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myfairlady

lights and turning signal, voltage meter?????

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    Ok well I dont know where to really put this in the title but hopefully someone can help me...

    Everytime I accelerate the needle for volts goes higher and then goes back just above middle when I let to of the gas pedal.. WHen I turn on the signal lights the volt meter flickers with the the turning signals and when at night the head lights and the gauge lights get brighter when I accelerate.

    Does anyone kow what I need to do to fix this problem?

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    I'm thinking this is probably an electrical issue (sorry, it's early and I haven't had my coffee yet, LOL).

    When you step on the gas the engine and alternator turn faster. It's completely normal for the voltage meter needle to move when you accelerate/decelerate, although the movement should be minimal. Big swings indicate a problem.

    Three obvious possibilities: weak battery; weak alternator/voltage regulator; corroded cables/connections.

    Is this a new problem or endemic? How old is the battery? What year is the car?

    If this is a relatively new phenonom and/or the battery is old, then likely the battery needs replacing or you have a corrosion issue. On the other hand, if this is "normal" for this car, then it could be an underperforming alternator/voltage regulator or, again, corrosion.

    First thing to do (cuz it's free) is to check ALL wires/cables connected to the battery and the alternator (and voltage regulator if it's external). Don't cheat and just look at them. Take them apart, one at a time, and look for signs of corrosion (anything NOT metal is bad). If they look good, clean them up using a small piece of fine sandpaper and reconnect them. Remember, a shiny connector is a happy connector! The battery posts/cables would be a good place to start. Many an electrical issue has been solved just by replacing the negative (ground) battery cable. In fact, if you haven't replaced the ground cable in the last five years or so, now would be as good a time as any. It's a cheap fix (or insurance against future problems); an easy job (even for someone of limited experience. It connects to the top bolt of the starter motor); and will give you great satisfaction in having done it yourself.

    If corrosion is/was the problem you may still end up replacing the battery as the plates may have become sulphated from improper charging. If it turns out that corrosion wasn't the problem and if the battery is old, it may just need replacing. They don't last forever and the symptoms you describe are typical for a failing battery. If that's the case, it's a hundred buck fix, and you can do it yourself (wear old clothes and wash your hands thoroughly afterward, battery acid is nasty).

    From what you've described it sounds like the alternator/voltage regulator is functioning properly. However, if corrosion and/or the battery weren't the problem, then I'd get the alternator/regulator looked at. Older cars had external regulators, newer cars, internal. If the alternator was ever replaced by P.O. it's likely now internal. Most shops will check alternators for free if you feel comfortable removing it and taking it in. Again, an easy job, just remember where all the little wires are connected to. If it's bad, well then you just have to install the new one.

    Good luck and let us know how things turn out.

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    wow for a guy who has not had his coffee yet , you still gave alot of info.. It is an on going issue. yesterday I did replace the battery and it still does it.. I was thinking it could be the voltage regualtor but I need someones opinion here.

    Ok I will check the wires and take off the alternator to see whats going on.

    Thanks alot. The info is really helpful and I will check in and let you know whats going on

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    None of the things you described sounds like symptoms, they sound perfectly normal. Headlights always brighten when you accelerate, unless the electrical system had been updated. Turn signals make the gauge flicker on almost any Z, as the power is coming from the fusebox. Very typical.

    I don't see a problem other than the car is old and it may be time to upgrade your alternator to an internal regulated one from an 81' to 83' 280ZX, with my alternator upgrade adaptor.

    I also make a Headlight and a Parking light upgrade harness to improve the lighting and help save your fusebox and combo switch.

    IM me if you're interested.

    Dave

    They are also available at MSA ( www.zcarparts.com in the stock area, under "New technologies".

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    I guess it's all a matter of degree. As I mentioned in my reply, it is normal for the needle to move on acceleration/deceleration. However, if the headlights go from bright to pissholes in the snow and/or there's extreme movement indicated by the voltage guage, then at the very least Dave, you have a potential customer for the upgrade harness.

    I hate using the "replacement" system of problem solving. You tend to accumulate a lot of perfectly good spare parts before you actually resolve the issue. Oh well, the battery probably needed replacing anyway.....right? LOL.

    Sometimes a corrosion problem can be detected using the following equation: power + bad connection = heat. If any electrical terminals seem extaordinarily hot, or you smell melting plastic, it's not a good sign.

    Definitely, Dave's wiring harness is a great investment, especially if you have or are planning a headlight upgrade.

    Good luck.

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    I totally agree with Peterc. Upgrades are great for bringing the car up to date, But believe it or not I'm more interested in Resolving the issue at hand before someone installs one of my upgrades.

    Write-up upon write-up has been done on updating, cleaning, improving and resolving electrical issues in the S30's. The Key points are always this.........

    Good battery and clean battery posts. Battery Corrosion is typically the cause of resistance and bad power flow (drawing more than the bad connections can handle.)

    New or Larger battery cables. Clean connections on both ends (Battery post clamps and ring terminals) Fireman don't bring a garden hose to the fire, they bring a FIRE hose. Power transfer is essential in ANY vehicle. If the vehicles body is one larger ground plain, shouldn't the battery have a better connection to the body then the stock, wimpy 6 gauge. I always suggest a 4 gauge upgrade but I personally use 2 gauge power wire.

