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Discussion Starter · #1 ·
So, in my previous thread (see Need Ignition Relay for 1980 ZX...) I indicated that I wasn't getting power to the mentioned accessories and from forum searchs thought that the reason was a defective Ignition Relay. I know that technically it's an "accessories relay" and has nothing to do with the engine running but Nissan calls it an ignition relay.

@steve240Z73 was nice enough make a replacement relay from generic 30-40 amp relays, wire and appropriate connectors (thanks Steve) and I installed that yesterday. To my surprise, I sttill had the same problems. Sometimes the accessories have power in the 'ACC" key postion and not in "ON" and but then not when turned from "ON" to "ACC". Then sometimes the accessorites have power in the "ON" position but not in the "ACC" position. This is the situation with both the old original relay and the new replacement so it's not the relay that's causing this.

It almost seems like there is another sticky relay somewhere in the wiring of the car. @steve240Z73 has surmised that perhaps there is a problem with the ignition switch and is researching how I might be able to diagnose if that's the case by checking continuity/voltage in wiring to the relay with a multimeter. My question to the forum is have any of you experienced this? What did you determine the cause to be? Was it the ignition switch or something else?

Specifics on car: Wife's one-owner 1980 280ZX, automatic, 93,000 miles, always garage kept.
 

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I can probably get to the diagnostics this weekend. I'll see if I can email you the wiring diagram, too.
 

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I'm on the "bad ignition switch" side.
It wouldn't surprise me, but I want to make sure he does enough to confirm the fault. The parts cannon was already fired once.
 

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I emailed @BadDog42 some diagnostics that should help us to narrow down the cause of his problems.
 

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Discussion Starter · #9 ·
OK guys, with @steve240Z73 's help we've been able to determine that it's the ignition switch that's causing my problem. As I mentioned to Steve, I'm finding it strange that this is not the lock cylinder mechanism itself but rather a rotary electrical switch that is connected to and works in conjunction with the keyed lock. This may not be a revelation to you guys but I had always thought that ignition switches were one all encompassing device and not a separate keyed lock with electrical "add on" components.

The component is rather small as evidenced by the attached photo. Well, I guess it has to be if it's going to fit inside the steering column.

Anyway, I'm going to download the Factory Service Manual to learn more about how these things work in the scheme of things but while I'm doing that can anyone tell me how big a job it is to replace one of these things. I don't have a lift and I'm not near as "wiry" as I was in my youth.
Automotive lighting Auto part Gas Household hardware Cylinder
 

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I did a little more searching. The part is available from Nissan. Switch Ignition 48750-E7705 | Courtesy Parts Yes, it's more than the Rockauto parts, but I bet it's built better.
I also looked through the FSM. I forgot to look at the ST section. You have to remove the lower trim panel and the bottom of the clamshell on the steering column. Then you can pull the bolts that hold the steering column in place. That should let it droop down enough to get a small screwdriver around back.
Font Parallel Auto part Circle Diagram

I recommend pulling the negative cable on the battery before doing this.
 

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Discussion Starter · #11 ·
I did a little more searching. The part is available from Nissan. Switch Ignition 48750-E7705 | Courtesy Parts Yes, it's more than the Rockauto parts, but I bet it's built better.
I also looked through the FSM. I forgot to look at the ST section. You have to remove the lower trim panel and the bottom of the clamshell on the steering column. Then you can pull the bolts that hold the steering column in place. That should let it droop down enough to get a small screwdriver around back.
View attachment 112407
I recommend pulling the negative cable on the battery before doing this.
Steve: I am very surprised at just how useless the Factory Service Manual is on the subject of replacing this part. I noticed your diagram above in Section ST-Page 2. In the EL section it seems the manufacturer has taken special pains not to mention the switch or how to access or replace it. Now granted, I'm not interested in replacing the keyed lock cylinder but rather the rotary electrical switch attached to the back of the keyed lock cylinder. However, a person would think that there would be some written instuction on how to gain access to this area of the steering column. The only mention of the ignition switch is a diagram on Page 32 with no accompanying narrative, steps or instruction (see attached). Also on that page is how to get to the ignition/accessory relay on the passenger side which seems to gloss over the fact that you have to remove the glove box door and the glove box compartment itself before hiring a child with hands small enough to reach into the deepest darkest recess behind the glove box opening to use a small open end wrench to remove the two bolts holding the relay turning 1/16th of a revolution each time due to space constraints (this is assuming that you don't have a custom "stubby" 1/4" drive socket extension that clears the relay itself without bumping into the heater/AC plenum).

But it's not just the Factory Service Manual that is deficient in this area. I have a Haynes manual for this car as well as a Chilton's. The Haynes manual addresses the replacement of the steering lock mechanism which I guess could be what people have called an ignition switch for the last 100 years but that starts with removing the steering wheel and I'm not going there.

The Chilton manual recognizes the car has something called an ignition switch and indicates that you can get access to it by removing the plastic steering column cover halves. I'm going this route with your recommendation of dropping the whole column itself for accessibility reasons.

