Fallout from a faulty voltage regulator.

[70 Cam Guy]

I spent a good amount of time today chasing wires under my dash and testing wires. I found my problem to be a melted ACC Relay (accessory relay?)

It actually still functions but some of the insulator melted and blocks the actuator arm. I didn't suspect the relay at first because my fuel pump relay didn't suffer a failure like this.

There is light at the end of this tunnel, I probably have a solid couple hours work before I can call it done. Reassembly and a couple bulb sockets to replace but it's certainly satisfying finding the cause

[Zs-ondabrain]

I replaced my early 260Z Acc. Relay with a 30/40 Tyco relay. You're welcome to it. If you want, I'll throw it in the brake parts box. Let me know before monday.

Dave

[FastWoman]

Andy, I've got to say I admire your positive attitude in the wake of your massive meltdown. I think my language would be much more colorful than yours. I'm absolutely amazed at all the damage that was done. Scary!

I wonder whether there's some overvoltage protective device that could be installed on the alternator output to interrupt current if the alternator goes berserk.

[Zs-ondabrain]

I was thinking the same thing. Basically, a circuit controlled Relay that would break the output line after, say 15.25 VDC. Couldn't be too hard to come up with. There are countless amperage fuses, why not a voltage fuse. Something small that could be attached to the alternator, or near the VR on the fender.

Something that allows about 15.2 volts and 70 amp thru but breaks the line at 15.3 volts or 75 amps?? Anyone know of something like that?

could be a marketable item.

Dave

Edited November 8, 2009 by Zs-ondabrain

[70 Cam Guy]

I replaced my early 260Z Acc. Relay with a 30/40 Tyco relay. You're welcome to it. If you want, I'll throw it in the brake parts box. Let me know before monday.

Dave

That would be super cool of you!

I actually did a poor man's repair on my relay but a proper replacement would be much better. I used my old points file to clear the melted insulator and a razor to clean it up some more. The actuator arm makes contact like it should but I think the coil took a beating when it saw the over voltage.

Today's end of work brought a working heater again . Getting the blower and blower housing back in went faster than I thought. Before it got too cold I replaced the dash bulb sockets so I have my indicators again. Where's that dancing banana smiley when you need it?

Tomorrow I'll finish buttoning up the instrument controls and I have a Baster 2 coil I picked up today to install. After all the ignition talk the last few days I figure I better update my coil since I upgraded to a ZX dizzy a while back. At the time I didn't update the coil with it, just bypassed the resistor.

[70 Cam Guy]

Andy, I've got to say I admire your positive attitude in the wake of your massive meltdown. I think my language would be much more colorful than yours. I'm absolutely amazed at all the damage that was done. Scary!

I wonder whether there's some overvoltage protective device that could be installed on the alternator output to interrupt current if the alternator goes berserk.

Sarah, I'm glad someone noticed

After lots of projects on this car, I try to keep a clear head and the best way for me to do that is to stay positive. Never think it won't get fixed or that I won't find a solution (whether it be help from others or dumb luck). When I get frustrated, my diagnosing ideas and ability fall off a cliff. Heck, I even had the battery on the Z explode in my face last month (why I had the new optima). Without getting too cheesy, I just try to roll with it, keep my eyes forward, and remember these old cars are going to throw us some wicked curve balls. I also try to keep in mind that I love cars and I am suppose to be enjoying this experience.

I hope this thread can help others like so many have helped me with my car. It's good message board karma

Voltage protection would be fantastic. I am not sure what would be needed to have that kind of logic in a circuit. I'll ask around, there has to be something available. Sh*t they power conditioners available for my guitar amp (i don't use a power conditioner), someone must have come up with something for a car. My friends just told me I should add a voltage gauge :stupid:

[FastWoman]

I get you, Andy. It's sort of a Zen thing. ;-)

I'm thinking of two possible approaches to the overvoltage issue. One would be a modified 60A circuit breaker such as used in household breaker boxes. It would come already with both thermal (bimetal strip) and overcurrent (electromagnetic throwout) protection. The electromagnet could be rewound with many, many more turns of fine gauge magnet wire and could be actuated by a power transistor with a zener diode on its base.

