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I wanted to post a Thank You to all those who have contributed their expertise about trouble shooting the Dead Light Syndrome on Z Cars.

You know who you are.   I'll share my experience - Hopefully it will help someone else.


I have gradually been losing electrical component functions. Last week she stopped charging while cruising around.  Voltage gauge gradually dropped to 10-8-6 volts.. Thankfully I have an Optima Yellow top and was able to limp back to the shop. This car has voltage regulator separate from the alternator, under the fusible link/beer can holder. With battery disconnected, I was able to confirm alternator was not charging -  by cleaning the 7pin connector at the regulator - 1 pin showed only minor corrosion; This was enough to regain charging, and has been charging/starting since. I regained tach/gauges also.


Now, on to the dead headlights + hi beam indicator  / exterior signals + dash indicators / emergency flashers & brake lights - So, undrivable.


Following the suggested troubleshooting recommendations in the forum, I confirmed continuity and cleaned all fusible links and fuses, all good - some minor overheating indicated on front right (heaviest)  fusible link.    Test light confirmed good power at all fusible links and fuses except the headlight fuses.


I moved on to checking grounds, dremmel wire brushed license plate and headlight ground connections, did not look too great- paint from body shop on connectors, especially at the rear, reconnected with some dielectric grease.


Then on to the flasher unit above hood release, found that the 2pin L-Shaped plug had become disconnected.


On to headlight combination switch, removed shroud,

(this reminds me of the Japanese sense of humor - 6 screws - 4 different types / take note of what goes where)

Found out why my horn doesn't work - broken plastic connector on thin brass brass horn connector. Taped it up, out of the way.

Searched around for loose ground, or other obvious issues - none seen.

Sprayed some Deoxit chem spray around the hi-beam lever, turn signal cancel mechanism, and in and around the little circuit board in the pictures below...

As I was test probing for power around the Green - Red & White Red Wires attached to it, and moving hi-beam lever, cycling on/off the headlights

VIOLA!?!!?!?     On came my Headlights, Low&Hi Beams! & Signals!! Interior indicators too!?


So with this progress,   I remember reading that the 4 tabs on this little box can be carefully straightened upwards to access the parts inside.

So with battery once again disconnected, I opened it up to find an old school switch mechanism, surprisingly with NO visible corrosion or signs or arcing or overheating. Rotating the headlight switch moves two little nipple like pieces - I thought i would run a bit of sandclothe over them (don't do this) I thought I had broken the little tit off!  But then realized that they are little caps, supported by tiny little springs. I very slightly pulled on the springs to provide a bit more pressure on the little brass contact levers also contained within, sprayed some more Deoxit around and cleaned all the parts with a cuetip. Reattached the small brass tabs -


I know - long winded // Really just a sincere   Thank You for all the guidance.


PS:   Now my Volt gauge doesn't work.    LOL - any ideas???



280 MultiFunction Switch 1.jpg

280 Multifunction Switch 3.jpg

280 Multifuntion Switch 2.jpg

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The voltmeter wiring is really pretty simple.  What year/model is the car?  Has the voltmeter EVER worked for you; and if so, when did it stop working?  


If a PO replaced ammeter with voltmeter, they may not have done it correctly.


An easy diagnostic is to remove the gauge, and hook it directly to a good battery.  If no reading, then the problem is the gauge.  If it does read correctly, then you'll know the problem is in the wiring somewhere.  A lot of the multiplug connectors in the various harnesses can easily get corroded and/or loose and cause issues like you're experiencing with the voltmeter.  Good luck with it.

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  • 2 weeks later...
  • 3 weeks later...
On 11/23/2019 at 10:17 PM, 280zzzzz said:

She is an Aug 76 serial number

I've owned it since 78ish It has always work until now.

I do suspect the voltage reg 7pin connector -

Time to get back in there...


Thanks for the comments.


If you're not concerned about maintaining the OEM wiring configuration, you can pull your input for the voltmeter from any good 12V circuit in the system (assuming that the voltmeter is working correctly).


If your voltage regulator is not working correctly, that's another issue altogether, and you probably have bigger problems than a non-functioning voltmeter....


@ELbrown33, you're going to need to be more specific with your question.  If you need help with a specific electrical issue, you may want to start a new thread, to avoid confusion with the ongoing discussion initiated by the original poster on this thread.

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