battery Overcharge

[2toneFatone]

The battery on my '72 240z is leaking acid, and has been replaced several times (on warranty). I don't know much about automotive electronics, so I took it to a mechanic who told me that my voltage regulator was overcharging it. So I got a new one from MSA, and he installed it. After starting the car, it started to melt itself. The old one still works (incorrectly) when hooked up in the same manner. Was there something wrong with the part? should I not go to that mechanic anymore? or could there be a different problem?

[MikeW]

It seems to me that any competent mechanic should be able to test your charging system: alternator, voltage regulator, and battery. Are you saying that the newly installed voltage regulator is now melting?

Edited January 10, 2009 by MikeW
typo

[Zs-ondabrain]

Sounds like a short somewhere else, possible a bad alternator? I competent mechanic should be able to test everything beforehand. There's a limiter that's not limiting, if you know what I mean.

Maybe it's time for that 81' to 83' 280ZX alternator upgrade. Internally regulated, no more external voltage reguilator to go bad, better amperage to the battery, etc, etc. I sell the the adaptor for the conversion. $15

Dave

Edited January 10, 2009 by Zs-ondabrain

[DeesZ]

Maybe it's time for that 81' to 83' 280ZX alternator upgrade. Internally regulated, no more external voltage reguilator to go bad, better amperage to the battery, etc, etc. I sell the the adaptor for the conversion. $15

Dave

I highly recommend the alternator conversion. You will not be sorry, and if you are worried about originality, it's easily reversible when you want to use the old stuff for a show or something.

Step one: Have a check done on the charging system to determine the origin of the problem in your system. If it's either the alt or the reg, consider the upgrade. Dave's stuff is top shelf and quite reasonably priced. Happy customer here, several times over.

[2toneFatone]

Are you saying that the newly installed voltage regulator is now melting?

The new one melted. The old one doesn't melt, but puts out too much voltage. The mechanic was confident that the regulator was that problem, and not anything else.

Maybe it's time for that 81' to 83' 280ZX alternator upgrade. Internally regulated, no more external voltage reguilator to go bad, better amperage to the battery, etc, etc. I sell the the adaptor for the conversion. $15

I hadn't thought of that, but it sounds like it would make for a lot less headaches. Is the new alternator and the adaptor all I would need to do that conversion?

[DeesZ]

That's about it, and you are rid of all of the issues that a mechanical regulator presents! Check it out here: http://www.classiczcars.com/reviews/showproduct.php?product=11&cat=7

This will not resolve 'other' problems like a short, obviously.

[Zs-ondabrain]

And when you do all this, Make sure to upgrade the Battery cables to no less than 4 gauge wire. You can make your own and buy the new connectors and mounts at the local auto parts store.

But make sure to also make a new ground wire from the battery to the firewall (8 gauge) and also make one to go from the starter mounting bolt over to the ground point on the fender (8 gauge), where the harness is grounded. This will reinforce a great ground to your electrical system.

Just remember that the better the grounding system, the less problems you'll have down the line. I have done all these and also have a ground wire going to the Head. Grounding the head directly helps to reduce electrolisis in the cooling system, that will normally eat thru aluminum and cause premature failure.

Dave.

Edited January 11, 2009 by Zs-ondabrain

[emccallum]

I was having electrical issues on my 71. A few things that I did. Replaced the voltage regulator, altenator, battery, checked all connections and grounds. It has been a while...but as I recall there is a large red/white striped main wire that runs from the altenator to the fuse box. Make sure it is well connected, as it will heat up quickly if it has a lot of resistance (poor connections). You can run another wire (fused of course) from the positive of the battery straight to the altenator (pos side). This will help reduce pressure on the fuse box. Sometimes, changing one part puts another over the top. This system wasnt that great 35 years ago!

My car is rarely driven, so this wotked for me. If I was going to drive it daily, I would consider upgrading to the internally regulated zx altenator, as others have posted.

Edited January 19, 2009 by emccallum

[Daniel]

The white wire on the harness that connects to the volt reg is not making connection thru the connector. Thats the wire that tell the it charge or not.

[FastWoman]

As I recall, those mechanical voltage regulators are adjustable. Your factory service manual should tell you how to adjust the regulated voltage.