Dead Tach, Gauges and turn signals

[Herb]

I was driving my 72 240z home yesterday when my tach dropped to zero as did the fuel tank , temp, and oil pressure gauges. Turn signals also packed it in at the same time. I also think that the car started running a little more rough (but maybe that was my imagination as I was peeved at the elect system) Now the car won't start!. Any help in troubleshooting this one would be greatly appreciated

[Schev]

This may sound like a stupid solution, but did you try recharging your battery entirely?

[EScanlon]

Please define "Won't Start!":

You turn the key in the ignition lock

you hear the click of the accessory relay on the passenger kick panel,

you turn the key further and you hear a louder click coming from the engine bay area

and you can hear the starter engaging

and the engine turns over

slowly

normally

and then does / does not kick over, not at all or sometimes.


However, since you mention that all the lights on the dash went out, I'm going to presume that you were driving in daylight and as such did not notice if your lights went out, or didn't have them on to notice, that the car ran on but seemed different and that now it won't start....check the fusible link between the battery and the starter.

If that fusible link goes out, the car simply has no connection to the battery. The engine, if it was running, will continue to run, just as if you had used a starter trigger. I've not verified the second, but according to the schematic that's what should happen.

Enrique

[Herb]

The Battery is good. When I turn the ignition the accessory relay clicks on the passenger kick panel but that is it. The tail lights and marker lights are working the headlights aren't. Where is the fusible link? The only thing between the battery and starter are the power and ground cables.
Appreciate the help

[bav]

Herb,
what year is YOUR Z?!?!

Brian

[Bambikiller240]

The Battery is good. When I turn the ignition the accessory relay clicks on the passenger kick panel but that is it. The tail lights and marker lights are working the headlights aren't. Where is the fusible link? The only thing between the battery and starter are the power and ground cables.
Appreciate the help

Just because the relay clicks, it does not mean that your battery is OK, it takes a lot more power to drive the starter than it does to activate the relays. When battery cable connections are corroded, or a battery is partially drained it is common for the relays to click yet the starter not engage.

But anyway the fusible link is the smaller wire that bridges between the starter and the wiring harness. It has a ring terminal on one end which is attached to the starter, and a plastic (nylon? whatever) clip that plugs into the wiring harness on the other end. It's about 6" long. (approx.)

[Bambikiller240]

Herb,
what year is YOUR Z?!?!

Brian

See Post #1

[wal280z]

But anyway the fusible link is the smaller wire that bridges between the starter and the wiring harness. It has a ring terminal on one end which is attached to the starter, and a plastic (nylon? whatever) clip that plugs into the wiring harness on the other end. It's about 6" long. (approx.)

Banzai Motorworks has a good picture of it in thier online catalog. Click on 'Customer Requests' it is the 3rd picture down, labeled 'E-28'

Wayne

[EScanlon]

Just because the relay clicks, it does not mean that your battery is OK, it takes a lot more power to drive the starter than it does to activate the relays. When battery cable connections are corroded, or a battery is partially drained it is common for the relays to click yet the starter not engage.

This deserves repeating.

Too many times people go off and "fix" several other items that had nothing to do with THIS basic problem.

But anyway the fusible link is the smaller wire that bridges between the starter and the wiring harness. It has a ring terminal on one end which is attached to the starter, and a plastic (nylon? whatever) clip that plugs into the wiring harness on the other end. It's about 6" long. (approx.)

However, that you get ANY click at all from the solenoids, says that the fusible link is at least getting SOME power through, if that's possible. If the fusible link has blown, there is NO connection between the car circuitry and the Battery other than the Negative Ground. Without the fusible link, the car is simply.....dead in the water. You won't have ANY electrical activity at all anywhere...except for any added circuitry that connects directly through to the battery. This is part of the reason you need to be real careful when adding "circuits" to your electrical system. Plug into the car's wiring incorrectly and you might find your lights go on when you start your car, or your wipers only work when you have the brake lights on or some other nightmare.

I'm more concerned in that you mention you can't find the fusible link.

Never replace a fusible link with a plain piece of wire.

A fusible link is ... A FUSE. It's designed to blow before you incur damage. Replacing it with a wire is like coming up from a deep sea scuba dive while holding your breath!

2¢
Enrique

[bav]

I found the Fusible link and it appears that a previous owner has "modified" it two wires soldered into the plastic connector... Great... I'm in process of getting a new one but I still have the problem of Dead Tach, Headlights, panel lights. Any idea where to start on this?
Thanks for all the input

[eulb1]

I had the dead gauges problem the other day. I found the “Flasher” fuse in the fuse block was bad. The fuse looked intact, but when I checked it with a tester it only had power on one end. I replaced the fuse and my gauges work again.

[EScanlon]

First get that link fixed, then see what is still out.

Hard to even hazard a guess as to what may have fried or ...?

Doing fuse checks is one way, but remember, you don't have ANY juice going to the car at all without that link. If you do, then you have more things to check and correct as that shouldn't be happening.

One good thing to check right now is that all the fuses in the fuse box are making contact. Remove each one and do a continuity check to it REMOVED from the fuse box. Many times people report that the fuse LOOKED ok, but in fact failed a simple continuity check.

As a suggestion, don't get frustrated trying to "fix" it while waiting for the part. Performing other "fixes" when you can't tell if in fact you are FIXING, may exacerbate the problem further.

Just 2¢
Enrique

[Herb]

Jeez I feel like an idiot. I checked all the fuses when the car crapped out and they all looked good. However once I started looking closer I found that the fuse that protects the gauges was faulty and had failed near the end. SO the gauges now work. Now I need to figure what happened to the headlights!!!
Thanks for all the help

[Bambikiller240]

Pull ALL the fuses out, and check them with a Ohm-meter. "Looks good" does mean squat. (see post #12) Most of us have at one time or another been fooled by the "looks good" issue.