What wire is knocked loose? 73 240 ignition

[MikeZcar]

My son's 73 240 has not had instrument lights in a while, he's too busy running the wheels off it to look, till last night, across town in a dark parking lot. That's the same day my 103 to 104 fever of 3 days broke on this lovely flu I've had a week. Really didn't want to go look and don't want him (or me) to waste money on a wrecker and I'm still sick, but better. Anyway,,,,,,,,,,,,,,,,,,,,,,,

No drawing, no print and no energy. He layed on drivers floor, probably "giggling" wires under the dash till it won't start, STILL turns over but no voltage to the coil per someone with a meter. What's pulled loose? What color? Ideas? Thoughts?

Thanks in advance, Mike

[beandip]

Has he been messing around under the hood by chance? If he has disconnected the wire that goes from the tach . The ignition wont fire. not knowing what was done to the car it is hard to guess. Look around the ignition coil and see if there is a wire pulled loose there. Hope you are feeling better. This is a lot of car for a teen. I hope he keeps the shinny side up. Gary

[SteveJ]

My son's 73 240 has not had instrument lights in a while, he's too busy running the wheels off it to look, till last night, across town in a dark parking lot. That's the same day my 103 to 104 fever of 3 days broke on this lovely flu I've had a week. Really didn't want to go look and don't want him (or me) to waste money on a wrecker and I'm still sick, but better. Anyway,,,,,,,,,,,,,,,,,,,,,,,

No drawing, no print and no energy. He layed on drivers floor, probably "giggling" wires under the dash till it won't start, STILL turns over but no voltage to the coil per someone with a meter. What's pulled loose? What color? Ideas? Thoughts?

Thanks in advance, Mike

I looked at the wiring diagram and the instrument harness diagram from the factory service manual. As Beandip said, if the wire was pulled loose from the tach, the car will not run, and it won't have voltage at the coil.

The wires of interest are a black wire with a white stripe and a green wire with a white stripe. There is a connector to the tach under the dash. If this came off, the car won't start.

I'm going to try to attach a PDF file of the wiring diagram and instrument harness pages. Hopefully these will help with the diagnosis.

[EScanlon]

Time out:

There's a big possibility for confusion here.

The Tach Connector behind the dash wouldn't "just" come loose, it takes a healthy pull even when you ARE trying to disconnect it. But, since this is where the "giggling" was happening, it may also be a case of a disconnected wire at the ignition switch, or both.

The wires that Beandip is referring to, while they do come from the tach, it is at their other end, in the engine compartment where they connect to the coil, that Gary points to. That's where the Black/White and Green/White wire are separated. Under the dash, they are part of the same connector, along with the Green and Black wires which power the Tach.

2¢

E

[MikeZcar]

Well the flu took a week from me and I usually don't let stuff keep me from working but this was killer!! Back to the car today with a good meter, suspect he was around tach so thanks for heads up. May have already been a problem up under the dash since no instrument lights. If he can't get it going any permanent damage running a hot wire to the coil long enough (ten minutes) to drive it home?

Thanks for the replies, Mike

[Arne]

If he can't get it going any permanent damage running a hot wire to the coil long enough (ten minutes) to drive it home?

No. My yellow car came to me that way.

[EScanlon]

That's the "standard" hot wire method. Positive side of the battery to the coil +, quick short across the starter terminals and as long as the battery is working it should start and run. This works even with the E12-80 mod. All you are circumventing is the ignition circuitry and the car's electrical.

The only problem you would have is if the fusible link is the culprit, then you won't have brake lamps or any other electrical functions. However, since the starter DOES turn over, that shows that that isn't the case.

One CRITICAL note for further posts: while this is the "standard" hot-wire, let's not get into how easy it is to do it on a Z, nor how to circumvent defeat or alarm mechanisms ... Loose Lips Sink Ships!

E