The other approach would simply be a better warning system. I know that my own voltage guage is perpetually at almost full scale (16V), probably because of age and corrosion on the movement spring. I suppose it might go beyond full scale in an overvoltage situation. However, it wouldn't exactly jump out at me and grab me by the throat, screaming, "OVERVOLTAGE! SHUT DOWN NOW!" Maybe the solution is some sort of piezo alarm. That would be much easier to design and could be mounted anywhere under the dash.

I'd be interested in hearing your thoughts in 20-20 hindsight, since you've been there and all.

I'm beaming positive vibes your way, BTW. I methodically worked through my own frustrating several days with this ignition stuff. Nothing melted down, but it was frustrating nevertheless. Now I have a (better) running car. This morning I put a few things back together, and we'll be taking a beautiful fall drive a bit later. So yes, there's light at the end of the tunnel.

Peace,

Sarah

[70 Cam Guy]

Hey Sarah, I don't want to send you on a wild goose chase but I thought I've read you can adjust/calibrate the volt meter on your 280. I don't know if that means looking at another meter or actually adjusting the needle. Zen is a great way to put or maybe the Tao of Datsun?

Today's end brought a car that is put back together with working lights, fuel pump, heater, and map light (I popped the fuse when I put the test light on the glove box bulb socket). I also installed the Blaster 2 coil in place of the stock one. I'm not sure if it made a big difference but it's nice knowing this coil doesn't need to be run with a resistor. It is smaller than the stock coil so I wrapped it with a rubber strip. It's not going anywhere and who knows, maybe it's getting a little vibration dampening.

One thing that still isn't perfect and I'm not sure why. It seems my radio has little to barely audible output. I'm not sure if something is toast internally or if I'm missing something.

Here are some before and after... I was listening to my tunes courtesy of my old computer speakers and iphone

Edited November 9, 2009 by 70 Cam Guy

[WingZr0]

Is it normal for the dash volt guage to fluctuate up and down with the blinking of the turn signals or drop a bit from full to about 12 then back up again when you hit the gas?

[70 Cam Guy]

Is it normal for the dash volt guage to fluctuate up and down with the blinking of the turn signals or drop a bit from full to about 12 then back up again when you hit the gas?

On the older cars, that's pretty common. Even my buddy's Ranger did that when he installed his stereo. You could even see the dash lights dim when the turn signals were on. He eventually installed a high output alternator and a 1 farad capacitor on the stereo system.

Most of the time it's just a matter of low alternator output at idle. Do you ever notice your headlights dim at idle and brighten as you accelerate away? Our stock alternators are rated at 40-60 amps output depending on the year. They just don't have much juice at idle. Part of the problem also is that our cars have very few relays. Power for the lights go through the switches instead of using the switch to control a relay. It makes the fluctuations much more noticeable in the gauges

Dave, do your turn signal and headlight harnesses help with that? I imagine this is a major reason to do the mod, aside from taking the big current out of the dash and switches.

Edited November 9, 2009 by 70 Cam Guy

[FastWoman]

Andy, congratulations! Well, except for the radio...

I had to laugh about your Blaster 2 coil. My own coil, also wrapped in rubber (an innertube), looks just like yours. I painted my bracket in black epoxy, though.

I wish I had known about a volt meter adjustment. I actually had the thing pulled from my dash this afternoon. I was replacing all of my instrument panel bulbs while I had the dash somewhat apart. Too late now; it's all put back together.

OK, get some sleep now...

[70 Cam Guy]

Thanks! I actually wish that coil were available in black... it would look much better than red or chrome. I was actually happy to cover up the Blaster 2 sticker.

I do think it's sleep time, half this weekend I spent under that dashboard in awkward positions. I'm sure I'll be moving pretty slow tomorrow

It sure was nice the blow the cob webs out the tail pipe on my test drive. There's something satisfying about letting it wind up on the on-ramps and enjoying the twisty roads. My tach is still funny but I hear that's normal for the stock 240 tachs