Is the Ammeter necessary?

[82355]

I am installing a later tach dash cluster into a 1975 K5. Is the ammeter necessary? I am going to use a voltage meter in the new cluster because an ammeter is just one tiny step above useless. Does the ammeter act as the "resistance" to excite the alternator? I assume not, because the one in here doesn't even work (looks like it got hot?), and the alternator charges, but I am not sure if it is still exciting the alternator.

Martin

 

[blazer74]

No, not needed

 

[82355]

Yep, found that our already.

Martin

 

[Stein]

I got excited when I saw this thread and was hoping it was the case. I still can't get my CUCV to charge. John stopped out and found an instrument fuse blown. Replaced it and driving around with the handheld meter wired to the battery it seemed to be charging for a day or three but now it's back to not charging and the fuse he replaced is still good.

 

[diesel4me]

Even if GM designed the altenator to have the field coil energized by the amp meter,you could always just run a switched 12V hot wire with a #194 bulb or a ballast resistor in the line to the #1 feild coil terminal on the altenator to excite the field and get it to charge instead..

I had one truck that refused to charge unless I put 12V to the altenator terminal sometimes--usually it would not charge until I revved up the engine over 2500 rpm or so,and I found out the original wire going to the field coil terminal was "dead"--some hack had put a custom dash in the truck and butchered all the wiring,so rather than spend a week trying to figure out what was wrong,I just used the green wire that used to go to the idle stop solenoid on the original Q-jet that was long gone,replaced by an Edelbrock--I put a #194 bulb on the wire and since it was already a switched source of power,no re-wiring was nessasary..it charged fine after that was done..

 

[82355]

Even if GM designed the altenator to have the field coil energized by the amp meter,you could always just run a switched 12V hot wire with a #194 bulb or a ballast resistor in the line to the #1 feild coil terminal on the altenator to excite the field and get it to charge instead.

I am aware of that, I just wanted to see if I had to do it or not.

Martin

 

[82355]

I got excited when I saw this thread and was hoping it was the case. I still can't get my CUCV to charge. John stopped out and found an instrument fuse blown. Replaced it and driving around with the handheld meter wired to the battery it seemed to be charging for a day or three but now it's back to not charging and the fuse he replaced is still good.

Your truck never had an ammeter anyway. CUCV's got dummy lights. Even if it had gauges, they quit using ammeter's after 1975.

Martin

 

[Stein]

Your truck never had an ammeter anyway. CUCV's got dummy lights. Even if it had gauges, they quit using ammeter's after 1975.

Martin

I didn't know what it originally had. Just what Mike swapped in.

I had one truck that refused to charge unless I put 12V to the altenator terminal sometimes--usually it would not charge until I revved up the engine over 2500 rpm or so,and I found out the original wire going to the field coil terminal was "dead"--some hack had put a custom dash in the truck and butchered all the wiring,so rather than spend a week trying to figure out what was wrong,I just used the green wire that used to go to the idle stop solenoid on the original Q-jet that was long gone,replaced by an Edelbrock--I put a #194 bulb on the wire and since it was already a switched source of power,no re-wiring was nessasary..it charged fine after that was done..

None of the gauges that Mike added work so I'm thinking there might be something to this. Not trying to throw him under the bus, just stating a fact. When John was out and found the fuse issue one of the wires to the alt was still dead when key on. I might download the CUCV wiring diagram from steelsoldiers and try something like this here.

 

[Backroads]

Your truck never had an ammeter anyway. CUCV's got dummy lights. Even if it had gauges, they quit using ammeter's after 1975.

Martin

I've never seen a Cucv WITHOUT an ammeter mounted in the space above the heater controls.

Like you said, on the left side are the red gen 1 and gen 2 lights.

 

[Stein]

I've never seen a Cucv WITHOUT an ammeter mounted in the space above the heater controls.

Like you said, on the left side are the red gen 1 and gen 2 lights.

I have one. It's pegged dead.

 

[82355]

I was talking about in the gauge cluster.

Martin

 

[smalltruckbigcid]

The gauge above the heater control is for the second alternator that runs the floating ground to make 24V. It got smoked because, 1 they were really cheap gauges, 2 somewhere somebody put power to the floating ground. Or they created a redundant ground path for that circuit. End result is the same...