Placed a clamp ammeter round the main positive cable close to the battery post and with doors open (courtesy lights on), radio on and maybe something else too, the ammeter is showing 2A.
Fire up the engine and the ammeter now reads 4.2A but my question is, is that current flow FROM the battery as it was before, or is current flow now TO the battery, now that the alternator is spinning?
My clamp meter has a sign. Did the + change to a -, or the other way round?
For DC you might have to zero the meter. Most sensors have a large offset.
In most cars there is a speed at which the charging starts in my experience, and I don't think its when idling either! They used to put a centre 0 ammeter in the line to see what was actually going on in them old days. Brian
I think you might be 30 years out of date (at least).
Tim
47 years . Last car had that did that was a 1972 model
Once sold state electronics were reliable in cars there was little reason not to have an alternator that would do a fair job at idle, and once fuel injection and ECM none at all since you could open the electronic throttle to maintain idle speed under the load
Yep, when I press the "demist" button with the engine iddling there is a slight dip in engine speed followed by a change of note as the heated windscreen and heated rear window are switched on. IIRC the heated windscreen is in two halves each fused at 45 A.
That depends on the car.
My mate drives a Morris Minor in grey with a ford gearbox substituted for the original.
No issues with not knowing what is going on, no computer to c*ck things up etc. Brian
I don?t care what antique you?re mate drives but that?s hardly *most cars* which is what you said Brian!
Most cars *do* charge at idling speed.
Tim
Brian Gaff \(Sofa 2\) wrote:
Fecking hell. Standards slipping . *Your*, not ?you?re?. ;-)
Tim
Think you forget just how much routine maintenance that Morris Minor needs to keep it going - and very easy to c*ck that up too.
I guess that may depend how many miles you do and the general condition / history of the vehicle?
I had two MM vans that were both used daily for commuting and carrying the disco gear and building materials in between. One also regularly shuttled between North London and the girlfriend in Crewe. ;-)
I can only remember two instances of me being 'let down' and that was a trunnion coming out (it turns out the grease nipple was blocked and so it wasn't getting any grease (so my fault)). I managed to jury-rig a repair and still got home under my own steam. The other was a snapped half shaft and again (luckily), close to home.
The only time Mums MM Saloon let us down on the road was when a rusty brake pipe in the chassis burst from the master cylinder, again, a 'common' problem I'd not known about so couldn't plan / check for (and again, we were able to limp home under our own steam).
All I know was they were pretty easy to work on (access etc) and seemed pretty reliable in spite of not having much in the way of routine maintenance?
Cheers, T i m
and easy to work on. But a real danger to anyone in the car. If ancient cars weren't so hazardous I'd have another.
NT
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