Mk 1 Diesel Project

[Peter Jones]

I'm pretty sure I had mastered the multimeter,

There are many ways to use a multimeter (that's what the multi bit means)

Pop quiz. What do you use the AC (~) range on your multimeter for in the context of diagnosing auto electrical gremlins?

Pete

[Jarred]

you don't, you use the DC range for starters.

but I use the 20 V(--) range

[Peter Jones]

Sorry to crush your enginnering spirit there Jarred, but that's a 2 or maybe three phase AC alternator in your car.(alternators make - alternating current)

The AC is made into DC (more or less) by a bunch of diodes inside the alternator.

There will always be some AC ripple present when charging. The battery smothes most of the ripple.

If you can measure a lot of AC the diodes are shot and it's only a matter of time before the battery is too.

See? There's one new way to use that meter already.

Pete

[Jarred]

gah! smarty pants.

thats my new thing I've learnt for today then.

I'll give it a go tomorrow once the batt is charged, and the car is running.

actually, I should have read the question properly.

"diagnosing auto electrical gremlins"

Most I can do is check the voltage on the battery. Although aparently I can't do that either! hahahahha LOL.

[Preen59]

That's why Pete's a big shot Moderator and you're not Jarred.


Thanks for that tip Pete.. I didn't know that! (Never needed to..).

[gldgti]

That's why Pete's a big shot Moderator and you're not Jarred.


Thanks for that tip Pete.. I didn't know that! (Never needed to..).

more like its 'cos Pete is a big shot electrical Guru!

thanks pete, another trick up the sleeve

[Jarred]

So I went out to the garage this morning, to find the charger off, and a note next to it. "still charging at 4amp. NO GOOD" from Dad. Crap I thought.

Got my multimeter, and the batt measured at 12.3V, so I thought, bugger it, I'll give it a go. Pop it in the car and it starts up, no worries.

Get my trusty multimeter out, on 20 V(--) it reads 13.5V, indictating the alt is still charging properly. Whack it on 200 V(~) (smallest setting for AC) and it read steady at 28.6 V.

Current also measured at 0.00mA too.

I'm going to see if I can find the receipt for the battery, it's only about 14months old, so it shouldn't have packed it in by now.

EDIT: Found the reciept bought it 2/7/08, should still be in warrenty (spelling?) should it come down to that.

[ross_m]

Your car looks spot on! Simple but effective styling wins all the time.

How low do you think it is now in mm's?

I had to raise mine up a little when it was -80mm as the driveshafts were really close to the chassis. Mine has had a tiny notch cut out for clearance but wouldnt want to cut any more off and weld a pipe section in like some people have done..

[Jarred]

Hi Ross.

Cheers, I don't know exactly how low it is. I know it's not hitting the driveshaft yet though. I'd estimate at about 3 inches or 75mm of drop.

Once the suspension settles, I'm going to go out and set it up properly, make sure everything is clearanced etc.

[Peter Jones]

Get my trusty multimeter out, on 20 V(--) it reads 13.5V, indictating the alt is still charging properly. Whack it on 200 V(~) (smallest setting for AC) and it read steady at 28.6 V.

Current also measured at 0.00mA too.

That's a lot of AC. I wouldn't expect more than about a volt or so. You might have a shorted diode in your alternator. An oscilloscope would be the next diagnostic tool I'd apply. The wave form will quickly give away what's happening.

0.00mA ? Where and how did you measure this?

Pete