Posted By: rockerbob
Amp gauge electrical question - 07/31/10 07:13 PM
Want to eliminate the amp gauge in my bracket car (69 Satellite) & install a volt gauge. Can I just simply unhook the wire at the stock amp gauge & splice them together or do I have to do something else?
Posted By: jamesc
Re: Amp gauge electrical question - 07/31/10 09:07 PM
don't remember the circuit off the top of my head but iirc that heavy line runs through the bulkhead connector as well. personally i would do away with it entirely but if it's feeding other circuits you'll need to feed them. the gauges and bulkhead connector are problems waiting to happen. if you can find a schematic look it over and see. imho for race cars doing away with the stock wiring is the best route and usually isn't all that expensive.
Posted By: Devilbrad
Re: Amp gauge electrical question - 07/31/10 09:13 PM
Heres a good write up on eliminating the amp gauge and rewring the charging circuit in a mid 70's Dodge truck. Should be same for your car.
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
Posted By: Sixpak
Re: Amp gauge electrical question - 07/31/10 09:36 PM
You can run both. A volt gauge doesn't get wired the same as an amp gauge. And yes, the circuit that the amp gauge is in powers everything but the starter motor circuit. You can wire up the volt gauge separately according to the manufacturers instructions. The insides of an amp gauge are nothing more than a thick piece of brass between the two posts the wire hangs off of. The amp gauge needle never touches the actual voltage - it senses the flow of juice in either direction thru the brass bar. If the gauge is fried then I'd bypass it but if not I'd still run it, especially if you still run an alternator. A volt gauge won't tell you as readily if you have a discharge or overcharge situation like an amp gauge will. And to bypass it, yes, just bolt the black and red leads to the amp gauge together and insulate well. .
Posted By: emarine01
Re: Amp gauge electrical question - 07/31/10 09:57 PM
Red to black
You may be correct in mopars <dont know how they wire their stuff> But that just sounds like a
to me
Posted By: rockerbob
Re: Amp gauge electrical question - 07/31/10 10:10 PM
Well I unhooked the wires at the back of the amp gauge & connected them together. Everythink still works (except the amp gauge ofcourse) I am getting 14.5 volts at the alternator. 13.5 athte trunk mounted battery at idle. When I rev it up the amp gauge would peg, but the voltage at the battery world DROP to 12.5 ? So I figured the amp gauge was bad. Didn't fix my problem. Still not charging at the battery when reved up. I'm not good at electrical stuff & I'm getting in over my head....I know this stuff is easy to many people, but I just cant grasp it. Any help or ideas? Maybe I should run a new wire from the gauge to the battery?
Posted By: emarine01
Re: Amp gauge electrical question - 07/31/10 10:39 PM
Check that your belt is not slipping, With the engine not running, grab the alt fan and try to turn it, if you can, tighten the belt till you cant turn the alt by the fan and start up and check voltage
Posted By: tubtar
Re: Amp gauge electrical question - 07/31/10 10:50 PM
Sounds vaguely similar to a problem I had with a '67 Coronet.
A 318 driver ( 4 door )that would peg the ammeter above idle.
The regulator was going full field and it would overcharge like you would expect.
I used a 30 amp toggle switch on the alternator output and charged the battery when I felt it needed it.
This was in the day of 100.00 beaters and assessing of priorities meant a couple six packs vs. a new regulator.
Six packs won for a while , but it was the regulator........not the ammeter that was bad.
Posted By: tonycpe
Re: Amp gauge electrical question - 07/31/10 10:53 PM
sometimes , when the brushes in the alternator get worn , they will bounce at high rpm.
Posted By: Sixpak
Re: Amp gauge electrical question - 08/01/10 12:35 AM
Ok - does the heavy black from the alternator still go through the bulkhead at the firewall? That is a potential problem, as well as the heavy red from the battery. Either or both can corrode from moisture causing resistance which can actually burn/melt either wire. Pull both plugs and look. If they are usable, wire brush and grease the connectors and try it again. Also scrape the female connectors with a paper clip or fine jewelers screwdriver in the bulkhead they mate to.
The heavy red supplies juice to the car when the motor isn't turning the alternator to make juice, like when you start the vehicle. Once the car is running, the alternator pushes juice thru the black and back thru the heavy red to charge the battery, and power all of the circuits in the car.
One fix I've done is to totally bypass the connectors in the harness; drill two holes, use two grommets and run the heavy red and black thru them and not the bulkhead connectors.
The other thing ya got to be sure of is that the volt regulator has a real good ground, as does the negative of the battery. There should be some sort of washer or Sems bolt with a toothed washer that cuts into the sheet metal for either.
Posted By: Sixpak
Re: Amp gauge electrical question - 08/01/10 04:11 AM
Any wire getting warm during normal use is seeing resistance of some sort. Put a toothed washer between the ground point and the wire lug on the negative / ground wire that will cut into the ground metal. And definitely go through the heavy black and red wires in the bulkheads. The connector ends of the male connectors can be removed from the bulkhead connector by pushing the brass connector together where it slides into the female connector. Do one at a time - push them together and pull it out of the harness. Wire brush clean, grease, bend back and snap back into the connector. If there is any melted plastic, bypass that wire going thru the bulkhead and connect it to the corresponding wire under the dash via a new hole drilled and grommeted as indicated in previous post. Do the same for the red wire. The female connector has a little tang on it that can be bent down to remove it from the firewall block connector.
Ideally the grounding point for the battery should be the frame, and not just some sheet metal in the trunk. The engine needs a ground to the frame too, and to the firewall for the under dash and voltage regulator stuff to work right.