Ammeter question....

[SPYDERLK]

This is "concept" on how a voltmeter and/or ammeter should be wired....

Does not matter if car or truck or tractor or bus or gas engine or diesel... Electrical are electricals...

Dale

OP, Richard: With reference to the Schematic attached by DL Meisen, I think your ammeter is connected in the lower portion of the vertical line shown rising from the Voltage regulator - instead of in the horizontal line, above there, that branches from it over to the starter.

This would explain the symptoms you are describing. -- Your ammeter is measuring the full current from the ammeter instead of the net current (as it should) to the battery.​

 

[BertZegers]

This is "concept" on how a voltmeter and/or ammeter should be wired....

Does not matter if car or truck or tractor or bus or gas engine or diesel... Electrical are electricals...

Dale

The battery disconnect switch in this schematic is wired in the plus wire and should't be.
For optimum safety the battery disconnect should be wired into the ground wire, same cost more safe.

 

[WranglerX]

The battery disconnect switch in this schematic is wired in the plus wire and should't be.
For optimum safety the battery disconnect should be wired into the ground wire, same cost more safe.

Not relevant to discussion about ammeter.... ls relevant to application.... So what happens on a lot of VW engines (and not just VW engines) with alternators there is a condition called run on, where there is enough voltage leak through ALT LAMP that will keep coil energised and engine will not shut down allowing alternator to power system minus battery... It require actually disconnecting B+ output of alternator to battery to kill engine.... This is basically why most people upt disconnect switches in Positiv eebattery cable....

And the is this....

443 Master Battery Cut-Off Switch Wiring Instructions | Pegasus Auto Racing Supplies

Or this...

Longacre 4-Terminal Kill Switch Instructions | Pegasus Auto Racing Supplies

IN the end all that is really relevant is you open the power loop from negative battery terminal through electrical system back to positive terminal if battery.. It prevents a internal leak that can drain battery and can act as a theft deterrent if dumb thief can not fine disconnect switch and turn it on....

Dale

 

[BertZegers]

Not relevant to discussion about ammeter.... ls relevant to application.... So what happens on a lot of VW engines (and not just VW engines) with alternators there is a condition called run on, where there is enough voltage leak through ALT LAMP that will keep coil energised and engine will not shut down allowing alternator to power system minus battery... It require actually disconnecting B+ output of alternator to battery to kill engine.... This is basically why most people upt disconnect switches in Positiv eebattery cable....

And the is this....

443 Master Battery Cut-Off Switch Wiring Instructions | Pegasus Auto Racing Supplies

Or this...

Longacre 4-Terminal Kill Switch Instructions | Pegasus Auto Racing Supplies

IN the end all that is really relevant is you open the power loop from negative battery terminal through electrical system back to positive terminal if battery.. It prevents a internal leak that can drain battery and can act as a theft deterrent if dumb thief can not fine disconnect switch and turn it on....

Dale

Most technicians do it wrong and put the battery disconnect in the PLUS. ( on a vehicle with minus = ground)

Think of this; a person is diving a race car. The battery disconnect is on the mudguard were it can be reached from the seat and from the outside.
The car is in an accident and the driver is stuck, the battery ignites the car. The first responders turn of the battery disconnect and try to extinguish the fire but the battery keeps igniting the vehicle. The driver dies.
Why ? Because the battery cut of switch was not in the ground wire.

Dale; I know this is a tractor forum, not a racing forum. But don't say that in the plus or in the ground is the same. It is not! I hope my example explained.

 

[WranglerX]

Most technicians do it wrong and put the battery disconnect in the PLUS. ( on a vehicle with minus = ground)

Think of this; a person is diving a race car. The battery disconnect is on the mudguard were it can be reached from the seat and from the outside.
The car is in an accident and the driver is stuck, the battery ignites the car. The first responders turn of the battery disconnect and try to extinguish the fire but the battery keeps igniting the vehicle. The driver dies.
Why ? Because the battery cut of switch was not in the ground wire.

Wish you can supply supporting documentation to your argument... You seem to be ignoring mine....

Dale; I know this is a tractor forum, not a racing forum. But don't say that in the plus or in the ground is the same. It is not! I hope my example explained.

Wish you could supply supporting documentation for your statements... You seem to want to ignore my documentation...

Polarity has nothing to do as if switch goes open circuit or not....... We discovered we needed to put switch in positive side after incident at auto X track after a car actually had cause use disconnect and engine did not kill... It was discovered that there was a run-on situation because of alternator output.... You can put switch in negative all you want but if alternator continues to put out voltage and since alternator frame is grounded it is perfect power supply to run engine (battery excluded) ... One has to wire cutoff switch so It functions as intended not by archaic rule that may make non operational...

Don't care if its a tractor or race car or street drive performance car it has to function as intended, poliarity does not matter....

I worked tech inspection at auto X track off and on for over 10 years.... You would be surprised how many times I picked a car at random and said "start it up" and they did, I went to cutoff switch and flipped it, many times car did not shut off..... It's not polarity dependent its application dependent...

Its just like people don't understand you need some sort of safety switch on electric fuel pumps so in situation where engine dies (car stall because of crash) you need to have cutoff for fuel pump... IF driver is unconscious, and can not turn off ignition and fuel pump continues to run it can spew fuel out till tank empty, do you want big puddle of fuel around car crash scene... That is why almost all electric fuel pump need a safety switch of some sort so if engine dies it shuts down fuel pump... Some cars use impact sensor as disconnect, some use pulses from electronic or mechanical ignitions.... When people convert from mechanical fuel pumps to electrical (non ECM cars) our group always recommends something like this...

Fuel Pump Safety Switch



Dale

 

[RickB]

In the world of tractors (not race cars) run on can be a problem when alternator conversions are done. A simple charge indicator lamp in the excitation circuit typically provides sufficient resistance to alleviate the problem. A diode in the circuit accomplishes the same thing. Both are passive cures that require no though or action.

 

[WranglerX]

In the world of tractors (not race cars) run on can be a problem when alternator conversions are done. A simple charge indicator lamp in the excitation circuit typically provides sufficient resistance to alleviate the problem. A diode in the circuit accomplishes the same thing. Both are passive cures that require no though or action.

Most definitely....This is solution popular in VW world...

Dale

 

[BertZegers]

I have started a new post in Safety. "Battery disconnect switch" it explains why the switch is best put in the ground wire.