    A 60 amp alternator will increase the battery refresh rate when coupled with better power wires connected to a good battery. Most people who do the ZX alternator upgrade, claim better headlights at an idle, brighter lights all around the car, faster wipers, better idle do to better power to the ignition system (points, coil, key, etc)

    The headlight upgrade harness will add relays to the headlight circuit. Thus reducing general power flow thru the fusebox, combo switch, and all other wiring associated with the headlights. The power to the headlights is now going straight from the battery, to the realys, to the headlights in a much shorter run, and the headlight circuit now only controls the relays.

    The parking light upgrade harness works on the same principle. It adds a relay after the combo switch, which puts a true 12 volts back into the system, bypassing the fusebox and combo switch as high current units.

    The result is brighter exterior lights and dash lights, and no more melted fusebox and failing combo switch.

    GROUND, GROUNDS, GROUNDS!!! Make sure all of your grounds are up to date. Unscrew them, clean them, clean the surface they are connected to and rebolt them, tightly. The HLH comes with new ground wires and the surface should be ground to the bare metal, attach the ground wire to the inner frame using the inner lower valance bolts, then coat with dielectric grease over the exposed metal to prevent rust or moisture from interupting that good ground.

    Hopefully this will get you started to an all around better electrical system.

    Dave

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    thanks for the good advice. I ahve a new batery and it still does that. Also my headlights were upgraded to the H4 versions . Here in Vegas its too hot so I had not check the wires for corrosion yet. As soon as I can I will check everything clean what I can and see if I still need to go with the 60 distributor and maybe change out my voltage regulator

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    What wattage H4 bulbs do you have installed? If the alternator in your 73 is still stock, then anything over the standard 55W/65W bulbs will be a problem.

    Edited by Walter Moore
    Corrected puncuation.

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    myfairlady, don't replace the voltage regulator -- or the alternator. They're both fine if your system puts out up to approx 14.5V (and not more). If your battery is new and healthy, then the voltage should not drop below 12 or 12.5 V, give or take, depending on your charge state. Does your starter seem to turn the engine pretty well? if so, it's not either of the battery cables or the battery connection. Instead, I'd start checking the fusible links for corrosion. I think that's the most likely trouble spot.

    I think you'll get some clues where the problem is if you do a few spot voltage checks. With the lights in their dim state and the volt meter in the middle of the gauge, take measurements at the battery, at the alternator, at the fuse block, and possibly at the headlights. I'm betting alternator voltage and fuse block voltage are about the same (low), and your battery voltage is in the neighborhood of 12.5V. Then do some fault tracing to find where you experience your big voltage drop. Again, I bet you'll find a drop across the fusible links or their connections. I bet something will even feel pretty warm somewhere.

    Good luck!

    Sarah

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    speaking of hot places where the fuses are and dim lights. Last night my interior lights side makers and parking lights dont turn on for some reason but my head lights, turning signals and brake lights work fine..

    I checked the fuse box and there seems to be melted plastic around the fuse for the parking lights. Not to sound stupid but I am at this moment, could this be the reason as well as my combo switch for the lights?????

    Its always one thing after another and i realize it cause how old the car is.

    Fastwoman

    Yes the starter is new and also the battery. Your the only one that told me not to change out the alternator adn up graded and thats cool. The more info I can get the more knowledge I I gain so every little bit helps alot.

    I will do what you say just to eliminate alll sugestions in order to find whats going on.

    Thanks

    Edited by myfairlady

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    That's great and all but what she fails to put into the equation is that your Z is older than hers and may have many more electrical issues than her later Z, that had a lot of the bugs worked out by then. The 240Z's were more of a Test unit. The electrical engineers needed to be taken out back and be smacked around. Their lack of of use of relays and better gauge wiring is and has been the downfall of way too many 240Z's.

    If you really care about your Z, do the whole voltage drop reading to comfirm what everyone else has already told you, that being to Upgrade your electrical. Your fusebox is melting, Just like I said, because of bad wiring, connections, old parts and just under 40 years of wear and tear.

    My Parking light upgrade harness will put the voltage back to your circuit and relieve the Combo switch, fusebox, wiring and connections BEFORE the actual ciruit, of all the amperage that has destroyed everything in the first place. The relay that is used in the PLH is acticated by only 0.30 amps, Not the 15 that the circuit normally sees.

    It's time to update your Z. A new alternator that will quickly recharge the system, the upgrades that I offer will put relays into the headlight and parking light circuit, and cleaning all of your grounds and updating your power wires is Exactly what your Z needs now. In 6 years of doing this, not one single customer has EVER told me anything other than "Thanks Dave, this is one of the best things I've ever done to my 240Z" And of over a thousand units sold, I've only had to replace 1, for free, because of a bad choice of wiring on my part.

    Keep in mind that I also rebuild combo and Turn Signal switches for only $60 a pair. I can also Build you a completely rebuilt, like almost new, switch if yours needs to be replaced, for only $100 per switch. NOT $175 to $300 for a non rebuilt or NOS unit like you see on Ebay and other places.

    So while you do your testing, clean every connection that you come across. There are products out there that clean corrosion off and make the connection as close to new as possible.

    FWIW,

    Dave

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