Replaced Ignition Swich car won't start

[Roger59]

I have a 91 coupe and I have removed and cleaned the ignition switch once, due to car switching off going over bumps this was a few years ago and no issues. Recently I turn key and car does not turn over on initial try but will start a few tries later. So now after having replaced the switch and key would not turn and radio and HVAC have power and won't shut off. So I removed and re-installed now key turns now key turns but no power to radio and HVAC. So I replaced with old switch and same thing. I have checked the ignition fuse in the drivers compartment it was good and I have also I have replaced the main relay as a PM, not sure where to look after that?

 

[warrenw]

Roger. Did you check the main relay?


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[Miner]

If you get to the wiki and download the service manual, troubleshooting for the ign switch is very straightforward. If the engine doesn’t crank, or things like the radio or dash don’t light, the focus on the battery connection or ign switch. The main relay comes into play if the engine cranks but intermittently starts.

 

[drew]

Make sure the switch is indexed properly.

You can keep the switch plugged in, but not screwed in on the key lock. Give it a spin after taking if off the key lock...

 

[Roger59]

Roger. Did you check the main relay?

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I did not check it as i replaced the main relay as a PM a few months ago. When I first installed the power was on and the only way to shut off was unplug switch from car, do you think it might have done something to main relay?

 

[Roger59]

If you get to the wiki and download the service manual, troubleshooting for the ign switch is very straightforward. If the engine doesn’t crank, or things like the radio or dash don’t light, the focus on the battery connection or ign switch. The main relay comes into play if the engine cranks but intermittently starts.

I do have the service manual for 91 to 96 downloaded and I also own the later edition for the 97 to 2005. What confuses me in the service manual the 3rd step in removal "insert key in turn to 0 position". It appears to me that the "0" is the first one and does not need the key turned?
Thanks for your input

 

[Roger59]

Make sure the switch is indexed properly.

You can keep the switch plugged in, but not screwed in on the key lock. Give it a spin after taking if off the key lock...

Thanks for this I have tried indexing the switch, but I always unplugged it worried about causing an issue or something, so I will try it plugged in and hopefully I can get it indexed properly. I will see what I can find out with it still plugged in.
So I found that no matter what position I installed the switch there was no power. I also confirmed that the switch was in the "0"position with a continuity test.

 

[Old Guy]

I had a little trouble following this; but, I gather that you removed your original repaired switch, installed a new switch which didn't work and then replaced it with the original switch which now doesn't work - correct?

First off, if the starter motor does not turn over, that is not a main EFI relay problem. It is a starter interlock problem (clutch switch), ignition switch, bad battery connections or the actual starter. Given the other problems you describe, this does seem like an ignition switch problem. I line up behind @drew on this and expect that you have a switch indexing problem. Perhaps 3 -4 years ago there was a thread started by a member who could not get their new ignition switch to install correctly. The problem was that as assembled from the factory, the switch internals were not in the 0 (locked) position. As I recall, re indexing the switch is as easy as sticking a screwdriver into the engaging slot on the internal mechanism and rotating the switch to get it correctly indexed.

If you can't find that old thread, I have my refurbished original ignition switch wrapped up out in the garage and I can dig it out and take a picture showing the correct indexing of the switch internals. The other option is if you have an electrical continuity tester, the service manual has a little matrix diagram (page 23-72) showing which terminals of the switch are connected together in each of the switch positions. You can use the diagram and the tester to figure out what position the switch is currently in and then rotate the internals to get to the 0 position. Confirm by using the tester to check that none of the switch terminals are interconnected. Make sure that the ignition key / lock cylinder is in the 0 (locked) position and with the switch in the 0 position it should fit correctly onto the back of the lock cylinder.

Let me know if you need the switch photo and I will try and oblige. May take a day or two.

Be cautious about rotating the switch internals with it plugged into the car wiring harness. The starter motor should not engage unless you are one of the owners who has by-passed their clutch interlock in which case you may get a surprise. I prefer to do my switch testing using a continuity tester with the switch out of the car.

