When I first bought my 240Z, the first relatively serious issue I noticed with my new Z-car, was a very finicky and difficult ignition switch. Fearing the worst, I began my search for a replacement ignition switch and was met with what appeared to be an inexpensive replacement although I couldn’t find any reviews on the part or the retailer. I took a chance and bought it and genuinely found it to be one of the highest quality replacement parts I have ever found for a classic car! The actual replacement process took some time, but in general my new ignition switch (and new set of keys) was back to new in no-time. If you have a similar issue and would like to replace your ignition switch, read on as this will be a quick guide to doing just that.
Recommended Replacement Ignition Switch
The replacement part I bought online at the time used to be only available from overseas retailers, but in 2018 this part is now carried by some American retailers.
The exact part I bought and now strongly recommend is available from Parts-Pros on Amazon. Note that this will fit the 240Z, 260Z, and the 280Z, and all model years within these models. This ignition switch comes with two keys.
Replacing your Ignition Switch
To reveal the ignition switch that needs replacing, you need to remove a few screws that join the top and bottom halves of the plastic housing around the steering column. The screw heads will be on the bottom. When you remove these, be sure to keep track of which hole they came from as they are different sizes.
With the ignition switch assembly exposed, simply remove the plug so that you can completely remove the old assembly once you have detached it from the steering column.
You will see the actual ignition switch is attached to the steering column with four screws. However, if it is an original ignition switch you will find that two of them are ‘shear’ bolts with no clear screw slot. This was a safety feature that prevented would-be thieves from simply detaching the switch assembly and manually picking the steering column lock. The way these work, is that it originally had a hexagonal head that would shear off after a certain amount of torque. Your replacement switch may actually come with two replacement shear bolts, but more on that later.
To remove these shear bolts, you will need a Dremel. Next you’re going to want to grab a Dremel with a cut-off attachment like this one. If you don’t already have a Dremel, I highly recommend you consider purchasing one just for this process. Not only is it pretty important for this repair, but I consider my Dremel to be one of my most useful tools. On Amazon, the Dremel 4300 offers a great package that includes a starter kit of over 40 accessories, a.k.a. you won’t need to go back to Home Depot every time you want to use the thing for a new job!
With the Dremel, simply attach a cut-off mandrel and cut a new horizontal slot across the face of the shear bolt head. It shouldn’t take much force or time, but just be careful that you do not cut into anything else as there are a lot of wires and sensitive pieces around this area. I suppose it doesn’t matter if you accidentally cut into the housing a bit as you will be replacing this shortly. Use a flat head screwdriver to remove the two shear screws now that you have cut a slot in. With all four screws removed, the switch assembly should separate into two pieces allowing you to remove it from the steering column.
At this point, simply repeat this process in reverse with your new ignition switch. One thing to look out for: make sure you have the switch oriented correctly so that the steering lock aligns. Attaching the new assembly with the four screws should be straightforward. If your replacement part comes with the two shear screws (with hexagonal heads) simply tighten until the head shears off. At this point you can plug in the electrical connection and test to make sure the new switch operates correctly. Reattach the plastic housing pieces, making sure to use the same screws for the same holes.