Bad Alternator or Battery??

[CTScott]

Originally Posted by basit701

Got the throttle body cleaned. Problem is still there. I think startor motor is faulty??

Considering that battery voltages look good in various states, check the terminals of it to make sure they are not corroded and check the ground connections from the battery to the chassis and between the engine and the chassis.

[basit701]

Originally Posted by CTScott

Considering that battery voltages look good in various states, check the terminals of it to make sure they are not corroded and check the ground connections from the battery to the chassis and between the engine and the chassis.

I changed the battery terminals with the same JDM one they were clean and battery is also new so its terminals are also clean. The connection is tight and firm.

I checked the resistances between different points like Chasis and battery ground and engine and battery ground. Its like 0.1 or 0.2ohm. When i connect the DMM at first reading is like 10 12 ohm and it falls gradually to 0.1 or 0.2 ohm.

What i suspect from these results is
1) Either cables ground and positve are weak when hot. This analogy is from the weak AC compressor clutch wire. The original AC wire used to trip the compressor so i installed a relay long time ago and it works like a charm.

2)Starter motor issue.

3) Alternator issue.(I will get a JDM alternator just for checking in the evening to check whether the problem gets eradicated)

Another question: Where is the starter relay connected in Vitz(Yaris). Relay contacts might have worn.

[basit701]

LATEST DEVELOPMENT:

Being obsessed by the problem i opened the terrminals and found something. One of the fuse on positive terminal "ALT" was blown and some one had bypassed it on "Main" by connection of wire loop (2 to 3mm2). Is this can be the problem? I suspect ALT is alternator amps.

[CTScott]

Originally Posted by basit701

LATEST DEVELOPMENT:

Being obsessed by the problem i opened the terrminals and found something. One of the fuse on positive terminal "ALT" was blown and some one had bypassed it on "Main" by connection of wire loop (2 to 3mm2). Is this can be the problem? I suspect ALT is alternator amps.

MAIN is the main feed from the battery to the car and ALT is the feed from the alternator to the battery. It is unlikely that that bypass is the issue, as they both go directly to the battery terminal, but I would replace it for safety's sake.