Battery died, replaced it, still no start

[Thoglan]

Where did you touch the voltmeter black lead? should be on the engine metal and not the chassis. Compare the reading (while cranking) when touching the black lead to chassis and to engine metal and if they are the same then the engine ground strap is good.

That was measuring the voltage change with the red lead on the jump post (the metal loop not the nut). And the black lead on the ground post in the drug bin next to the jump post.

Where should I be measuring from on the engine? I had planned to put a jump lead from the metal loop by the oil filter housing and connect it to the ground post in the drug bin and try start the car. Presumably if it started well once grounded that way then the ground strap underneath must be bad?

[eacmen]

Tried reading through all these posts and maybe you already tried this. But have you measured resistance from the chassis to various points on the engine and starter? Or visually inspect the grounding straps?

I would also check all the grounding cables in the ECU compartment.


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[bigjae46]

I also just retested cause I didn't trust myself and realised I had the multimeter hooked up to the negative lead. The actual reading from positive lead to jump post is 0.3 ohms, and the resistance from the multimeter is about 0.2 so the battery cable is fine. Lol, electrical stuff is definitely not my strong suit.

Tried to start the car yesterday with a fully charged battery reading 13.1v across the terminals and it didn't even start just cranked over a couple times. Voltage at the jump post fell below 8v while cranking so I think there has to be a bad ground somewhere.

I know you just got a new battery, have it tested. Sometimes new batteries are bad...not unheard of.

If the battery is good then you probably have a bad starter or starter solenoid. Usually the solenoid. Then I'd also check the alternator, might be a good idea to replace the regulator. The brushes are likely well worn unless you recently installed an OE reman. Valeo and Bosch rebuilds don't normally replace the regulator.

[Thoglan]

I know you just got a new battery, have it tested. Sometimes new batteries are bad...not unheard of.

If the battery is good then you probably have a bad starter or starter solenoid. Usually the solenoid. Then I'd also check the alternator, might be a good idea to replace the regulator. The brushes are likely well worn unless you recently installed an OE reman. Valeo and Bosch rebuilds don't normally replace the regulator.

Alternator was replaced with an OE reman one 2 years ago, I think the alternator is fine since the battery sits at a solid 14v while running and it's not that old. Could be starter though, although I would have thought if it was bad it wouldn't be starting at all. Could be wrong. I might end up getting a new starter just because this has been such a ball ache I don't want to have to go through it all again if the starter does go bad.

The car started up okay with a jump lead grounding the engine, still a little slow but the contact wasn't the greatest either. The voltage also didn't drop as low with the jump leads grounding it. Only dropped to just below 10v as opposed to below 8v yesterday. I think all of that suggests the engine ground strap is causing the issue.

[sapote]

To know what voltage the starter having, you need to measure from the engine black cable terminal (at the jumper post but not on the big nut) and the engine loop near the oil filter ( or the head) while cranking. Measure the battery cable resistance is not the sure way as even a tiny wire has less than 1 ohm the same as the cable 20x larger. So measure the voltage with larger starter current flow is the proper way.

[sapote]

During cranking, the voltage at the battery should be not less than 9v, and this mean the measured voltage at the engine black cable to the engine should be not less than 8.5v (assuming 0.5v drop on the long red cable).

[bigjae46]

Alternator was replaced with an OE reman one 2 years ago, I think the alternator is fine since the battery sits at a solid 14v while running and it's not that old. Could be starter though, although I would have thought if it was bad it wouldn't be starting at all. Could be wrong. I might end up getting a new starter just because this has been such a ball ache I don't want to have to go through it all again if the starter does go bad.

The car started up okay with a jump lead grounding the engine, still a little slow but the contact wasn't the greatest either. The voltage also didn't drop as low with the jump leads grounding it. Only dropped to just below 10v as opposed to below 8v yesterday. I think all of that suggests the engine ground strap is causing the issue.

Check the strap from the pass side engine mount bracket to the chassis. Sometimes the tab will break off.

[Thoglan]

Check the strap from the pass side engine mount bracket to the chassis. Sometimes the tab will break off.

Yep this is at the top of my list to check at the moment, unfortunately just haven't had the time to get it up in the air and get underneath yet. I'm hoping this is the issue.

[Thoglan]

During cranking, the voltage at the battery should be not less than 9v, and this mean the measured voltage at the engine black cable to the engine should be not less than 8.5v (assuming 0.5v drop on the long red cable).

Thanks Sapote. Will measure the that next time I start the car up.

[Acarv_426]

I had a similar issue a while back and it was the grounding straps.

[Thoglan]

Just to update this. I don't want to jinx it, but after cleaning the contacts on the ground strap to the chassis rail from the engine, the car started up back to back 7 or 8 times. Starter still sounded slightly slow on the later tries but I think that's just as a result of the battery voltage dropping a little each time.

All errors are still present on the dash and still no access to the DSC in INPA so I think the DSC unit is dead. I found one for sale locally and will swap it in and report back. I'm leaning towards replacing the starter anyway as well just so I don't have to think about it.

[Thoglan]

Thankfully ending this thread. Put my replacement DSC unit in. Opted just to replace the module and leave everything else in place that way I didn't have to disturb the brake lines and no bleeding was necessary.

New module in and all lights are gone from the dash and running good.