Alternator output results: dead alternator? *Updated results* - Saxperience

Gabbastard · 28th November 2013, 16:14

Car in question is my AX with a VTS engine and alternator(5groove pulley type), so VTS setup but without PAS or ABS.

Car chuckdd it the other week coming back from my mates. My battery light came on really dimly, gradually got brighter, then i indicated and the gauges all died, car spluttered and i made it into a parking space. My dad met me and juiced up my battery using jump leads for 5 mins. Started my car no problem, drove a few miles and the light was getting brighter again, so stopped and juiced up the battery again.

Tested the alternator today after charging the battery with a good mains charger. Car started fine. Here are the results

Car idling with no accessories or lights on: ~13.5v
Car idling with dipped beam on: ~13.4v
Car idling with blower on full, full beams, brake lights,hazard lights on,but head unit off: 13v, ocassionaly dropping just below.

Weirdly, if I switch the hazards off but put the indicators on, the dash battery light dimly flashes in time to the indicators, but doesnt with the hazards. :-s

Shagged alternator? 13v seems pretty low as in a Saxoit would be running ABS and PAS as well, despite the fact I was running everything at full tilt except the radio.

f13sta · 28th November 2013, 19:26

Sounds more like a wiring fault.
You be looking for around 13-13.8 v
However how long did you leave the multimeter on for.
Could be a goosed regulator.

wullvfr · 28th November 2013, 19:54

Usually a decent charge rate will be above 14v but so long as its 13v and above it will theoretically charge the battery,problem is if you make short journeys the battery never gets time to charge back up after being depleted after cranking the engine.

I'd test the alternator directly,iirc you can remove the block connector and see what voltage it is giving out.

Gabbastard · 28th November 2013, 20:02

Quote:

Originally Posted by f13sta

Sounds more like a wiring fault.
You be looking for around 13-13.8 v
However how long did you leave the multimeter on for.
Could be a goosed regulator.

Left the multimeter on for a bit and it was holding fairly steady as long as the indicators/hazards werent going, then it would fluctuate a little, not a huge amount though.

Quote:

Originally Posted by wullvfr

Usually a decent charge rate will be above 14v but so long as its 13v and above it will theoretically charge the battery,problem is if you make short journeys the battery never gets time to charge back up after being depleted after cranking the engine.

I'd test the alternator directly,iirc you can remove the block connector and see what voltage it is giving out.

My alternator has the big M8(iirc) ring connector so i can just probe that. Ill give it a check tomorrow.

Gabbastard · 29th November 2013, 12:35

Right so went back out today and the charge at the battery is 13.7 with nothing on, dropping to 13.1 with everything on. Output from the alternator terminal, probing the ring connector and the alternator body shows as 14.4-14.5v, so clearly the alternator isnt the issue.

What would this be indicative of?

I wouldnt imagine theres a wiring fault in the engine loom as that was removed from my Saxo which was running perfectly. Battery +ve cable or ground cable? I checked the resistance between the battery -ve and the engine block, showing up as ~60Ω.

Thanks in advance.

Kwik-Nick · 29th November 2013, 13:30

Quote:

Originally Posted by Gabbastard

Right so went back out today and the charge at the battery is 13.7 with nothing on, dropping to 13.1 with everything on. Output from the alternator terminal, probing the ring connector and the alternator body shows as 14.4-14.5v, so clearly the alternator isnt the issue.

What would this be indicative of?

I wouldnt imagine theres a wiring fault in the engine loom as that was removed from my Saxo which was running perfectly. Battery +ve cable or ground cable? I checked the resistance between the battery -ve and the engine block, showing up as ~60Ω.

Thanks in advance.

I'v had similar problem with Peugeot 406, was showing 12.5 on the battery and 14.2 on the alternator. Turn up to be bad connection between alternator and the battery. Just cleaned the connectors and it was fine. (the thick wire from the alternator to the battery)

axsaxoman · 29th November 2013, 16:14

remember the main alt wire connects at the starter motor and then the battery lead goes to starter ,so any or all of those connections could bad
so could the engine earth or even the earth to the body
remove and clean all of them
then you have the power going from the battery to the main fuse box /distribution board --same again check all these

Gabbastard · 29th November 2013, 16:40

Thanks. Ill make that tomorrows task to remove the cables, give them a good clean and reconnect with the usual vaseline as. Ill post up how I get on.