Technical What could I done wrong

Changed the battery cables in my 55 sunliner and after I got done and fired it up I put a volt meter on it and it went up past 50 volts,I then went and put it on my truck and its 14.5 so how can changing battery cables cause a alternator to go wacky. None of the lights are super bright and my stereo did not fry and everything seems normal but the voltage on the meter is way too high,if there had not been any corrosion on the battery terminals I would not have touched it.

 

is it a 6 volt positive ground?

doesn't it have a generator.?

 

I would say voltage regulator has gone bad

 

X2

 

Its 12 volt negative ground now with a Ford alternator.

 

And pictures

 

All I done was change the battery cable that goes to the solenoid from the battery and the ground cable,all I done was loosen the alternator and put some anti seize on that long bolt that goes through the alternator. I am going to put the old cables back on and see what happens and can a regulator go bad by just disconnecting the battery.

 

Here is what I am working on.

 

Digital volt meter? Was it a steady 50vdc? Sometimes they jump all over the place on one charging system but not another and are not charging as much as they show. At 50v you should be blowing bulbs left and right. Try an analog meter if you have one.

 

Got my load tester out and 14.5,the digital meter was up around 125 volts at times and nothing went kaboom. If that alternator was putting out that much the battery would have exploded and I would be in the hospital,time to change the battery in the digital meter or shove it up the Snap on dealers ass if a battery does not fix it.

 

Harbor freight special? I had one that was reading my batteries at 20 volts. I tossed that sucker into the trash pile.

 

This one was a 100 dollar Snap on meter that is a few years old.

 

Maybe when you messed with the alternator bolt something changed so the alternator isn't grounded. Bad grounds do strange stuff

 

My load tester with a analog meter is showing the correct voltage,time to look at or replace the digital meter. I ran a ground from the alternator to the body and was still getting over 100 volts on the meter so I knew it had to be the meter and it was,if that alternator was actually putting out over 100 volts the stereo would have fried along with the electronic ignition and every bulb or the battery would have exploded first and I probably would have been on the news tonight.

 

Must be something with the lights in the garage making the meter go wonky,took it off the battery and it was still reading about 30 volts so something is going on. 55 is in the garage and the truck is outside so I hope its just a weak battery with the lights making it go crazy or time for a new meter but it was enough to drive me nuts wondering what was going on.

 

Jeff... START AT THE BATTERY! Positive and negative posts. Then go from there.

 

Its fine now,I just had faulty test equipment.

 

Digital voltmeters definitely get wonky when the battery powering them inside gets weak btw, the accuracy goes way out. Usually to the high side. So instead of 12.65 from an auto battery ya get 17.8 or something like that. This confounded me for a little while one day but then I remembered the 9 volt internal battery was pretty old. Analog stuff has its place, too, it doesn't get confused as easily and averages nice when adjusting regulators for example.

 

Engine running - alternator can produce 100 VAC and 14 VDC at the same time. Your battery will explode with 100VDC. Unless the battery is totally bad, which it isn't as you are able to start the engine. You have mentioned putting antisieze on the alternator bolt which may have caused it to become ungrounded to ac thus tossing spikes which can fool asian digital meters. Also, get in the habit of using a test light rather than a voltmeter and judge the brightness of the light. If you really had 100 VDC (which we know you don't) the bulb would light like a flashbulb.

Since you keep saying, 'all I did was change the battery cable' - have you considered putting the old one back. One common method of troubleshooting is to reverse self-caused problems.

 

Alternators can put out a DC and AC voltage at the same time, you may have a defective diode or two in the rectifier.

 

I put the original cables back on and it was still the same and since the lights did not get very bright I am certain it was just the meter,if the alternator was putting out too much I would have thought the analog meter would have showed it too.

 

When I first fired it up the voltage was reading around 18 to 19 and 17 with the lights on and then it started to max out in the 20 volt setting so I changed it to 200 then it started going to up past 100,I can not remember how old the battery is and probably about 2 years old so its going to be replaced today. After taking the meter off the battery and with it still on it was reading over 30 volts so that got me thinking that maybe with the low battery its getting some feedback from the ballasts of the lights in the garage.

 

The mystery is deepening,replaced battery in meter and checked other vehicles and it works fine until its hooked up to the 55. I was going to pull the alternator and have it tested so I took off the fan belt and even with the alternator not spinning I am still getting the crazy readings on the meter with the motor running so could the spark plug wires be doing something or could it be in the electronic ignition. The digital meter is the only meter picking up this crazy reading as the analog is where it should be.

 

Lol, you mean those free with purchase red ones? I put them in my heavy equipment to check battery levels, they have a failure rate of about 25% right out of the package, 50% after first use. Same as the free flashlights. Get the magnetic bolt trays, they're fairly reliable.

 

The problem is that you are testing an analog car with a digital meter. 1955 Ford was an analog type car.
KK

 

I think I know what is going on,the farther I move the meter away from the motor the reading gets lower so I think the problem is with the cheap pick up coil I installed in the distributor to get me home so I am going to replace it tomorrow.

 

God is analog therefore we do live in an analog world but does He sanction cars to be analog?.

Now then back to reality, know that most cars have capacitors here and there to cut the noise spikes which can screw up computers and sensors and noise up the radio. Your turquoise beauty could probably use a cap at least at the ignition coil and a better ground strap from engine to firewall. Moving the meter hither/yon as you have been, looks to be a good monitor of the noise sources within your car.

Last thought on this interesting thought provoking thread ... a battery cable with few strands and little flexibility will be a better ground than a flat braided one with many small wires towards eliminating the ac spikes obviously prevalent in that car. Inductance!

 

are you getting RF interference?

 

RF interference or some kind of magnetic field coming from the distributor,the meter never went crazy before and the only part changed on the motor was the pick up coil in the distributor and it was a cheap one from Autozone.

 

If your running solid core spark plug wires that's a great source of RF energy.