Oh oh, wrong gauge

[Grover 1]

After looking at aftermarket gauges, I found a really clean factory set of gauges and bought them instead.  Now that I get home I see the panel I bought has an amp meter, my 78 came with a volt meter.  What do I need to do to get the set to work with the amp meter OR should I switch to a volt gauge and if so do I need to change the printed board behind the gauges?  Hope this makes sense.  Thanks.

[454ss]

http://www.73-87.com/7387garage/interior/factory%20tachometers.htm

[Captkaos]

I would sell it, and DO NOT hook it up.  You will need to completely rewire the truck as that is a sure why to burn up you truck.

[ccz145a]

While it is true you cannot (read, do not) connect a voltmeter in place of an ammeter keeping everything else the same, you can hook up the voltmeter to this cluster in this case. 1) the connector for the 78 is pinned for a volt meter. 2) the voltmeter connectors are 90deg apart and use another ribbon that trace back to the connector in the right place with the right wire (just so you know, the ammeter connectors are 180 deg apart). Compare the two circuit panels to verify.

I did this in my 75 cab swap with complete interior 84 harness. I used the 75 cluster and circuit panel with the 84s voltmeter. I did test the setup with a little square 9v battery first, to confirm my tracing of the ribbons where correct before I juiced it with the 650cca 12 battery, though. Better safe than sorry.

If done wrong you will smoke the truck.