Is my car going to burn down or leave me stranded?

[Guest the_dj]

As I'm driving around, every once in a while the voltage suddenly drops off to 12v for a few seconds and the battery charge light on the voltage gauge comes on for a few seconds, then it goes back to normal. When it's happening, it happens maybe once every 15 seconds.

 

I haven't found a definate pattern, but I think it may only do it when the lights are on (not sure).

 

In the recent past, I had my front passenger parking light not come on (blinker worked though) and a voltmeter showed only 6 volts at the light. Since then, it somehow started working again. I also pulled all my center gauges out to make templates for printing the new faces. After I put them back in, the battery gauge itself no longer works, and the clock backlight doesn't work. While driving around that night, all of a sudden the clock backlight came on and that's when the battery charge light started coming on every once in a while.

 

Other than the headlights dimming and the fuel pump dropping in pitch from the change in voltage, I don't see any lights flickering or anything. What could be going on? I figure there is a short somewhere, but wouldn't it be more consistent than that or blow a fuse? What would make the voltage drop off that much?

 

Maybe I messed up the alternator, but why would it sometimes work and sometimes not?

 

What can I do to check this problem? It's realllly worrying me. Is it a danger to my car to be driving around before I fix it?

 

Thanks,

Sam

[Guest greimann]

Check all of your battery connections first, especially the grounds. Good ground to the block AND the body. Take all of the cables loose and clean corrosion from all contact points.

[Guest SuperDave]

I've backed myself into an electrical corner a couple times by nicely refinishing a surface, only to lose the ground attached to it because it won't ground thru paint.

[Guest the_dj]

Looks like the dash is getting opened again tonight. Aren't deadlines fun? I'm trying to get finished for Sept. 13 in AL, but things keep popping up.

 

Now I have to find new injectors because the 24# ones I have now aren't up to the task of my new heads/cam package.

 

Sam

[Guest Anonymous]

When my gauges all went wacky it was indeed a bad ground. I put a large ground from the head to the strut tower (ok so its not the most sanitary place to put it) bolt and it stopped all of it. I'll also say the datsun wiring sucks bigtime and if I do keep the car, I'm going to take great pleasure in ripping out ever single little nippon denso wire and wadding it into a ball and tossing it where it should be. In the garbage.

 

Regards,

 

Lone

[jaime240z]

Ya know my 240 did something very similar to that, except it was the ammeter that would twitch with the lights on. But not on a regular basis. After about a month and 1/2 the alternator went out. I ended up replacing the alternator and putting the headlights on relays and I haven't had the probelm since. Not sure if this is the same problem on your Z but I hope this helps.

[Guest Anonymous]

90% it's a ground problem....and there's about 6 or 7 grounding points...the hard one to find is above the differential housing. Bare em all and it should go away.