thanks for your help, i have a set of those sun pro guages were do you hookup the volt and or amp guage to, on a 75 f-250 thanks

 

Which gauge is it? A volt gauge (voltmeter) is very different than an amp gauge (ammeter), and as such, the connection scheme is entirely different between the two. Does the gauge you want to hook up say "volts" or "amps?"

Are you asking how to hook up both at the same time?

 

i think its the amp gauge but could you help with both hook ups thanks my truck has a 390 in it

 

Let's keep it simple. What does your gauge say?

 

Usually a volt gauge is fairly simple to hook up. Just need a keyed power source and a ground. But amp gauges will need to be hooked up in series (all the power from your alternator going through it). So depending what you got there can be quit a difference. Good luck.

 

VOLT METER
There should be a red wire. That goes under the dash to the fuse block or ignition switch. Use your test light and find a fuse that's on off with key.
There should be a black wire, put that to ground on the dash somewhere. Usually there is a third wire, it may be white or purple. This one goes somewhere that is on/off with the parking or head lights (prob on the light switch).

AMP METER
There should be 2 big terminals on the back of the meter. Series means the gauge must "interrupt" the wire coming from the alternator. In other words, take the main (thick) wire off the alternator and run it to one side of the gauge. Then run another wire from the other side of the gauge, back to the alternator where you took the first one off. (whew!) If the gauge reads backwards, switch the wires on the back of the ammeter. Hook up the night light just like the voltmeter.

Personally, I dis recommend the use of an ammeter in 12v systems. Unless V/A are mounted together. All an ammeter does is tell you if your alternator is charging. It doesn't tell you battery condition. (If it's going to start when you shut it off) A voltmeter tells you if your alternator is working AND what state the battery is in.

 

THANKS VERY MUCH

 

I was told by EZ wire tech if I want to hook it up that I use the wire coming out of the fuse box that goes to the starter and attach it to one post on the gauge then attach wire to the other post then to the starter selinoid.