Ammeter bypass question

Want to do the MAD electrical ammeter bypass on my Duster but I have new wiring harnesses all the way around and dont really want to damage them by widening the wire pass through at the bulkhead. Could I get the same or similar results by simply splicing the two wires together at the gauge and running a 10 gauge wire from the alternator to the starter relay? I'm thinking that this would work and/or atleast decrease the load on the smaller harness wires. I know the best fix is to do the voltmeter conversion but I dont have the cash on hand right now for it. Thoughts?

yes going from alt to relay would definitely reduce the load thru the bulkhead. I would go with 8ga.

What amp rating alternator are you running? That should determine the wire gauge size

That's pretty much what I did. Works fine. With a stock or moderately upgraded alternator 10 gauge would be fine. OE was 12 gauge max. Bigger wire sizes for a bigger alternator. Also need a fusible link or a fuse in the wire. The AP store will usually stock 14 gauge fusible link which matches up with 10 gauge wire (2 gauge sizes smaller).

Your new harness should have ignition switched accessory taps or there is one on the fuse block. Either would be fine for a low cost AP store voltmeter which could be mounted in an inconspicuous spot under the dash.

You can leave the harness/bulkhead as is if doing the wire around.

I build custom 8ga wire around set up with fusible link. If you want to discuss this send me a PM.

I've even left the original wiring in place.

The alternator I'm running is a 90 amp. In my youth I had an expensive stereo in the car and every time I would crank the system the lights would dim to the beat of the drums or base, I was running a 40amp then so I replaced it with the 90 amp to cure the problem and the alternator has just kind of ridden in the car since then. I figure if I'm going to do the electrical work around it would save me some money in the short term not buying a new alternator, plus the pulleys would need to be changed out as I have a March system on there now.

If you ever want or need to use the 90 amp output, 8 gauge would be preferable vs 10 gauge as many have suggested. You probably need to go to an auto electric store to get 12 gauge fusible link to go with it or use a "maxi fuse" from NAPA rated around 120 amps.

That said, a 10 gauge bypass would be a whole lot better than what you have now. You are fortunate the bulkhead connector hasn't melted yet. I melted one years ago with a 60 amp alternator.