Speedo / Tach / Gauges: I finally figured out today that the amp gauge is reading backwards

[kaley200]

Yes it has only taken me a month to notice that when I turn on the lights that the gauge moves toward charge and the opposite takes place (at idle) ie. that it moves half way to discharge when the lights are turned off. I did originally wonder why things did not appear to be charging but since the car ran well and the lights stayed bright as well as cranking over just fine I really did not look into it sooner. Is something wired in reverse?
Also, it seems that the other gauges are not really up to snuff as well. After filling with gas, the gauge read between half and three-quarters full. It is staying on half full for quite a while but was reading one-quarter full before filling so it does not seem stuck. The heat gauge goes to the top of the normal line but never beyond no matter how hot outside so may be ok. BUT, the oil pressure gauge only goes half way even at high speed and usually runs midway between the bottom and half way and is giving me a little concern even though the car runs fine with no noises and does not seem to overheat (according to the gauge). All gauges seem to react very slowly when the car is started. I know it is 60 years old this year so I can handle certain things as long as nothing is seriously wrong. This is a 55 Commander hardtop v8 auto. Thanks for any thoughts on these observations.....BUD

[TWChamp]

Do you have the battery installed with the wrong ground? That would be more likely the problem than someone connected the wires wrong on the ammeter. If you switch the battery, then you will need to repolarize the generator by using a screwdriver at the regulator to connect the BAT and ARM terminals together for one second. The FLD terminal at the regulator is grounded, so do nothing to that one.

[christophe]

You might want to read this Gus Wilson story: http://gus-stories.org/PDF/1948/April48.pdf
It says all about it.

[kaley200]

Thanks christophe, that was an interesting little story about reverse charging a battery. I can certainly see how it could happen by just noticing which post went to ground and then putting the black charger wire on that post. We know that in these positive ground 6v setups that that isnt going to do the job properly. But I was not aware that the reverse charge would actually reverse the polarity in the battery and thus really shorten its life as well as work the ammeter in reverse. Repositioning the battery, and thereby the cables, would make the ammeter read correctly but would not solve the problem if the battery actually was reverse charged. So the battery has to be charged simply with the positive charge cable on the positive of the battery and neg to neg. It is understandable that someone knowing the car is a positive ground that they might think the opposite. So now, the battery has to be recharged the proper way (pos wire to pos terminal and neg charger wire to negative) in order to save the battery and get the amp gauge working properly. THANKS AGAIN.....BUD

[kaley200]

TWchamp, thanks for your suggestion but I checked and the battery is installed properly with the designated positive terminal connected to ground. So it looks like a proper recharge of the battery is now necessary. THANKS.....BUD

[altair]

TWchamp, thanks for your suggestion but I checked and the battery is installed properly with the designated positive terminal connected to ground. So it looks like a proper recharge of the battery is now necessary. THANKS.....BUD

You have discharge the battery slowly, put a light on the battery and let it discharge completely may take three to four days. When fully discharged recharge with the correct polarity. I went through the same procedure with a motorcycle battery. Your generator will have to be repolarized also.

[TWChamp]

A few months ago I went with my neighbor to drive home his 1950 Champion. When we got there I found they had the battery in with negative ground and had the charger backwards on the battery. The battery was only a couple weeks old, so I switched the battery around and test drove the car. Everything seemed OK, but a week later the battery would not hold a charge. My neighbor was able to exchange it for another new one though, so all is well now.

[Tom Bredehoft]

This isn't important to the discussion, but no one's mentioned it so I thought I'd tack it on. Your dashboard gages are all tied to the electrical system EXCEPT the oil gage which works directly from engine oil pump pressure. It isn't affected by the electrical system.

[Bud]

If the water temperature and gas gauges are working even if they are not quite accurate means the battery is installed correctly. If the polarity was reversed, the gauges would not show any reading at all. Bud

[kaley200]

If the water temperature and gas gauges are working even if they are not quite accurate means the battery is installed correctly. If the polarity was reversed, the gauges would not show any reading at all. Bud

BUD, if this is true then you have made things easier than they were before your post. I was about to get ready to test the polarity of the battery and then thought I
would probably be discharging and then reverse charging it. Could it just be that the generator needs the quick little cross of the contacts as already mentioned or would that problem if present, have already shown itself by not charging and by now, leaving a dead battery. Am I back to my original suspicion that the amp gauge could be wired backwards? THANKS MUCH for your input......BUD

[TWChamp]

I would put a voltmeter on the battery and make sure the posts are correct polarity as marked. I like to take whiteout and paint the + and - markings so they are easy to see. Once you make sure the battery is correct charged, then make sure it has the correct ground, and make sure the generator is putting out the correct polarity. If these all check out OK, then the ammeter must be wired backwards.

[kaley200]

TWChamp, I checked both the battery and generator today and both seemed to check out as fine with both readings being the same and the battery is installed correctly with the red cable on the positive of the battery and going to ground on the motor. I also momentarily crossed the batt and gen posts at the regulator and did not get any spark so I guess things are OK. I will get at the wiring of the ammeter tomorrow. Any insight as to how difficult or easy this may be? At 74, I dont quite get under the dash so easy anymore. THANKS.....BUD

[Dick LeRoux]

We're showing our age, "Whiteout." How many youngsters are wondering, "What he heck is Whiteout?"

[TWChamp]

We're showing our age, "Whiteout." How many youngsters are wondering, "What he heck is Whiteout?"

The DOLLAR store sells it, and it seems more like a quick drying white paint. You get 2 tubes with a small ball point tip for a buck, and it comes in handy for marking lots of things.

Kaley 200, did you have the engine running when you shorted the BAT and GEN terminals at the regulator? If the generator was running and charging the battery, then you shouldn't get a spark, but if the engine was stopped, then it should have sparked, as it's trying to make the generator run as a motor.

[kaley200]

TWChamp, I have to go at it again! I thought you meant it was to be done running so that is the way I did it. Tomorrow I will do it the right way---not running. THANKS.....BUD