Intermittent no crank , battery flickers with bass hit, parasitic draw

[88sogreatv8]

I have an issue with my battery draining down to 5 volts after sitting in my garage for a month. The other issues i think are related is sometimes the vehicle will not crank . I have to work the ignition several times to get it to crank. I also noticed that when my bass hits my lights dim . I think it is related to a ground issue. I have done a continuity test and i have good chassis ground. The battery is new, the starter is new and i have a high amp alternator. I am thinking of redoing the ground to the engine block. It is original to the engine i got from the junkyard. this 1uz is also swapped into a 1988 cressida

 

[P Bateman]

To chase down parasitic current draw:
- switch the ignition off and remove the key
- disconnect your negative battery terminal
- Set your multi meter to AMPS and place it between the negative battery terminal and the cable

An acceptable level of parasitic current draw is around 20 to 50 mA

If the current draw is higher, start pulling fuses out one by one, each time checking the current draw, the refitting the fuse
When find the fuse that makes reading drop into an acceptable range, you know which circuit is sucking the battery dry.
From there, you'll need to diagnose the circuit.

Deal with this first before you start chasing ignition switch and audio system issues.

BTW continuity tests are NG. A thick-ass battery cable that is cut through to one remaining strand still has continuity but is clearly unfit for purpose. Resistance tests are always the best way to go. Make sure your battery cables have a clean unpainted bare metal surface to bolt onto.

PB

 

[88sogreatv8]

Update . Pulled the starter and bench tested it. Seems to be working fine. Did a draw test. showed no draw at all . My main concern is the original main starter wire and the ground wire. they both came with the used engine. Im going to replace both wires and cross my fingers. I am also replacing the starter to be safe. Update soon..