I gotta tell you working on my 1971 Buick Centurion convertible is so much easier than this. Point ignition and mechanical fuel pump. If it doesn't start it's either fuel or spark.
 

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Keep in mind that the FSM was for the dealers to maintain the cars. It took over 40 years for that part to fail. It wasn't something the dealers would encounter unless repairing damage on a stolen vehicle.
When I was working on an 82 280ZX turbo, the upper part of the clamshell was too much of a PITA to remove. While you can access the electrical connector without letting the steering wheel hang down, I'm doubting you can get a screwdriver back there. There are just two screws to remove to replace the module, but you might add some new cuss words to your vocabulary. If you pull the knee panel and the two bolts that I indicated, the steering column should sag down enough to access the back of the switch.
Here's pretty much what it looks like. I found the photo on ZCarDepot's website.
Crankset Nickel Bicycle part Font Rim

You can see the screws on the back side.
 

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Discussion Starter · #13 ·
Keep in mind that the FSM was for the dealers to maintain the cars. It took over 40 years for that part to fail. It wasn't something the dealers would encounter unless repairing damage on a stolen vehicle.
When I was working on an 82 280ZX turbo, the upper part of the clamshell was too much of a PITA to remove. While you can access the electrical connector without letting the steering wheel hang down, I'm doubting you can get a screwdriver back there. There are just two screws to remove to replace the module, but you might add some new cuss words to your vocabulary. If you pull the knee panel and the two bolts that I indicated, the steering column should sag down enough to access the back of the switch.
Here's pretty much what it looks like. I found the photo on ZCarDepot's website.
View attachment 112410
You can see the screws on the back side.
Steve:
Well, I'm learning something new every day. Today it's that what I used to call an ignition switch is really what is now called a Steering Lock Mechanism (SLM) that has a rotary electrical switch affixed to it. This is probably nothing new to people who have had to get inside steering columns before, but a revelation for me. I think locking steering columns have been mandated by federal law since the 1968 model year and I suspect that all keyed SLMs and rotary electrical switchs have been designed this way since (at least those that don't have push button start). I just wasn't aware of it. Shows how old I am.

I have a rotary electrical switch (i.e. what post 1968 is now called an ignition switch) on order that is supposed to arrive tomorrow. Maybe tomorrow I will learn some of those words you said I might.
 

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You don't need to be a contortionist to get that part off once you have the plastic covers removed. But be careful as the plastic can be brittle and easily broken. Worst case, as you can see in the Z Car Depot photo above, the whole assembly can be easily removed from the steering column with the single electrical connector being removed as well. It's polarized so no worry about reconnection later. Removing the whole assembly allows you easy access to the rear switch screws. I only know this because I've disassembled my whole car for this restoration project.
 

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Discussion Starter · #16 ·
Well, got the switch installed and now everything works as it should. As @steve240Z73 mentioned above, removing the steering column attachment bolts allows a couple of inches of drop and the shell covers separate to give you enough room to get a short 'stubby" phillips head screwdriver behind the keyed Steering Lock Mechanism (SLM) to remove the rotary switch. @OldSchoolZGuy mentioned removing the whole SLM if a person had to. Man, I would not want to ever do that. The SLM (for security purposes it's said) is attached to the steering column with two regular screws and two "self-shearing" screws. The self-shearing screws break off upon assembly leaving no head with which to remove them. Once again, the FSM mentions nothing about how remove them other than "1. Break self-shear type screws with drill or other appropriate tool. 2. Remove screws and dismount steering lock". Way, way, way oversimplification of what really must be done. My Haynes manual devotes a large paragraph to the process which I will distill here to 1) very carefully center punch and drill a small hole in the center of the screw, and 2) using an appropriate sized EZ-out remove the screw. With the diameter of the screws this could be a real challenge. I wonder if a person could just grind them flush in order to separated the halves of lock assembley. Lucklily I didn't have to replace the SLM and now all is well except for what I describe below.

While working on this "accessories problem" I've discovered that the car has a substantial leak from the power steer gearbox output shaft. See my separate posting on this subject.

Again, thanks to all who helped me on this project.
 

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For the shear screws, I use a dremel or cold chisel to cut a groove in the head to remove it with a screw driver. I had to do that a few months back when the steering lock mechanism in my 73 was misbehaving. I actually had a replacement unit on hand for about 9 years.

I'm glad you got the switch taken care of.
 

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Discussion Starter · #18 ·
For the shear screws, I use a dremel or cold chisel to cut a groove in the head to remove it with a screw driver. I had to do that a few months back when the steering lock mechanism in my 73 was misbehaving. I actually had a replacement unit on hand for about 9 years.

I'm glad you got the switch taken care of.
Steve: That's a really innovative solution - and much simpler than drilling the center of the screws. I'll have to remember this if I ever have the lock misbehave.
 

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I learned that from a good friend.
 
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