Turn Signal Went Up In SMoke

[Marty Rogan]

I finally got time to get the blue '70 out of storage and went for a drive on Sunday. On the way back, I turned on the left turn signal and smoke started coming out of the steering column. I shut everything off right away and it stopped smoking.

Last night I took the cover off the steering column. None of the wires looked melted. I am guessing something inside must have fried. Anybody have that happen to them?

I remembered that I bought a brand new turn signal and headlight combo switch years ago as spares. After I dug out the spare and removed the original, I started noticing that they were different. The original has two large plugs, one with 3 prongs, the other has 5. On the new one the two plugs both have 3 prongs. One of the plugs is also much narrower and has a wire loom that is about twice as long as the original. Also, it does not have the copper contact arm that I believe contacts the horn ring. Check out the pictures below. The original is on the right and the new one on the left.

So I checked the parts CD. The diagram shows the turn signal as being item 2 or 3. Item 2 is described as: "25540-N3605 Comp Switch Turn Signal Dimmer". Item 3 is described as" "25545-N3600 Assy Unit Turn Signal". Neither listing shows any dates on them. My car was built 6/70 by the way. Does anyone know which is the correct part number for the turn signal switch? It is strange that they would show 2 listings for the same part, but no differences in dates they were used. Any body got a known good one that they would like to sell?

I am guessing the new one that I have is from a later model car. I have only had 240Z's so I can't tell what it came from.

Thanks,

Marty

Edited June 28, 2011 by Marty Rogan

[Arne]

I might still have a good spare early switch or two, Marty. Might not be able to check until Friday, however.

[Marty Rogan]

Thanks Arne. Let me know what you have when you get a chance.

[grantf]

that's funny I had the same thing happen last week. A burt electrcal smell and smoke out the steering colum. I have not noticed anything amiss though. really spooking me.

[Marty Rogan]

that's funny I had the same thing happen last week. A burt electrcal smell and smoke out the steering colum. I have not noticed anything amiss though. really spooking me.

You can be sure one thing; it is not going to get better! Have a look at that soon.

[EScanlon]

Sadly, the documentation in the parts manual, whether in Microfiche, CD or book leaves a lot of questions to be answered. It's not uncommon for there to be obvious omissions and mis-directions to occur.

As far as the turn signal assembly, take care that you receive one that not only has the same connectors for the wiring, but that the main body mount is the same as the one you are replacing. This is because there WERE variations on the different turn signal bodies that many are not aware of. You can usually get the Combination Switch to work, connect and mate up to the replacement turn signal assembly, but there are situations where there are differences in how things line up. Recently a friend of mine replaced his, only to have to modify the "clam cover" (the plastic surround) because the turn signal stalk rubbed against it and was no longer centered within it's opening. The connectors matched, but the body was different. He had received the new assembly as an exchange when he had his original turn signal assembly "refurbished". While the refurbisher simply sent him another turn signal assembly, the replacement piece was not an exact replacement.

As you can see from the pictures that Marty posted, one shows the nylon block for the Horn Swipe, the other doesn't, nor a place to mount it to.

FWIW

E

Edited June 28, 2011 by EScanlon

[Marty Rogan]

So... Does anyone know which of the P/N's I listed is the correct one for the turn signal switch?

Thanks,

Marty

[Marty Rogan]

Update on the turn signal switch.

A local Z buddy of mine had a switch that has the same connectors, except that one of them had a longer wire loom than the original. This website:http://www.new-datsun-parts.com/240Z-parts-electrical.html identifies it as being for cars built 9/71 - 7/73.

Last night I hooked it up and everything with it functioned correctly. I drove the car to work today. Now the temp gauge and the oil pressure gauge are not working. Both were working prperly before the switch was put in. Could this be some weird coincidence? I could not believe that the turn signal switch had any connection with the other gauges.

Marty

Edited July 7, 2011 by Marty Rogan

[Zs-ondabrain]

It doesn't. It sounds more like an alternator surge that may have messed with them. The other possibility is what ever fuse powers both gauges and the switch????

I would suggest looking at the power source (fuses) first. The 3605 sounds like the full COMPlete unit and the 3600 sounds like just the mechanicals but not the wiring or electrical.... Just a guess though. The later, longer wired switch can easily be used to replace your stock one, without any issues other than looping the wire and making it fit in the clamshell.

I would also suggest an electronic Flasher to minimize resistance. If you can find no burnt areas on the switch, it could have been grease on the contact that finally let the smoke out of the jar, so to speak.

Dave

Edited July 8, 2011 by EScanlon
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[Marty Rogan]

It doesn't. It sounds more like an alternator surge that may have messed with them. The other possibility is what ever fuse powers both gauges and the switch????

I would suggest looking at the power source (fuses) first. The 3605 sounds like the full COMPlete unit and the 3600 sounds like just the mechanicals but not the wiring or electrical.... Just a guess though. The later, longer wired switch can easily be used to replace your stock one, without any issues other than looping the wire and making it fit in the clamshell.

I would also suggest an electronic Flasher to minimize resistance. If you can find no burnt areas on the switch, it could have been grease on the contact that finally let the smoke out of the jar, so to speak.

Dave

I checked the fuses and none of them are blown. It is kinda weird that the fuse box cover does not list which one goes to the gauges though.

Your surge theory may fit. On the way home from work, when I hit 70 on the highway, the gauges started working again. Now they seem to cycle on and off. I may have accidentally left the key in the on position when I was plugging in the switch. Maybe that "shocked" the gauges?? So, do you fix gauges too? I'll have to send you a PM about the original switch.

Are electronic flashers available at a common parts store, or where would I get one?

Thanks,

Marty

Edited July 8, 2011 by EScanlon
Removed Ad from quote

[grantf]

I had the exact same problem on my 77. Still not sure what caused it. I took apart the switch, cleaned the contacts and pulled the little spring that puts tension on the copper contact thingy to give it a better contact. My turn signals work great now. But this was after I took apart the high beam low beam switch, I mistakenly thought this was the culprit and in the process the contact plate crumbled apart :tapemouth Now I need a new one. Dave? can you help?