A(lternating)C(urrent) and D(irect) C(urrent)

[sierra2dr]

Ok gang,I'm still not getting a spark. Ok,I'll admit the trigger wheel position on the crank pulley has become off-centred because I've had to weld another piece onto the existing bracket,it was sitting too flush with the pulley http://www.autosportlabs.org/viewtopic. ... 32&start=0
This picture shows the brackets to hold the ring type,where I've had to widen the gap between the pulley and trigger wheel.

But sidelining that,on my multimeter it only has the means of testing DC voltage,as I will need to test the crank sensor "Approx. 2.5V AC when cranking". Can a DC reading be converted to AC?
thanks

[brentp]

Hmmm- Unfortunately with that sensor position it will be challenging to read anything, AC or DC.

Once you get corrected, it should be straightforward to get the coil-packs to spark on EDIS only. Power, ground, coil pack connections and sensor wiring.

Going over the previous thread it looks like we hashed over the basic troubleshooting steps already. Have you tried a different crank sensor yet?

[MartinM]

You need to point that sensor at the middle of the trigger wheel, not the middle of the alternator

...and get the gap as small as possible - withing 2-3 mm max.

You might get a reading with a DC multimeter but I can't really estimate what it should be. Strictly speaking, it should read 0 volts, but that's hardly useful to differentiate between good and duff sensors

You really need to borrow an AC multimeter or spend £7.49 in the Maplins sale and get one of these:
http://www.maplin.co.uk/Module.aspx?ModuleNo=44679
- it's fantastic value at that price and it should last a lifetime so it's a sound invetsment

If you've got an ac multimeter you can put a reasonable large hex headed bolt in your electric drill (thread in the drill) and hold the sensor close to the rotating head by hand - a working sensor will give out several volts ac at reasonably high rpms (a few '000 or so)

[sierra2dr]

Hmmm- Unfortunately with that sensor position it will be challenging to read anything, AC or DC.

Hi Brent,thanks for the reply. Yes,the CAS is not attached correctly sorry to throw you off there. I'm also needing to have a go at changing polarity

Going over the previous thread it looks like we hashed over the basic troubleshooting steps already. Have you tried a different crank sensor yet?

Yes,but I need to resolve the run out on the trigger wheel first. But I just need to establish whether DC can be used for measuring the CAS voltage. I've taken out the EDIS plug and used the test lead probes

You need to point that sensor at the middle of the trigger wheel, not the middle of the alternator

d'oh thanks Martin for your reply. The picture is old and I had not yet lined up the sensor,it is misleading

...and get the gap as small as possible - withing 2-3 mm max.

I thought it was 1mm max

You really need to borrow an AC multimeter or spend £7.49 in the Maplins sale and get one of these:
http://www.maplin.co.uk/Module.aspx?ModuleNo=44679
- it's fantastic value at that price and it should last a lifetime so it's a sound invetsment

Superb,I'll get one of those,thanks again

[dave9469]

You really need to borrow an AC multimeter or spend £7.49 in the Maplins sale and get one of these:
http://www.maplin.co.uk/Module.aspx?ModuleNo=44679
- it's fantastic value at that price and it should last a lifetime so it's a sound invetsment

Superb,I'll get one of those,thanks again

Be careful with these cheap unfused meters because if you accidently put the probe in the current slot (or accidently leave it there) and try to read voltage it will put a straight short on the circuit. At best it will burn something out, at worst it will cause a fire or explosion.

I'd always encourage somebody to buy a fuses meter.

[sierra2dr]

Thanks for the advice there Dave. How do you know it is an unfused DMM,I can't see it on the specifications?

[dave9469]

Thanks for the advice there Dave. How do you know it is an unfused DMM,I can't see it on the specifications?

Go to the maplin link and look at the enlarged diagram. All meters I've seen say next to the lead connections either fuse or unfused.

[MartinM]

It's fused on the lower current range and unfused on the 10A current range - so just be very careful when measuring high currents. Otherwise, I'd go for it.

I've a 10A range on my meter and I don't think I've ever used it - volts, resistance and continuity are the most common things to use.

At best it will burn something out...

..and at best that will be the fuse in the circuit you are measuring, so it's not all doom and gloom.