8 replies to this topic

[A9X]

Got an interesting issue i hope someone can help with.

 

Got he young blokes LH 202 on the road this week, running lovely. Finally.

 

Anyway , has his first big day out yesterday and as he gets home i want to check things out under the bonnet , make sure all is well.

 

Bugger me dead if the battery is not boiling, too hot to touch and you can hear it hissing away.

 

left the sucker to cool down and checked the wiring, yep all good, factory spade connector to the starter motor harness, and single heavier wire from the threaded connector to the + battery.

 

I figured dud alternator, so we robbed the big torana for a replacement bosch 55 amp and away he went out for the night.

 

just home, parked her up and , you guessed it, battery too hot to touch,

 

any thoughts?

 

Its a red top optima/ultima fancy pants gel cel battery. 

 

 

[Kirk]

Welby from the alternator the srewed lug goes to the battery and the spade lug goes to the instrument panel warning light 

Edited by Kirk, 20 April 2014 - 02:35 AM.

[A9X]

thanks guys, yep wiring is correct and if i remove the battery positive wire from the threaded screw the warning light comes on.

 

yes both alternators were bosch with the regulator box attached.

 

yes i  have a good earth from battery to engine, i'll check for an engine to frame earth.

 

maybe next step is to swap battery for a bit

[RallyRed]

Hi Welby,,

Some simple quick checks with the issue-

1 With engine off, what is the battery voltage? anything around 13 v would indicate no shorted cells. A number like 11v may indicate a shorted
cell.

2. With car running, anything more than about 14.3v would suggest a wacky regulator that in turn is making the alternator run flat out, regardless of the battery condition .Thus belting a pile of current into the battery and overheating.

3. Another quick check with regard to the 'shorted cell' idea...I would imagine that when you cranked the engine over, it would crank slow and the battery volts would drop quite low, as the full capacity of the battery would not be available.

4. Compare all the above to another good vehicle you may have handy...as the issue isn't about 14.3 or 14.4v or whatever, its about what is
different from normal.

Just my 2 cents worth

[Rockoz]

Check that the alternators you are using do in fact have inbuilt regulators.

As stated above check that the voltages are within those ranges.

Listen to the alternator as well.

When its charging you should be able to hear its whine.

Disconnect the small wire off the back of the alternator and start it. When you put it back on you should hear the whine.

Turn headlights on and the whine should increase. If it doesnt increase then its probably regulator problems.

If you can hear the whine ok try another test.

Start car then disconnect the battery +ve lead. Then reconnect. If the whine increases when you reconnect the battery, then the battery is probably the issue.

With the cars you have I would suggest to Jaycar either in store or online and get an AC/DC clamp meter that also has multimeter functions.

They are about 80 bucks and a great tool to have.

 

As an after thought, and stranger things have happened.

Confirm that it is a 12 volt battery.

Edited by Rockoz, 20 April 2014 - 12:00 PM.