Need Help with Ignition Problem
 

the engine starts right up but won't stop when I turn off the key.
I have to pull out the green fuse in the engine compartment to stop it.
...and the battery will drain if I don't disconnect the negative terminal.
...when I touch the connector to the negative battery post the main relay will click.
...this is with the key off, so there really shouldn't be any current flowing.

Easy test, disconnect the ignition harnesses with the car running to pinpoint if this is a bad key cylinder. They do go bad.

Is there any aftermarket wiring in the car, or anyone recently done work under the dash? A few years ago there was a strange issue similar to this, I think ultimately someone had accidentally transposed two non-keyed connectors in the driver’s kick area when doing some work.

Thanks for the response.
I don't see how it can be the ignition switch --because i had put a new on in (the electrical part of the switch) which had the same result --i.e. the engine would still run after turning off the switch.
How would I go about testing the main relay to see if it is working ok.?

That’s good information to know. To be clear, did you install a brand new part, or new to the car part? We really don’t know anything for certain without testing, so I don’t put much faith in parts swapping. Fortunately, we can test this at the same time we test the main relay.

Two ways to check the main relay. First, the “idiot test”. Simply put your hand on the relay and listen; you will feel and hear a click when the relay engages/disengages. The relay should turn on with key to on position, and off when key off. The real way to check is with a DMM. First probe the small gauge black/white and black wires, these are the coil terminals. Confirm 12V when the key is turned to on, and no voltage when key off. This will tell us the upstream control from the ignition switch is operating correctly. Moving on, check the voltage output on the large gauge black/white and black/yellow wires. Both should have output the same as above.

FSM page 50-25 or 50-28 covers main relay schematic, depending if your vehicle is a TII or not. I have attached a snip for your reference.


https://cimg9.ibsrv.net/gimg/www.rx7...2413f1b5f.jpeg


https://cimg5.ibsrv.net/gimg/www.rx7...7dc60dc14.jpeg

...the ignition switch that I tried was a new one.
...what's strange is that just touching the negative cable to the battery post will make the relay click --even though the key is not even in.

something is shorting the ignition circuit. try what daniel says and when its running unplug the connectors at the switch. otherwise something somewhere is closing the ignition circuit and without being there its really hard to diagnose.

? do I need to disconnect all four connectors --or is there just one of them that would prove the test?

Look at the schematic above, there are two IGN wires.

...i did the test with engine running and disconnecting the two connectors (labeled in diagram as IG1 and IG2)...
...the engine still kept running.

Then something else on that circuit is sticking, keeping the main relay energized.

...do you have an idea as to what test that I might do in order to trace the short down?
...should I assume that it is not the relay itself?
...Daniel suggested testing the relay with a meter on the black/white and black wires.
...but they all go out immediately wrapped into a harness.
...unless there is a connector downstream to test?

I'm sorry but without being there I can't offer much more. Trying to diagnose an electrical issue is normally a pain. Trying to do it over a forum thread is exponentially harder.

Get a circuit diagram, find everything that ties into the triggers for the main relay and start checking them.

can we make sure you're properly identifying the main relay? The connectors are within 6” of the relay body…easy access for probing and disconnecting. You can also pierce the insulation of the wiring with a sharp DMM probe tip.


https://cimg2.ibsrv.net/gimg/www.rx7...119c307c6.jpeg


I already explained how to help rule this out…if the coil terminals still have voltage with key off, you know you have an issue “upstream” on the control side. If the coil terminals do not have voltage, but you still have 12V on the relay output, you likely have an issue with the relay. If you then disconnect the relay and the car shuts off, you have confirmed the relay is internally staying latched.

Do you know where to find the FSM so you can reference the vehicle wiring schematics?

thanks....i will check the relay tomorrow.

https://cimg7.ibsrv.net/gimg/www.rx7...1d2301cba7.jpg
.that's the relay on right. ...should that jumper wire be there on the blue connector? ...purpose? ...the little white connector under the blue one has the wire clipped off?? ...anyway it looks like i have find a way to pierce the wires as I don't have sharp points on my tester wires. ...looks like it would make it easier to unfasten the coils and try to get them out of the way ---is this correct?

Jumper in the blue connector is the factory installed security relay bypass. This just means your vehicle does not have an alarm that disables the starter. Nothing to do with your issue.

if you unbolt a coil you need to ensure it remains grounded (bolt it to another location, temporarily connect to a decent sized ground wire, etc.) as they ground through the body mount.

I've had a weird problem when I wired up.an s5 alternator wrong on my s4 and it would do as described. Alternator was backfeeding to keep the ignition on.

Sorry about the delay but I had to focus on some other work.
I disconnected the coils to move it out of the way to get access to the connectors and wires.
But I couldn't figure out how to do the testing.
Should I assume that the connector with the small wires (input voltage?) should not be disconnected? -- (thinking that if I disconnect it then the voltage cannot get to the relay.)
The bottom connector shown in the picture included has 4 wires to it, the other 2 wires--which look like the smaller wires you spoke of.
For example, to test the smaller wires for 12 volts, should I probe one of the wires with a positive probe and the other with the negative probe; or should I puncture one with a probe and touch the other to a ground.
I would really appreciate a clarification as to the procedure for testing.
Thanks.
https://cimg0.ibsrv.net/gimg/www.rx7...cb70b87d81.jpg

...looks like my reply was posted just below at #18.

I'm not sure what else I can offer you.

To test that relay, the two small wires are 12v triggers. With the key off if you send 12v to one or the other the relay should click.

The 4 large wires are 2 supply and 2 outputs. 2 should have battery power and two should output 12v when the corresponding smaller wire is triggered.

...I first applied 12 volts to the trigger wires that go to the relay and the relay clicked.
...then with the multimeter I checked for 12 volts with the key on and then the key off.
...it showed voltage both with the key on and the key off.
...there shouldn't be voltage there with the key off, so something is askew upstream of the relay.
...i had checked the electrical part of the switch previously and it checked out ok. (following the diagram on the left side of the following image of the two versions.)
...is there some other possible reason why there will still be voltage going through the trigger wires to the relay when the switch is in the off position?

https://cimg6.ibsrv.net/gimg/www.rx7...b5470f49e4.jpg
? is the right side diagram of the switch a simplified version of the same thing?
...my connectors are the same as shown in the left diagram which indicated the K1 and K2 terminals (purpose?)