I had my head gaskets blow in my 99 3.0L and had to pull the motor and rebuild it. After dropping the motor back in, I connected the positive battery cable to the starter and the alternator. In the middle of the way down to the starter there is a bracket and what looks to be another positive loop connector on the cable. I cannot tell where it is suppose to go. The motor appears to be grounded incorrectly because every time I try to plug in my block warmer it trips my outlet. The truck does turn over but starts to backfire after running for a few minutes. If I try to drive it, it has no power and almost stalls everytime time coming out of 1st gear. Please help!!

 

Welcome to the forum

There are no extra connections on the positive starter motor cable, there can be a bracket on that positive cable that holds it away from exhaust manifold/pipe on that side of engine, its not connected to the wire inside insulation just around it to hold it in place

Block heater is not part of vehicle wiring, its a 110vAC heater coil usually installed in a core plug opening(freeze plug)
So if house breaker is tripping when you plug it in then heating coil or 110vAC wiring is shorted out, or you already have max AMPs being pulled from that breaker
But nothing to do with 12volt or Ground in engine wiring
Could you have damaged the 110vAC wire when pulling or installing the engine?

Common mistake on the distributorless V6 Rangers is Coil Pack wiring, there are only 3 coils in the coil pack, not 6
[3 4]
[2 6]
[1 5]

These are the Matched Sets of spark plugs that fire at the same time, 3/4, 2/6, 1/5
The 5 6 4 side often gets miswired, follow each wire to it spark plug/cylinder


Where the heads pressure tested?
So not cracked
Bad Head gasket or cracked head have exactly the same symptoms