Trouble starting. starter motor?batt? wiring?

[brent88]

Hey if i drive my car then stop it sometimes it starts straight away and then it wont in 10 hours (maybe somthing draining power or the batt is f**ked?) how would i test?

checked the terminals, the negative 1 always gets corrosion but i use a wire brush on it.... how effective is this and could this stil be paret of the problem, also tighten terminals really tight but dont over tightern

whilst driving if i turn the high beams on, stereo flat out(subs etc), airconditioner on the batt needle jumps between 8v and 12.5v mainly with the beat of the music(i know ive had it so this dosent happen so its not just the subs)

replaced the alternator with a 2nd hand one 3 months ago ($220) old alternator was overchargine could this have wrecked my battery?

batt has a cca of 600

i ussualy jump start the car but have to put the leads straight on the battery posts or it dosent get enough power.

i had a problem like this once with my fto and it was the starter motor lead that was on the terminal was earthing out on the chassis of the starter motor maybe i knocked that whilst driving and its the same (needed that extra voltage from a jump pack to start

what tests can i perform? i will check the alternator is charging but im pretty sure it is because the batt gauge reads nearly fourteenvolts

[brent88]

have also tried another battery but it was worse but it have been f**ked im not sure

any help is appreciated but i think i have tried most of the obious things

once it turns over it starts straight away so its not spark or fuel obiously< and i dont think its got anything to do with the ignition

[bduffman]

When you put the new alt in did you put the right tention on the belt could be slipping and not charging as much as it should
( funny story my sisters bf the other week asked me to check his car out cause the sub was missing beats turns out his alt belt had snapped haha )

A charged battery will start your car with out the alt so if your battery has charge and its not kicking over might have some thing to do with the wiring

[brent88]

got a 10 mm drill bit on my drill and drilled/ shaved the fk out of the middle of the terminal connectror..... so far so good. maybe that tiny bit of corrosion was enough(more like just a different shade of colour) there was hardly any.

pretty sure u can get a spray that stops corrosion ill get some but i dont know y it gets on the terminals so much any ideas?

[silverGPX]

Those sprays dont work, they just create a mess. I would check your wiring into the terminals is solid, because a drop to 8.5 volts even with a sub drop is massive.

[bduffman]

y dont you just add after market terminals jaycar and stuff sell them either with or with out the volt meter on it i got the one with the volt metre i think its like a 0g, 2g, and 2 8g on the terminal ( could always upgrade your wires while your at it ) i upgraded my grounds within the first week of buying the car lol

[silverGPX]

Where did you mount your ground wires bduff?

[bduffman]

umm dont remember did it few months back but upgraded the engine ground and the chassi ground with 2g i think

[brent88]

i hvae a set of those terminals on my wreck car but cbf putting them in. i got heavy duty terminals on my fto anyway and i can just look at the capacitor in the boot or the volt meter in the dash for a voltage readout.

i ran an extra ground to the strut tower when i was troubleshooting but im gona leave it there... mightaswell