Thread: Burning wire

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Well knowing that the engine has just been changed,have all the engine grounds been re-installed? Another thing I have seen two or three times,are you dead certain there are no wires pinched in between the block and the bell housing? I can't see a problem with grounding the fan, where are you picking up its power? Have you charged and load tested that battery? Just some thoughts,Hank

Originally Posted by Geronimo

Need much bigger wire
Need a fusible link
Need to check bleed on regulator
Need fire extinguisher

Wire, Cable and Tubing Solutions from Alpha Wire Company

all very good suggestions... as food for thought, I use a maxi-bus fuse instead of a fusible link... I personally think they are safer, and I keep a spare in the car... fusible link goes... you're down for the count... fuse blows, replace and keep going! (assuming it was just excessive load that caused it to blow)

I use a holder with 8 awg wire... (70 amp rating)

There is some great information and advice on using modern electronics in older cars here:

MadElectrical.com - Mad Enterprises

Whether you buy his kits or not, the tech articles are worth reading. I have applied several of them to my rig.

Pat

If you have the relay hooked to the negative terminal you have the polarity backwards---is the batt hooked up reverse?? if not you are probably creating a direct high amp short anytime the relay is energised!!!!

If you have a voltage regulator you have probably damaged it , if your alt has internal, you probaly damaged it---or both!!!

Originally Posted by jerry clayton

If you have the relay hooked to the negative terminal you have the polarity backwards---is the batt hooked up reverse?? if not you are probably creating a direct high amp short anytime the relay is energised!!!!

If you have a voltage regulator you have probably damaged it , if your alt has internal, you probaly damaged it---or both!!!

Don't have relay just grounded the fan to the cable, no voltage regulator and the battery isn't reversed

12 ga wire is good for 35 amps up to 4 ft run....it sounds like your wire should be bigger. A 10 ga wire is good for 50 amps, an 8 ga is good for 65 amps, and a 6 ga good for 105 amps, all at 4 ft or less.

My guess is that the harness is for an old, small alternator. We typically run high strand welding cable from the battery to a high amp (200 amp) alternator.

I thought that typical GM cars had a 10 ga alt wire....not 12.

Mike in Tucson

Originally Posted by robot

12 ga wire is good for 35 amps up to 4 ft run....it sounds like your wire should be bigger. A 10 ga wire is good for 50 amps, an 8 ga is good for 65 amps, and a 6 ga good for 105 amps, all at 4 ft or less.

My guess is that the harness is for an old, small alternator. We typically run high strand welding cable from the battery to a high amp (200 amp) alternator.

I thought that typical GM cars had a 10 ga alt wire....not 12.

Mike in Tucson

So should I try a 6 or 10 gauge wire?

If you have the 6 ga, it wouldnt hurt. However, the size wire choice is influenced by the ring terminals that you can find for the alternator post. For instance, if the post is a small 1/4 thread, it may be tough to find a ring terminal that fits a big wire to little post. So, first figure out what size the alternator post is and then look for the correct sized ring lug...and buy that sized ring for the largest wire you can. For instance, if the alt post is 1/4", you will have some choices for wire that will probably be 10 ga and smaller. Usually 6 ga ring lugs take a 3/8 bolt.

Depending upon the make of car, there should be a wire from the alternator output to the battery + and another wire from the battery + to either the starter (GM) or solenoid (Ford).

I used welding cable on our 200+ amp alternator and it doesnt get hot unless we are running a really high amp draw (like a Warn winch).

Mike in Tucson