So far so good on the solenoid.

Drove up to the All British Meet in Portland yesterday.  This little stinker is just a kick to drive.  As long and you don't need to go over 70.  It tracks so straight you can take you hands off the wheel!  Had a little idle issue so when I got home I got out my balancer I use for the dual SU's and my Webers.  Adjusted the linkage for idle and 2000 rpm. One more nice day before fall, leaves are falling already, so I'll take my three cars out for a little exercise, 65 Vette, 72 Porsche, and 93 Mini.

Great idea.  Today takin her up to the All British Car Meet and Race in Portland.  One more great day in the Northwest before the rain comes next week.

I'm glad a new solenoid got you going.  For your peace of mind, carry an old pair of disposable pliers with you.  If/when the round solenoid fails, you can put the car in neutral, turn the ignition switch to "run", and bridge the two solenoid power terminals with the pliers to get the engine started.  I have had to do this more than once with the round solenoids.

Well I finally got the round solenoid yesterday.  Installed right away with no issues.  She started right up.  Then I tried the button on the bottom, that's slick.  So far so good, now I'll see how long it lasts as one of our contributors suggests.  Washed the car and took it for a spin, nice to have it running again.  Today will take it to the golf course and Costco.

Anticipate that the new round one will fail in a relatively short time.

Inside the round one there are a couple of circlips on the shaft moved by the electromagnet.  The circlips pop off the poorly machined grooves on the shaft and then you will hear them rattle as well.

Remember the Ford solenoid.  Generics are available and usually in stock at places like Advance Auto Parts for about $10.  All you need to do to use the Ford solenoid is make up a short wire with spade terminal for the white/red wire to connect to and move all the wires from the old solenoid to the Ford one.

Be sure to let us know how this plays out.

In fact I did open up the old solenoid and it looked like the spring that holds the moveable shaft away from making a connection was broken.  After hooking up the new "square" solenoid I had the same problem as before.  I removed it from the car and tried some continuity checks and lo and behold it was rattling like the old one and if held upside down you had zero ohms across the two connections.  Then turn it around and it showed an open between them and it rattles.  Well it's brand new out of the box and that's why I ordered the round one.

??? Why ???

I mentioned in a previous post that the cylindrical solenoids were NOT good.  Why did you buy the solenoid that has known problems?  The square Lucas solenoid is much better and by drilling out rivets you can take it apart and service it if you really want/need to.

I also mentioned that if you are in a rush, want something local, and are not a stickler for originality, ask the local parts store for a solenoid for an early 1970s Mustang.  They are typically in stock with prices as low as $10.

Save yourself the frustration.  Don't buy the reproduction cylindrical solenoid.

EDIT:  You also said that you and a buddy checked out your old solenoid.  Before you spend any more money, disconnect all the solenoid's wires and remove the existing solenoid from the car.  The suggested measurements below are for AFTER the wires are disconnected and solenoid has been removed from the car.

The solenoid mounting foot is its ground.  When installed it must be on a bare metal surface.  If you fail to attach the solenoid to a ground or insulate it somehow, the solenoid will not work.

When you measure across the two threaded studs on the solenoid there should be infinite resistance.

If you connect the solenoid to a battery or battery charger such that the mounting foot is ground and the small spade lug gets +12V you should hear a "click" as the solenoid closes.  While the solenoid is closed you should measure near zero ohms resistance across the two threaded lugs.

The threaded stud near the mounting foot gets the cable going to the starter motor.  

The threaded stud furthest from the mounting foot gets the battery cable and ALL the brown wires.

Well I sent the solenoid back to our host and cylindrical one is enroute.  Hope it will solve my problem.  Losing some good driving weather.

For the future, if you are not stuck on originality or "must use" Lucas parts, you can pick up a Ford solenoid (for say a 1975 Mustang) and use it instead.  It won't look original and you have to improvise a terminal for the ignition switch wire.  However, even the generic aftermarket ones are very good and they are typically inexpensive.

Some troubleshooting today with a friends help.  Looked at everything.  Even tried his remote starter switch.  There is an intermittent problem with the new solenoid.  It is the square one.  We did repeated tests with no voltage on the unit and with voltage.  We found continuity where it wasn't supposed to be and then the same check found an open. 

Well calling our host tomorrow and sending it back, hopefully with a new one to replace it.

For reference, the spade terminals for the brown wires on the threaded post do not constitute additional terminals.  It sounds like you have the two threaded posts and the spade terminal for the white/red wire.  That's the common 3 terminal solenoid.  

One more question.  Are you using the rectangular solenoid or the round/cylindrical one?  If you are using the cylindrical one, replace it with the rectangular one.  The cylindrical ones fail very quickly and are of particularly bad quality. 

All the wires on the solenoid are brown except the white/red from the ignition switch.  One spade in front of the B+ connection and one behind, with the ignition connection lower/behind and between the two main connections.

At first I thought it was the ignition switch stuck in the on position.  However when it stuck again and I pulled the white/red wire off the solenoid and it kept spinning I thought maybe something else.  Now I'll check again and maybe there is so much current running through the solenoid that removing the trigger from the ignition switch wasn't enough to release the solenoid connection, except that's the way it's supposed to work normally???????

The external solenoid for the inertia starter should be either 3 or 4 terminal, not 5.  There should be a threaded post with the battery cable and all the brown wires, a threaded post with the cable to the starter motor, and one or two spade terminals.  One spade terminal will get the white/red wire from the ignition switch.  If a fourth terminal is present it will be smaller.  It will have a white/yellow wire that goes to coil (+).  The white/yellow wire is only used on ballast ignition systems.  You could argue that the mounting foot of the solenoid is a 5th terminal as it must be grounded.

If your car's wiring is for a '93, it originally would have used a starter relay for the pre-engaged starter.  The white/red wire would go from the ignition switch to the relay.  Something like a brown/red wire then leaves the relay and goes to the original pre-engaged starter.

If you still have the starter relay fitted its contact may be stuck.  What color are the wires on your solenoid?

93 Mini, engine is placarded as a 1380, possibile.  External solenoid with 5 connections and an inertial starter.

Sorry, I am coming to this thread late. 

What vintage is the car?  Which solenoid is/was fitted (both new and old)?  Which starter motor is this (inertia or pre-engaged)?

Calling Jet Motors today, then back home from my trip Friday so I'll mess with it again this weekend.  Miss driving her!

As long as the break away bolts are not broken off already. In that case i cut a slot in them with a dremel or cut off wheel and unscrew them with a screwdriver, easy peasy.

Kolsen, The Ignition switch on any Injection model is a "doddle" to fit. Just be careful when taking off the Securing Bolts on the Steering Column. Maybe I've been lucky, but every one I've taken off has released dead easy.

After reading your first post I thought  solenoid. But onetim already said it. Maybe it’s the ignition but if the switch doesn’t stick I doubt it. I would return the solenoid, tell him it doesn’t work and get a new one.  Now I don’t own a 94 but I would bet you that ignition switch is a B@!@h to get in. Or you could buy both and keep one as a spare. My ignition failed so I bought one this summer, it was only a few dollars.

Well the solenoid checked out ok.  Took it out of car and checked with ohm meter while tapping with plastic hammer, ok.  Then put back in the car hooked up all leads with electrical tape covering them and as soon as I touched the battery lead the engine tried to start.  Hmmm. I removed the lead that goes to the ignition switch and it still wanted to turn over when I touched to battery cable to the solenoid post.  I'm going to think about that for a bit and maybe order a new ignition switch.