 

[Roger59]

Today I tested both ways and had confirmed via continuity test that switch was in correct position. As I recall the first time I inserted key I had power but I could not turn the key further. Also the power to HVAC and radio stayed on with no key.
Presently the switch is installed in the "0" position confirmed and no power to HVAC and radio in any of the three positions.
The switch test's out good like the manual says and when installed no power to HVAC and radio and no sign of any life in the starter.

 

[drew]

I'm wondering if an mis indexed switch would cause a fuse to blow, check to be sure.

Are you pushing in the clutch pedal (MT) or in Park (AT) while turning switch to start?

Is the old switch giving the same behavior?

 

[Old Guy]

Mystery!

You said you checked the ignition fuse in the driver's compartment. The fuses that would blow in the event of a problem with the ignition switch are not in the passenger compartment fuse box. There are 3 fuses that can affect ignition switch operation, they are #9 and #12 which are in the main fuse box in the engine compartment and #29 which is in the relay box in the front compartment. These are all big screw in PAL style fuses. Check those to make sure that they are all intact.

If the fuses are good, I am wondering if the little piece that sticks out the back of the lock cylinder assembly and fits into the switch has been damaged or failed. With the switch removed from the lock assembly, can you fit your finger up into the back of the lock assembly to feel that little piece that engages the switch. You might be able to use a small inspection mirror to see the back of the lock assembly, although from what I remember from replacing my switch I think that probably will not work. With your finger in place or using the mirror, turn the key in the lock cylinder to confirm that the piece that fits into the switch is also turning. Do this for the 0, I, II and III positions on the switch. If the piece is missing or it is not turning in each of the key positions then you have a lock mechanism problem.

If the lock mechanism appears to be working, then I suggest that you do what I previously recommended against. Connect the switch to the wire harness (make sure it is in position 0) and use a screwdriver to rotate it to the I position (accessory). This should allow you to operate the radio. If it does then rotate it to the II position (run) and you should see the dash indicator light illuminate and the fuel pump should go through its prime cycle. If all that checks out, then the vehicle electric system is OK and you have some kind of problem with the switch and the lock mechanism. If that test doesn't check out and the fuses are OK, then two things to check
- examine the plug on the body side of the wiring harness that the switch plugs into. Make sure that the electrical terminals inside the plastic plug body have not come loose and are pushing out the back of the plug body when you insert the plug from the switch.
- double check to make sure that your battery post connections are OK and that the battery is good.

The connection between the battery and the ignition switch is pretty direct. If the fuses are good and the battery / battery connections are good you should be getting power to the switch. If you have tested the switch according to the service manual and it works correctly in all positions then the problem(s) must be downstream of the switch.

As a thought, did the car ever have an aftermarket security system installed? Is it possible that some of that wiring has failed causing a problem?

 

[Roger59]

After trying to explain my dilemma I am thinking about fuses, I was unsure which ones to check, last night I pulled clock fuse thinking that when I have done this in the past I had to reset the radio as it lost the stations. Unfortunately the fuse was intact. So thanks again for a good direction to go looking.
I think I have put my finger inside to feel the part that engages with the switch, I will double check that as it is just two screws to pull switch at this point. thanks again for the great leads into solving my mystery.

 

[drew]

I can't determine if you isolating the mechanical link of the electrical switch?

If not, get in the driver's seat, get a flat screwdriver, plug the switch into the vehicle harness, and make the switch turn with the screwdriver.

 

[Roger59]

I can't determine if you isolating the mechanical link of the electrical switch?

If not, get in the driver's seat, get a flat screwdriver, plug the switch into the vehicle harness, and make the switch turn with the screwdriver.

I just went and tried the switch with a screwdriver and nothing in all three positions. In the cylinder I can feel a metal protrusion with slots on the sides which I assume fits inside the plastic part of the switch. So now I just have to find which fuse I blew hopefully. Thanks for the input.

 

[Roger59]

So with everybody's help I found fuse #29 (50amp) in the front compartment and in the engine compartment labeld IGN SW (b) ? (30amp) fuse both failed continuity test even though visually looked good. So I will source a couple of new ones and hopefully I will have power to the ignition switch. So today I picked up the two fuses and the car started. What a great feeling Thanks again to all for the inputs and help in trouble shooting my dilemma.
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