AMP gauge reading

[Larry E]

What might it mean if the AMP gauge reads 40 on the chg side of the gauge at all times?

Larry E

 

[Silvertip]

Re: AMP gauge reading

It means the battery is being charged at a 40A rate. The gauge should drop down to 5 amps or so after a relatively long run but that depends on how discharged the battery is. If you only run a mile or so at a time the battery may never get fully charged.

 

[NYBo]

Re: AMP gauge reading

Are you saying it reads this way even when the motor isn't running? If so, the gauge is defective.

 

[Larry E]

Re: AMP gauge reading

Yes without the motor running it is at 40 on the charge side.

Are you saying it reads this way even when the motor isn't running? If so, the gauge is defective.

 

[Larry E]

Re: AMP gauge reading

Look at this picture of the back of my dash and tell me whether it looks like all the power for the other gauges and light switches comes through the red wire attached to the amp gauge on the lower right hand side. The reason I am asking this is because I do not seem to be getting any power (pos) to the rest of the gauges which dazy chain off of the amp gauge. Could this be because the amp gauge is bad? OH by the way big day today. The motor started on the first try. This is a big deal to me because I pulled the motor and replaced it, rebuilt and reinstalled it recently. SO I am down to cleaning up the electrical and getting all the gauges working.

Larry E

 

[Silvertip]

Re: AMP gauge reading

1). With the amp gauge reading +40 without the engine running says two things. A) it is wired backwards and B) you have way too much current draw with nothing operating. Disconnect one wire and see if the gauge goes to the center (zero). If not, the gauge is toast. If it does, you have a serious wiring issue.

2) The gauges should not be powered off the amp gauge. They should be powered off the "A" terminal on the ignition switch.
3) The amp gauge should have the wire from the charging system connected to one lug and the other lug should go back to the starter solenoid where the positive battery cable is attached.
4) The "B" (battery) terminal on the ignition switch should be connected to the side of the amp gauge that has the wire going back to the starter solenoid.
5) With the engine off, key in run, and any accessories running the amp gauge should read on the negative side of zero. With the engine running the gauge should read on the positive side of zero.

 

[Larry E]

Re: AMP gauge reading

That is great input Silvertip. I really appreciate the detail. I will do as you have suggested. One more question. Would I be better off with a volt gauge or keep the amp gauge?

1). With the amp gauge reading +40 without the engine running says two things. A) it is wired backwards and B) you have way too much current draw with nothing operating. Disconnect one wire and see if the gauge goes to the center (zero). If not, the gauge is toast. If it does, you have a serious wiring issue.

2) The gauges should not be powered off the amp gauge. They should be powered off the "A" terminal on the ignition switch.
3) The amp gauge should have the wire from the charging system connected to one lug and the other lug should go back to the starter solenoid where the positive battery cable is attached.
4) The "B" (battery) terminal on the ignition switch should be connected to the side of the amp gauge that has the wire going back to the starter solenoid.
5) With the engine off, key in run, and any accessories running the amp gauge should read on the negative side of zero. With the engine running the gauge should read on the positive side of zero.

 

[NYBo]

Re: AMP gauge reading

I vote for a voltmeter.

 

[Silvertip]

Re: AMP gauge reading

I vote for a voltmeter.

I wholeheartedly agree. Far more useful and you eliminate a very long run of wire through which charging current from the alternator must pass through on its way to the battery.