Changing a 91 Q45 Ignition switch

[Joe North]

Hi everyone!! I have found the problem with my 91 Q45 thanks to all your help. I have to change an ignition switch. I have never changed an ignition switch before. Does anyone have a diagram or info. Thank you in advance. There is a $60. switch and a $300. system. I hope I only need a switch. Please advise.

[timatt]

What are your symptoms? I got my '91Q real cheap because the previous owner couldn't turn the ignition far enough to get the key out. I fiddled with it enough to get it out, then I shot graphite in the key-hole. It has worked perfectly ever since.

timatt

[JoeNorth]

Hi timatt, I was jiggling the key for about 2 weeks and it would catch. It no longer catches. I replaced the blue relay but that didn't do it. So I wanted to check the switch. When I was in the switch jiggling mode it would start on the first contact. Please advise. Thank you Joe North

[timatt]

Well OK. It kind of looks like the problem with my ignition was different from the problem you have with yours. You can take the cover off your ignition column quite easily. I think that there are two screws holding the top half and bottom half together. Once you remove these screws you should be able to see how to remove the electrical switch itself.

timatt

[Joe North]

Hi timatt, I got the cover off but it looks a little confusing to me.Is there a way of testing with the 5 wires that are soldered to the switch.? Thank you joe north

[Q451990]

From my notes, it looks like the black/green and black/yellow wires should show 12V during starting. Your color codes may be different, but I think they'll be the same.

Heath

[Joe North]

Thank you Heath! Does this mean if I cross the black wire with either the green or yellow or blue. I bypass the switch? Would the car start? I assume the black wire is the ground. If I had a jumper wire this would tell me for sure its the switch. I don't want to burn anything further out would you know what wire I should cross with the black? Thank you Joe N

[Q451990]

Does this mean if I cross the black wire with either the green or yellow or blue. I bypass the switch? Would the car start? I assume the black wire is the ground. If I had a jumper wire this would tell me for sure its the switch. I don't want to burn anything further out would you know what wire I should cross with the black? Thank you Joe N

Don't do that!!!! The switch is grounded to the chassis, so what you're suggesting will cause a short and at a minimum burn up a fuse. All of the solder joints on the switch are feeding 12V to something.

The only way that I would recommend testing for it is to check for voltage at the black/green wire with the switch in the "start" position. Hint: I've found the little pin that holds the door strap (near the hinges) on to be a good point for grounding the meter - you'll need to remove the plastic cover if it's still there.

Luckily I have the cover off on my older Q, and I was able to check it a minute ago... the black/green stripe solder joint checks 0v normally, and about 10.8v while the key is in the start position and the starter is running.

Oh, and be sure the car is in "Park" while you try all of this... if it isn't the interlock will prevent the car from starting.

Heath

[Joe North]

Thank you Heath!! I thought so. I will use a meter to test for 12V Thanks again.