Did I pick up 5hp (alternator drag?)

[cudabob496]

Thanks. I'm always a little nervous dealing with electrical. How's this plan sound: I have an existing autometer ammeter on my dash. I'll disconnect the wires behind it, and connect them together. Then I will run another wire from the alternator to my autometer ammeter, and then a wire from the ammeter to the starter relay. That way my ammeter will be more accurate as to what true amps in the car are doing, and the rest of the dash components, ignition, etc. will still see necessary power?

[MEK-Dangerfield]

Thanks. I'm always a little nervous dealing with electrical. How's this plan sound: I have an existing autometer ammeter on my dash. I'll disconnect the wires behind it, and connect them together. Then I will run another wire from the alternator to my autometer ammeter, and then a wire from the ammeter to the starter relay. That way my ammeter will be more accurate as to what true amps in the car are doing, and the rest of the dash components, ignition, etc. will still see necessary power?

I don't see how this will make your ampmeter accurate. If you tie the wires together that go to it now, there will be current going though them that you aren't measuring.  You will definitely be beefing up the wiring, but you won't be measuring all that the alternator is putting out with your plan.


  Mike

[Katfish]

I agree, never going to be accurate with 2 different paths.  Best option is to switch to voltmeter, or if your set on keeping amp gauge, run new wire through firewall (bypassing connectors) directly to your Autometer gauge.  Then run new wire back through firewall (bypassing connectors) to starter relay.  Leave all other factory wiring alone.  Most of the problem is the connector at the firewall.

Basically replace the factory gauge with your Autometer, improve (eliminate) the bad connections at the firewall.

[MEK-Dangerfield]

I agree, never going to be accurate with 2 different paths.  Best option is to switch to voltmeter, or if your set on keeping amp gauge, run new wire through firewall (bypassing connectors) directly to your Autometer gauge.  Then run new wire back through firewall (bypassing connectors) to starter relay.  Leave all other factory wiring alone.  Most of the problem is the connector at the firewall.

Basically replace the factory gauge with your Autometer, improve (eliminate) the bad connections at the firewall.

   

[cudabob496]

Regarding "I don't see how this will make your ampmeter accurate. If you tie the wires together that go to it now, there will be current going though them that you aren't measuring.   You will definitely be beefing up the wiring, but you won't be measuring all that the alternator is putting out with your plan." Right now my stock ammete is not hooked up.  I figure if I just connect the existing wires on the autometer ammeter, have the new wire from the alt to the starter relay pass through the autometer ammeter guage, I will be monitoring the majority of the current in the system?  If I just add the wire from the alternator to the starter relay, and leave my autometer ammeter hooked up as is, the I would probably only be monitoring a small amount of the current in the overall system? Unless I'm missing something here? I'm better at water going through valves than flowing electrons.

[MEK-Dangerfield]

From back in electronics class in 11th grade, I remember my teacher telling me electrons were lazy, and took the path of least resistance. Unless your ampmeter has all of the current going thru it, it wouldn't be accurate. I applaud you for wanting to beef up the wiring, but ampmeters can only be accurate if they are measuring ALL of the current flow.


  Mike

[Katfish]

You will be measuring most of the current, but not all.  Take a look at diagram, all the current in black wire (lights, brake lights, etc) will not be measured.  I think if you just make the connections at firewall go directly through, you can improve the system, keep everything hooked up to your autometer gauge and get accurate readings.

[cudabob496]

Well ,I just finished wiring up everything, and what I have done is disconnect the wires from my autometer ammeter, and connect them together. Then I ran another wire from the alternator post to the back of my autometer ammeter guage. Then from the gauge I ran a wire (with a 30 amp fuse) to the starter relay 12V post (which happens to be under my dash since I eliminated most of the wiring in the engine bay). So, now I have two wires coming from the alternator post. The origianl plus the one I just added. But, I just realized something. If I take the original wire from the alternator post, and put it to the 12V post on the starter relay, then my ammeter will be measuring true electric system amp load. Make sense?

[Katfish]

Couple of things, the factory gauge is not a true amp reading.  It only tells whether more current is going to battery (charge) than the rest of the car is using.  If the alternator can't supply enough current, the car will draw current from the battery (discharge) to supply the circuits.

The ONLY way to accurately measure current supplied by alternator to entire car and battery is to hook it in series.

Diagram shows where you need to put amp gauge, all current must travel through it first.

[cudabob496]

Yep, that's basically where I have the autometer amp guage. The only thing I need to do to make it completely accurate is to move the original alternator output wire to the 12V post on the starter relay. Hopefully when I crank everything up, there will be no fireworks.

[cudabob496]

Well, thank the Lord, no fireworks. Keep in mind the origianal ammeter is totally out of the picture. I at first thought I had a problem because when I started up I had about minus 4 amps showing on the autometer amp guage. so I thought I had a ground. But the voltage was good (around 13.5) so I just reversed the wires on the ammeter and everything looks good. I also tested the ammeter my turning on my electric fan without the motor running and the ammeter indicated in the negative. I went out for a ride, and I sensed the car liked the fix (true motorheads can do that, especially when they have had the car for almost 20 years). All thats left is to take the original alternator output wire and hook it up to the 12V starter relay post. Then my ammeter which is part of the new alternator wire will be indicating true amps coming from the alternator. Thanks much for everyones help and advice!

[Katfish]

It's true, if you've ever had a car long enough you can "feel" when things are right.   

[cudabob496]

Maybe it's getting a stronger spark. Who knows

[cudabob496]

Well, the original alternator wire has been routed to the 12V post on the starter relay. I'll crank it up tomorrow. Man, after almost 20 years of mods and new ignitions and 10 new aftermarket gauges, the wiring under my dash would definitely put me in the finals for a "Bubba" award.

[cudabob496]

So what other thing do I need to do, like this amp bypass deal, to my Cuda that will make it a better machine. Is there a list or book out there, or something?