How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask George H. Your Own Question
George H.
George H., Technician
Category: Classic Car
Satisfied Customers: 18390
Experience:  Old enough to have worked on them when they were new
13574682
Type Your Classic Car Question Here...
George H. is online now
A new question is answered every 9 seconds

Having problems getting my two post aftermarket amp gauge to

Customer Question

Having problems getting my two post aftermarket amp gauge to show that the car is charging
Submitted: 8 months ago.
Category: Classic Car
Expert:  George H. replied 8 months ago.
Hello I will help you with your question, Do you have the brand and part number of the gauge? How is it wired now?
Customer: replied 8 months ago.
D
Customer: replied 8 months ago.
That's how it is wired now and it will drop negative off 0 when I am starting the car but won't show that it is charging once running
Expert:  George H. replied 8 months ago.
Does the "to alternator" run straight to the alternator B+ post? Is there another cable between the alternator and the positive post of the battery?
Customer: replied 8 months ago.
There is a smaller wire that runs from the positive to the stud on the alternator
Customer: replied 8 months ago.
And I am pretty sure that the wire I am using runs into the plug on the alternator
Expert:  George H. replied 8 months ago.
This is a very dangerous type of gauge that was phased out long ago as all the charging/discharge current runs into the cabin through the gauge and back out. It is a direct wire to your battery if the wire is damaged. If there is a second wire between the alternator B+ post and the battery positive remove it and see if the gauge reads properly then. Thanks
Customer: replied 8 months ago.
What gauge do you recommend?
Expert:  George H. replied 8 months ago.
For the wires to the gauge? OR what would I replace this with? If the latter it would be a voltmeter type gauge that will monitor battery voltage when the key is in the run position. They take lighter wiring and don't have the problem of a direct wire to the battery does. They shut off with the ignition switch. Please let me know how I can help Thank you
Customer: replied 8 months ago.
well I did just buy the gauge with a set of three so I would have a hard time matching them up if I get a different gauge and if I put a battery tester on the battery it says it is charging at 14 volts here is a picture of the gauge
Expert:  George H. replied 8 months ago.
The gauge will read charging amperage. It is just the wiring to it has to be heavy gauge (meaning you have to be able to run 60 amps through it safely) and that is the danger. If you had a voltmeter I would go back to it. This is an Ampmeter. Let me know what I can do to help you with this Thank you
Customer: replied 8 months ago.
So how would I hook up a volt gauge?
Expert:  George H. replied 8 months ago.
A volt gauge would be from a switched 12 volt source to the gauge and from the gauge to a good ground. Back at the battery would be best. For the illumination you want the gauge wire from the present cluster, I can help with the location if necessary.
Customer: replied 8 months ago.
Ok well I am going to order a different three gauge set up with a volt meter I will respond back to you if I have any trouble thanks
Expert:  George H. replied 8 months ago.
Great, I am always glad to help Please let me know if you have further questions Thank you

Related Classic Car Questions