Jump to content

Ammeter wiring question on 82


Stuart Boblett

Recommended Posts

I am in the process of installing a volt meter in place of the ammeter on my 82 and have a question. From the hand drawings on Bob Johnston's site it looks like that circuit just feeds through the ammeter from the battery to the alternator and is the main circuit for the vehicle. It appears that if I disconnect the wires from the ammeter I will lose about everything on the car. If I just tie the two ammeter wires (red and white/red) together and bypass the ammeter will everything function normally. Is there any reason not to do this? Over the years I have found that a voltmeter is much more valuable to me than an ammeter in a vehicle. Am I right on all of this or am I way off base. Thanks.

Link to comment
Share on other sites

Yes, removing both wires from the ammeter and connecting them to each other will only take the ammeter out of the system, everything else will be the same. Are they just ring terminals on threaded posts? If so, you can just use the largest size capscrew & nylock nut that will fit, and tape them securely with good quality electrical tape like 3M 33+. I'd use a button head socket capscrew so that combined with the nylock nut, there won't be any sharp corners. If you add another wire & ring terminal with an appropriate length of wire when you connect the two ammeter wires, you'll have the wire needed for the + side of the new voltmeter. The negative will go to the nearest - wire or suitable metal. Keep in mind not all metal in an Avanti is "grounded" i.e. common to the battery +. You don't need to use as heavy a wire for the voltmeter as the ammeter, just whatever the volt meter takes, probably 18ga or less. 

Link to comment
Share on other sites

12 hours ago, GlennW said:

Yes, removing both wires from the ammeter and connecting them to each other will only take the ammeter out of the system, everything else will be the same. Are they just ring terminals on threaded posts? If so, you can just use the largest size capscrew & nylock nut that will fit, and tape them securely with good quality electrical tape like 3M 33+. I'd use a button head socket capscrew so that combined with the nylock nut, there won't be any sharp corners. If you add another wire & ring terminal with an appropriate length of wire when you connect the two ammeter wires, you'll have the wire needed for the + side of the new voltmeter. The negative will go to the nearest - wire or suitable metal. Keep in mind not all metal in an Avanti is "grounded" i.e. common to the battery +. You don't need to use as heavy a wire for the voltmeter as the ammeter, just whatever the volt meter takes, probably 18ga or less. 

Thanks GlenW, that is what I thought. I do have one more question. Is the ammeter circuit hot all the time and connecting a third wire for the voltmeter will cause a continual though slight draw on the battery? I think I know just enough to be dangerous. Thanks again.

Link to comment
Share on other sites

10 hours ago, Stuart Boblett said:

Thanks GlenW, that is what I thought. I do have one more question. Is the ammeter circuit hot all the time and connecting a third wire for the voltmeter will cause a continual though slight draw on the battery? I think I know just enough to be dangerous. Thanks again.

The volt meter should be attached to a lug that is energized only when the key is in the run (or accessory) position.

 

Edited by Jim78
Link to comment
Share on other sites

On ‎11‎/‎30‎/‎2018 at 8:56 AM, Stuart Boblett said:

Thanks GlenW, that is what I thought. I do have one more question. Is the ammeter circuit hot all the time and connecting a third wire for the voltmeter will cause a continual though slight draw on the battery? I think I know just enough to be dangerous. Thanks again.

Good catch, I'm more dangerous than you :( Dunno if it's hot all the time, they usually are, so you'd want to use an ign. controlled circuit as Jim78 said.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...