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#1 |
Registered User
Join Date: Aug 2009
Location: Oregon
Posts: 611
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Ammeter to voltmeter conversion?
My '73 came stock with an ammeter, instead of a voltage meter like later models. It has been long since unhooked. I would much rather have a voltmeter. Can I get a stock voltmeter and replace the ammeter? If so what year(s) would work in my '73?
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'73 K20 Cheyenne Super Camper Special 350/TH350/NP205 sittin' on 33's. You can set my truck on fire and roll it down a hill, and I still wouldn't trade it for a Coupe de Ville. |
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#2 |
Registered User
Join Date: Aug 2010
Location: Medford, Oregon
Posts: 139
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Re: Ammeter to voltmeter conversion?
An ampmeter operates different than a voltmeter, if your going to use the original circuit then you'll have to find out what circuits were also being fed by the ampmeter. An ampmeter is a flow through device, voltage enters one side and exits the other and the meter reads that amps. A voltmeter is not a flow through, voltage enters the positive side and goes to ground on the negative side, operates like a standard voltmeter.
Most amp meters were used to measure the charging current of the alternator so your ampmeter would be "in series" with the charge line for the battery. I'm not sure on the 73 is they were the plug in gages, it would seem that an ampmeter may have the mounting nuts for the terminals due to the current. Like I said, I'm not sure on this. Your voltmeter can be installed using any 12+ switched supply and gound out the negative side of the meter. |
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#3 |
Another Day, Another Dollar
Join Date: Nov 2008
Location: North Vancouver, BC
Posts: 1,316
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Re: Ammeter to voltmeter conversion?
Do not hook a voltmeter up where the ammeter was. You'll start a fire!!
Posted via Mobile Device
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-78 K20 Cheyenne 454 long box, 4" lift, 35" MT's, '84 cab, '80 box "its hip to be square" ![]() |
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#4 |
Slots go on anything!
Join Date: May 2003
Location: Richardson, TX
Posts: 5,957
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Re: Ammeter to voltmeter conversion?
My '74 originally had an ammeter, but it's long gone. It's a pretty easy conversion to do. This was done when I got the truck, but I switched it over to another cluster. Take the cluster out, and pull the Ammeter out. remove the clips that hold the gauge to the carrier and make contact with the printed circuit. You will hook up power and ground to the voltmeter going in. (use a ring terminal and bolt it to the back of the gauge post, I am pretty sure it is a 10-24 nut). Like I said, I used the clock wiring from the fusebox (moved to a switched power terminal) and ran a ground wire from the ground block on the left side of the cowl. I put the wires through the holes in the back of the cluster. Easy Peasy.
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1974 Jimmy- 5.3/4L80e/NP241 |
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#5 | ||
Registered User
Join Date: Nov 2010
Location: Lubbock, TX
Posts: 41
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Re: Ammeter to voltmeter conversion?
Quote:
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#6 |
Moderator
![]() Join Date: Oct 2008
Location: Wentworth, NH
Posts: 4,951
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Re: Ammeter to voltmeter conversion?
This is a pretty old thread...
Fires usually get started by folks installing the Ammeter clusters in the 1976 and later trucks... usually the tach clusters but the tach isn't the piece that causes the fire. The Ammeter in 67-75 GM trucks is not a high current direct read unit like the old 1960's & 1970's Chrysler units it's in a shunt. In the 73-75 trucks the ammeter measures the voltage drop between the termination points of the shunt at the starter BAT lug and the Firewall Stud J-Block. Both termination points have an AGC fuse holder. You can use the Black/White wire from the J-Block for + feed to your VOLT gauge but you'll need to add a ground and remove the fuse from the Black wire on the starter. The 76 & later gauge clusters use a different pinout on the cluster plug. The capillary tube oil pressure gauge 1976 and early 1977 will be the easiest clusters to swap into the 73-75 trucks. Late 1977 - 1980 will require an additional wire for the oil pressure sender. This is the post in the FAQ with some pretty decent cluster pinout tables. http://67-72chevytrucks.com/vboard/showpost.php?p=4595551&postcount=2
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1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
And please let us know if and how your repairs were successful. |
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