Merry Christmas guys and gals. Recently installed msd 6 box in '69 coupe, mallory digital distributor too. I wired it in with no ballast resistor(some schematics I got from msd and mallory were different) has ran fine. No real miles just different shake down runs in neighbor hood. But the other day smoke was coming from under dash, no real flames but wires were almost melting. Don't know which ones they are yet. Don't know if its 30+ year wires failing or the new ignition. Any suggestions and is a ballast resistor needed? If so where does it actually need to be? Help I hate electrical toubleshooting.

 

well if your running the original wiring with a 6 box thats throwing more juice thru the lines you probably need to get some thicker wire or else it will happen again, but worse, probably an actual fire

 

That makes scence, except the box is creating the volts for the distributor, not underdash, which is where the issue is coming from. Unless I am wrong ,and believe me it wouldn't be the first time

 

the MSD box is basically a capacitor that fires multiple sparks to the plugs though thespark plugwires. it doesnt change the voltage to the accessories or the ignition (thing where you stick the key in) it should all still be at 12V.

Smoke from under the dash inside the car is probably not related to the MSD.

Gun

 

Ugh double post.....since im here why do you think the wires that burned where not fused? Almost all the stuff under the dash has a fuse somewhere in line I figured whatever burned should have had a fuse too.

Gun

 

You need a ballast resistor to tame the in-rush current. If you don't want to use a resistor, upgrade the power wire to the msd. This includes were you tap into for your primary connection under the dash. My sugestion would be to run a new wire from the battey to the msd (fused), and the run wire can stay the same (off the ignition switch)...

 

Why mix MSD with Mallory in the first place?

 

Aren't electrical fires notorious inour classics? My father's 69 caught on fire twice back in the day...

 

mine caught fire too.....but i was trying to take off the old parking break hand grip (it was broken in half) abd gave up and brought out the air powered saw. needless to say sparks and my carpet didnt get along to well, luckly i noticed the smoking so i patted it out and went back to a chisel

 

Because of the lessons learned afterthe "Great Fire of '86" involving a poorly wired 68 Firebird, when installing or altering the wiring, I solder it, heat-shrink it and forget it. If you are going to take the time to do the install or repair, do it once and do it right. Rewiring what was a beatifully running machine sucks. Doing it after having it melt in your lap sucks twice as bad. Having it been your fault due to a ****-poorelectrical connectionis both just takes it to a whole new level of sucking.