70a fuse in main box keeps blowing

Sparks do fly, the last connection on the cables is ground
to a metal , on engine not battery,
this will make a small, spark. all do, that. done right.
but if done backwards, a huge spark with the 2 batteries bucking each other, and damage will happen.!
yes you may blow the main fuses,
my guess you blew the 80amp fuse in the main fuse box under hood.
did you put the new battery in correctly Plus to PLUS
and NEG to NEG lugs, if not, BOOM AGAIN.
open hood,
fuse 1, if it ok, then the others fuse to the right blew.
when fuse 1 blows, all things die. zero power to anything in car
including head lights, (head lights are always the first check)

Hi John!

• There is a short in the Circuit. Do not put any more fuses in it.

• Take it to the Electric Shop to have it diagnosed.

Good Luck,
JP

u have a dead short on main live wire check for overheated wires

Sounds like the magnet in the a/c clutch has failed.

I think there is a short in the system, possibly happened while replacing the main brain.

U MIGHT WANNA CHECK THE FUSABLE LINK IN THE FUSE BOX UNDER HOOD SMOTHING MUST HAVE GROUNDED OUT CAUSING IT TO DO THAT ..THE ONLY OTHER THINGS IT COULD BE WIRES IN THE HARNESS IT SELF R OLD OR HAVE BECOME HOT AND R TOUCHING SO CHECK THERE STARTING WHERE FUSE BOX IS ...THEN CHECK URE ECM ITS SELF AT AUTO ZONE IF U HAVE ONE NEAR HOPE THIS HELPS

replace brake light switch down on the brake padel/has short in it

check your fues socket main wire if it not getting sparked or is broken in between...

I would suggest that you check to see if the battery is connected properly---correct polarity!

If connected wrong, main fuse will blow. Lights come on because power is routed through the frame (ground) briefly.
Hope this helps.

Replace the lighter assembly, it is shorted, this is very common.