Melted ground wire
Little backround. Picked Up a 72 cuda 340/auto no motor no trans. Probably sat for 30 yrs, who knows. Already had 72 340 in my garage so I had to have it and the price was right. So I picked up 73 727 off facebook from an 360 charger and did my first auto rebuild. As I rebuild the 340 I thought I should make sure my trans works and all my wiring is in order so I don’t wiping out the cam in my new motor trying to get it to fire. Borrowed an old clapped out 318 that we pulled from my brother duster that we know to run. Slapped it to my fresh rebuilt 727 and patched up the existing wiring harness in the car. Got it fired up and running, shiftin, moving, all is well. So in the mean time I got all the lights working and been fiddling with the gauges, cleaning connections and what have you. The ammeter seems to hang on the high side of center. Checking battery with voltmeter on the 200 setting It was reading like 18.5v but when I put it on 20 setting it was 13.5. So yesterday I decided to throw in a new engine harness I purchased for car and a new regulator since it looked questionable and had incorrect screws and like 3 lock washer per screw and it was pretty rusted. Cleaned up firewall with dremil and used nuts and bolts since holes were stripped. Also note the alternator was from my 69 barracuda that was converted to dual field, mopar unit that had went bad. Took it to a reputable local auto electronic guy who just rebuilds starter and alternator who seemed excited to see an old mopar unit.
To get to the point, ammeter didn’t change really and voltmeter still showed super high in 200 setting but at the 20 setting it was about 13.5. Figured Im not understanding what the difference in each setting is although I thought it just added decimal places to your reading and that all is good. I started it today to take ride around block, so I threw on negative cable and hit the key. Starter sound funny like it locked and then went which it s never done. Thought cable was loose so I gave it a twist, cranked it fire up no problem. Let it warm up about 5 min and jumped in, put it in gear went to pull out and car completely shut off. Figured negative cable was loose, went to check it and the 10 ga that goes to firewall was melting and smoking. Pulled cabled and started inspecting other wires. No visible damage. gave it minute to cool, pulled melted 10ga from main ground and tried touching it to neg terminal and it was sparking bad. Unhook everything and pushed it up driveway Went in for dinner. Came back out after dinner touch negative cable to terminal and no sparks. Car starts right up. Put voltmeter on battery 24.5 v on 200 setting 13.5 on 20 setting. At this point I’m totally confused, so I check battery on my 69 barracuda stock wiring although upgrade to dual field with voltmeter in both 200 and 20 setting and 13.5 and 13.50.
so what’s up with my meter reading?
could the high voltage be what melted the ground?
could it be the starter? although a brand new 400$ mcrobb unit I bought for my 65 barracuda for my TTI header that I keep procrastinating to install. Not to say that means it ain’t junk.
could it be the fact that I don’t have battery cables super tight? Also note I do not have a firewall ground to head, didn’t see provisions at firewall and I didn’t see one in factory diagram, and figured thats why they added one from battery to rad support, not saying that’s right but I assumed it.
couple photos below. Note I’m using the black 200/20/2 on the right of the voltmeter. I believe that’s correct but I am a dumb carpenter.
Little backround. Picked Up a 72 cuda 340/auto no motor no trans. Probably sat for 30 yrs, who knows. Already had 72 340 in my garage so I had to have it and the price was right. So I picked up 73 727 off facebook from an 360 charger and did my first auto rebuild. As I rebuild the 340 I thought I should make sure my trans works and all my wiring is in order so I don’t wiping out the cam in my new motor trying to get it to fire. Borrowed an old clapped out 318 that we pulled from my brother duster that we know to run. Slapped it to my fresh rebuilt 727 and patched up the existing wiring harness in the car. Got it fired up and running, shiftin, moving, all is well. So in the mean time I got all the lights working and been fiddling with the gauges, cleaning connections and what have you. The ammeter seems to hang on the high side of center. Checking battery with voltmeter on the 200 setting It was reading like 18.5v but when I put it on 20 setting it was 13.5. So yesterday I decided to throw in a new engine harness I purchased for car and a new regulator since it looked questionable and had incorrect screws and like 3 lock washer per screw and it was pretty rusted. Cleaned up firewall with dremil and used nuts and bolts since holes were stripped. Also note the alternator was from my 69 barracuda that was converted to dual field, mopar unit that had went bad. Took it to a reputable local auto electronic guy who just rebuilds starter and alternator who seemed excited to see an old mopar unit.
To get to the point, ammeter didn’t change really and voltmeter still showed super high in 200 setting but at the 20 setting it was about 13.5. Figured Im not understanding what the difference in each setting is although I thought it just added decimal places to your reading and that all is good. I started it today to take ride around block, so I threw on negative cable and hit the key. Starter sound funny like it locked and then went which it s never done. Thought cable was loose so I gave it a twist, cranked it fire up no problem. Let it warm up about 5 min and jumped in, put it in gear went to pull out and car completely shut off. Figured negative cable was loose, went to check it and the 10 ga that goes to firewall was melting and smoking. Pulled cabled and started inspecting other wires. No visible damage. gave it minute to cool, pulled melted 10ga from main ground and tried touching it to neg terminal and it was sparking bad. Unhook everything and pushed it up driveway Went in for dinner. Came back out after dinner touch negative cable to terminal and no sparks. Car starts right up. Put voltmeter on battery 24.5 v on 200 setting 13.5 on 20 setting. At this point I’m totally confused, so I check battery on my 69 barracuda stock wiring although upgrade to dual field with voltmeter in both 200 and 20 setting and 13.5 and 13.50.
so what’s up with my meter reading?
could the high voltage be what melted the ground?
could it be the starter? although a brand new 400$ mcrobb unit I bought for my 65 barracuda for my TTI header that I keep procrastinating to install. Not to say that means it ain’t junk.
could it be the fact that I don’t have battery cables super tight? Also note I do not have a firewall ground to head, didn’t see provisions at firewall and I didn’t see one in factory diagram, and figured thats why they added one from battery to rad support, not saying that’s right but I assumed it.
couple photos below. Note I’m using the black 200/20/2 on the right of the voltmeter. I believe that’s correct but I am a dumb carpenter.
