-off bolts.  The bolts breaking assures the proper torque as much as to provide security.  You may also find standard hex head bolts will not properly fit the bracket, the heads being too large.  A narrow spacer of some kind (aluminum or copper tube) may have to be fabricated, but then they may interfere with the covers.  I'd suggest trying to find cap (allen type) or torx bolts if you go with something more conventional.  Threads, though Whitworth, will correspond to SAE standards, usually fine thread.  I'm not sure the size for the column, but you can go to a machine shop or automotive hardware and try some nuts on a removed bolt (or bolts into the removed lack casing) to find what you need.

I enjoy working with everyone and glad if this helps you.  I hope I did  not miss anything, so write, send photos and ask questions.

Take care and good luck.

Art Isaacs
Art Isaacs
AMGBA Tech Staff
chfwrench@aol.com


 

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