Author Topic: Ignition Switch Problems  (Read 379 times)

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Offline 4129R

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Ignition Switch Problems
« on: Thursday,September 16, 2021, 08:54:23 AM »
I am just testing out all the electrical circuits on 4376R after fitting a new loom. This is not a job for the faint-hearted.

After charging up and connecting a new battery, I turned the ignition switch to see what would happen and nothing, not a squeak.

I traced the white with red wire from the switch to the starter, and the wire was continuous.

I tested the voltage of the thick brown wire at the ignition switch, 12v as you would expect.

I took the ignition switch apart, removing it from the key part in the column, and disconnected the wires on the back, tested the connections, and they all seemed to work. You need 3 hands to do this, hold both meter probes on the contacts, hold the switch, and turn the switch with a screwdriver. It is possibly but very difficult with only two. An octopus would find it easy.

So last resort, test the voltage at terminal 1, the white/red wire to the starter. 12v from the thick brown reduces to 6v coming out of terminal 1. Time to pull the switch apart.

There are 3 crimps on the aluminium case holding the terminal plate in the body. Ease those apart with a screwdriver, then move over a clean surface, then carefully pull apart, expecting things to spring out.

It was not too dramatic, but the terminals which make contact when you turn the switch, were horrible. I got some fine emery paper, and rubbed the contacts on the paper until there were all gleaming. Carefully put the switch back together, now there is only 1 position it all fits together, crimp the three cut outs to hold the plate to the body, mark the terminal connectors on the metal body, 1,2,2,3,3,5,5, connect the wires, reconnect the battery, and try with a screwdriver. Bingo. The starter turned over well with the plugs out, but no oil pressure. The battery went flat before oil pressure registered. Leave the battery on charge, and try again tomorrow when my brain recovers.

Next ignition switch problem, has anyone managed to find someone who has all the ignition keys, or does someone know a locksmith who can get a key to work in the ignition switch barrel. I have a few barrels without keys to fit, and the whole ignition switch/key assembly is very expensive.

Back in the day, my local garage used to have all the door and boot/trunk keys for minis, so they were available, I just need to find who has the set for ignition locks. 
« Last Edit: Thursday,September 16, 2021, 08:59:05 AM by 4129R »

Offline jbcollier

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Re: Ignition Switch Problems
« Reply #1 on: Thursday,September 16, 2021, 09:40:44 AM »
Take your switch and key to a locksmith ands they can sort you.  Make sure you lube the ignition switch.  I use dielectric grease on the contacts (not too much).

Digital voltmeters are amazing things but they will "smell" a voltage across the dirtiest, vilest connections imaginable.  Use a 12v test light with an incandescent bulb.  This applies a load to the circuit giving a truer picture of what's up.

How much cranking did you do?  I crank for 10 second intervals, no more than 4 or 5 times.  If there is still no oil pressure, I would remove the oil pump and pack it with vasoline (I ALWAYS do this when rebuilding an engine).  Can't remove the pump?   Remove the filter and use a large veterinarian syringe to force oil into the pump so it will prime.  Do not just keep cranking!

Offline 4129R

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Re: Ignition Switch Problems
« Reply #2 on: Thursday,September 16, 2021, 09:54:31 AM »
Take your switch and key to a locksmith ands they can sort you.  Make sure you lube the ignition switch.  I use dielectric grease on the contacts (not too much).

Digital voltmeters are amazing things but they will "smell" a voltage across the dirtiest, vilest connections imaginable.  Use a 12v test light with an incandescent bulb.  This applies a load to the circuit giving a truer picture of what's up.

How much cranking did you do?  I crank for 10 second intervals, no more than 4 or 5 times.  If there is still no oil pressure, I would remove the oil pump and pack it with vasoline (I ALWAYS do this when rebuilding an engine).  Can't remove the pump?   Remove the filter and use a large veterinarian syringe to force oil into the pump so it will prime.  Do not just keep cranking!

I primed the pump and filled the oil filter before filling the sump with new oil.

I will try priming the pump again tomorrow, that worked last time on 2520R.

I will seek a locksmith with my working key profiles and locks without keys soon, but the old locksmiths whom you could trust to know their job, have been mostly replaced by key bars who can only copy keys, and not build locks.

Offline 4129R

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Re: Ignition Switch Problems
« Reply #3 on: Saturday,September 18, 2021, 02:26:42 AM »
I have just primed the 5 star into 4 housing with Vaseline, filled the oil pump to the brim, put oil in the holes on the block side until it comes out, so here's hoping when the battery is charged, I get a reading on the oil pump quite quickly. 
« Last Edit: Saturday,September 18, 2021, 04:21:40 AM by 4129R »

Offline 4129R

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Re: Ignition Switch Problems
« Reply #4 on: Saturday,September 18, 2021, 07:18:30 AM »
3rd time lucky. 1st time, primed with oil, no good.

2nd time primed with Vaseline, no good, I even swapped oil pressure gauges to see if it was faulty.

3rd time, primed with Vaseline, with jumper leads from my Land Cruiser with its engine running, it took 3 x 8 second turns on the ignition lock, and eventually it got up to a decent oil pressure just on the starter.

Tomorrow, I check the timing, the spark, and try to get the engine running. This car has been off the road for a very long time, so it is quite a milestone in this car's history.

P.S. For those of you who have Lotus Ford TC engines, you can prime the oil pump with Vaseline, in situ, by unscrewing the plate held on with 3 x 7/16" headed bolts. You don't need to take the whole pump and filter off. But before you fit the filter to the pump during a rebuild, fill it up with oil, it takes quite a lot.

« Last Edit: Saturday,September 18, 2021, 07:32:56 AM by 4129R »

Offline BDA

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Re: Ignition Switch Problems
« Reply #5 on: Saturday,September 18, 2021, 07:29:00 AM »
Congratulations!!  :pirate:   :beerchug:   :BEER3:

Offline dakazman

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Re: Ignition Switch Problems
« Reply #6 on: Saturday,September 18, 2021, 08:21:52 AM »
    :I-agree: :beerchug: 

   Congratulations
Dakazman