One wire alternator conversion- best method to run the thick power wire

Alternator power wire

  • Run straight across the front

    Votes: 0 0.0%

  • Run down and across the front cross member

    Votes: 0 0.0%

  • Route along valve cover to rear of motor then cross at the rear, back up the firewall

    Votes: 4 100.0%
  • Total voters
    4
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Overlook68

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Had my one wire 170amp alternator installed today at a local hotrod shop. I wanted to give them a small job before sending them any big tasks.

They ran the power wire from alternator down the valve cover behind rear of motor then up the firewall.

I was thinking a shorter wire could had been ran down and across the front cross member then back up to the battery. Less visible and not in the way of the valve cover bolts.

what’s your option of running power wire?
 
I have my 100 amp one wire alternator going to the battery post on the starter. I ran the wire along the passenger side inner fender and across the firewall. It charges at 14 volts at idle with the radio and headlights on bright.
 
Low route exposes the cable to elements, oil, potential road hazards depending on routing. The length is not that much different and pretty insignificant when it comes to performance in almost every case with a properly sized cable.

JMO, nothing smaller than a 6ga cable on that install. Really a 4ga would be better.

On a one wire, the main charge wire provides the sensing for output. So the cleaner the signal back up the wire the better.
 
And don't forget some sort of fuse/ fuse link/ breaker because if something in that alternator shorts you will burn it down
 
wondering why you didn't discuss how you wanted it with the shop. since this was a test, i'd say everyone failed. neither of you seemed to have any interest in discussing what you expected before the work was done
 
The battery is what filters rectified 3 phase output of alternator. If you go remote from battery, a whine that increases in frequency, may interfere with other electronics, along with sensing and regulation issues indicated above.
 
kursplat said:
wondering why you didn't discuss how you wanted it with the shop. since this was a test, i'd say everyone failed. neither of you seemed to have any interest in discussing what you expected before the work was done
Click to expand...

Or maybe I actually did discuss with them the route. To include asking that better quality wire be used and to call me if the supplied cable wasn't long enough. :rolleyes:

They didn't call me and instead used a thick stiff parts store cable. Charged me 2.5hours labor to remove old alternator, swap pulleys, install new alternator and run the wire. Taking my time with cold beverages I don't think it would had taken me more than 45 minutes.

But after reading the above post, it might be best the ran it to the battery instead directly to the starter. I just wanted a cleaner looking engine bay. Prior owner had already ran a 2 gauge amp wire from the battery.
 
67Dart273 said:
And don't forget some sort of fuse/ fuse link/ breaker because if something in that alternator shorts you will burn it down
Click to expand...

I can't recall ever seeing a factory alt wire have a fuse and the power master instructions didn't mention a fuse. Would you want the fuse close to the battery or close to the alternator? The test sheet showed 188 amps at full rpm. Thats welding power.

They did mention a separate grounding wire.
 
Overlook68 said:
Or maybe I actually did discuss with them the route. To include asking that better quality wire be used and to call me if the supplied cable wasn't long enough. :rolleyes:

They didn't call me and instead used a thick stiff parts store cable. Charged me 2.5hours labor to remove old alternator, swap pulleys, install new alternator and run the wire. Taking my time with cold beverages I don't think it would had taken me more than 45 minutes.

But after reading the above post, it might be best the ran it to the battery instead directly to the starter. I just wanted a cleaner looking engine bay. Prior owner had already ran a 2 gauge amp wire from the battery.
Click to expand...
so you gave them the cable to use and told them what you wanted and what you got wasn't correct...sounds like they didn't listen very well
 
Yes, for the most part. But I think they actually care and seam like good guys. They kept the orginal 10 or 12 gauge power wire running over to the relay area.

I was considering them for changing fuel tank and electrical fuel pump... Might just take a vacation day from work and DIY
 
Overlook68 said:
I can't recall ever seeing a factory alt wire have a fuse and the power master instructions didn't mention a fuse. Would you want the fuse close to the battery or close to the alternator? The test sheet showed 188 amps at full rpm. Thats welding power.

They did mention a separate grounding wire.
Click to expand...
The factory alternator was "so called protected" by the what was for many years the only fuse link. Sometime around 72-73? additional links were added. You want ANY protection as close to the power source as possible. In this case the battery. Some guys advocate "finding" a cheap aluminum no4 aluminum battery cable. But with that kind of amperage you need something.
 
KitCarlson said:
The battery is what filters rectified 3 phase output of alternator. If you go remote from battery, a whine that increases in frequency, may interfere with other electronics, along with sensing and regulation issues indicated above.
Click to expand...
Can you explain that?
Its just hard to grasp how normal noise and ripple around 14 volts is reduced when a junction with the battery is introduced.
 
Mattax said:
Can you explain that?
Its just hard to grasp how normal noise and ripple around 14 volts is reduced when a junction with the battery is introduced.
Click to expand...

Simple. It's because of the length of wire. Wire has voltage drop under current, and when AC elements are involved, "it gets worse." Impedance and inductance of the charge wire
 
67Dart273 said:
...Some guys advocate "finding" a cheap aluminum no4 aluminum battery cable.
Click to expand...
:realcrazy: a lot of damage would occur before that clears the fault, if it doesn't just weld itself to the body until the FD puts out the fire
 
kursplat said:
wondering why you didn't discuss how you wanted it with the shop. since this was a test, i'd say everyone failed. neither of you seemed to have any interest in discussing what you expected before the work was done
Click to expand...

Indeed.
 
Mattax said:
Can you explain that?
Its just hard to grasp how normal noise and ripple around 14 volts is reduced when a junction with the battery is introduced.
Click to expand...
A battery resembles a huge low impedance capacitor. As Del suggests a length of wire adds resistance and inductance. Having an understanding of RLC circuits, transient analysis, AC circuits is a start. All the theory can be ignored, probing around with a scope can provide evidence. In circuit design for electromagnetic compatibility, switch mode power supplies, RF equipment, micro controllers..., circuit placement, and routing of traces/wires is extremely important.
The original wiring in classic cars predates micro controllers, entertainment systems and other equipment. Equipments typically have power filter capacitors, they will attempt to filter ripple. If battery is soft or pulled, the ripple current is detrimental to capacitor life and failure will occur. Similar ripple, if battery is more remote than equipment is to alternator output. There have been many posts on whine, headlight flicker, over charging .... most often related to inadequate wiring, and connection paths.
 
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