Voltage Regulator on the fritz?

[Gav240z]

Ok I don't even know if it's a problem yet but I'll try and describe to my best ability what exactly happened.

Yesterday I drove my Z along St Kilda and it was a nice warm night lots of people out and i got stuck in moderate traffic for a while. Anyway I was heading off to a friends house and I started to notice my indicators had slowed down a little as in not blinking the same as normal.

The headlights were dimmer but the car was driving ok. Later I noticed that the AMP meter was reading in the negative which i had never seen before and thought soemthing was wrong.

Anyway I parked the car at my friends place and when I came back later I switched the car on and it seemed normal again. The AMP meter read in the + side and about 2mins later it went to the - side again after I turned teh headlights and stereo on.

So i was cruising along the freeway and I decided to switch my lights off while nobody was around and any other electrics like the stereo still no luck. I took her to 4000rpm for a while to see if that helped but no change.

So it had got a bit cold and i put my heater on with the lights and stereo again cause it was a bit cold by that stage. Anyway driving along watching the AMP meter for a while and all of a Sudden it flicks to + side without doing anything at all.

Since then it's been normal again. I can't work it out if it was the alternator it wouldn't improve it would slowly get worse. All the wiring on the car is what i consider to be in good condition and the fuses are all ok. I'm very confused.

I think it might be the voltage regulator but looking for ideas or opinions since the car is not doing it again and seems to be fine. I guess it could be the battery but I somehow doubt it.

Ideas people?

Cheers,

Gavin

[Murph]

Interesting. Sort of similar thing with my zed. Ever since I've had it it really doesn't charge much. I have to charge the battery once a week or so. Last weekend after I charged it I adjusted the voltage reg so it'd hold 14.V and thought my issues would be over. But no. It'll hold ~13V in the day, but at night it's back down under ~12.5V. My ammeter doesn't work so no idea when it's charging/drawing power from the battery.

In your case anyway, I'd crack open the regulator and just check that the little "prong"/contact isn't binding on anything. Otherwise it's likely to be a wiring problem.

[Gav240z]

Ok that sounds like a good idea. It's only really started doing it recently I guess it could be a few things but strange it fixes itself up. To me that could be as you say the vr getting stuck or making poor contact I'll give it a try and see how it goes.

With your situation anything over 12V should be fine but if your battery is always flat it could be the actual battery or the alternator not sure if you've checked those.

[Mr Camouflage]

If you are not a stickler for originality you could replace the VR with a new solid state (transistor) unit one and never have VR roblems again. I did with my first Z all those years ago.

[Gav240z]

The VR in their atm is not the original one anyway. I have a ZX internally regulated Alternator also that I've been considering but until the car starts causing some more headaches I'm not sure.

[e_racer1999]

i recommend the IR alt.... have you had your alt checked yet? i just replaced my VR with a solid state one and i am having the same issues as you. i think mine could be my alt though... just a thought

[240ZX]

Gav,

Do yourself a favor and install your IR altrenator! As I remember, you will also need to install a diode in the circuit, do a search for details, otherwise when you go to turn the engine off it will continue to run! How do I know this......you guessed it, it happened to me when I install an IR alternator. The diode can be purchased at most electronics stores. And if you haven't already done so, convert to an electronic ignition as well. Just do it!

[Zs-ondabrain]

One other possibility to consider is the GM 1-wire alt that "Z-specialties is selling right now.

It bolts right up (no modifications needed) the wire goes to your started i think? and you unplug your Voltage regulater and never use it again.

You get constant voltage even at an idle. I think he's got them for about $150 and come change PLUS shipping.

It's right up there on my "things to upgrade on the Z" list

Dave.

[59ghia]

Have you checked it? Any of that squeling <sp> going on?

Otherwise, put a volt meter on the battery, see what you have at idle, then with higher revs, then start adding loads, ie lights, heater, etc.

Good luck,

Dave

[Gav240z]

Ok guys thanks for the advice yes I have an IR alternator but it will need a rebuild. So far i havent had a repeat of the problem i think it only happens after its been in traffic for a long time with stuff like the lights, stereo and heater on at the same time. I haven't confirmed this yet though.

I haven't checked the alternator belt but it's a good idea last time I had a problem like this it was the belt getting too loose and causing the car to do all sorts of stuff.

[Zedrally]

Gav, don't worry about a re-build, just go to a wrecker or auto-lec and grab changeover.

The current unit will fail when you least expect it, usually about 300k from home on a rainy night.

The last one I got cost me $40.

FWIW

MOM

[Gav240z]

hang on are you talking about teh alternator or the VR here?