Ammeter wiring question on 82

[Stuart Boblett]

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.

[GlennW]

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. 

[Stuart Boblett]

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.

[Jim78]

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 December 1, 2018 by Jim78

[GlennW]

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.