Technical Alternator Question........again

[BagPuss]

Hi All,

For the last month or so, I've been getting the Alternator light on whilst driving.
The Belt has been change last month and yesterday I changed the Battery and the light still persists.

The other annoying thing is that sometimes it will go out, but return after a few days?

I know most will say its the alternator playing up but upon inspection and checking it hives out the following:-

Engine off Battery Reads :- 12.5V
Running :- 13.9 - 14.4V
Running with all lights on :- 13.9 - 14.5V

So all would appear to be ok with the alternator.......

Any other ideas as to why the damn light wont go out?

Also just in case, how much for a new alternator?

Cheers all.

BagPuss
Cinq Sporting C/w Roofbars & Roofbox

 

[paul_treg]

Hi,
On the back of the alternator there should be a charge signal cable(controls the light on dash), its the thinest cable on its own, I think its black on my 900s, check to see if the connection is good/clean or if wiggling the cable causes the light to come on/go off etc..
Your alternator seems to be working ok with the data you supplied, but were the readings taken when the charge light was on or off..?

Paul T

 

[BagPuss]

Readings were taking with the light still on as it was prior to getting the new battery.

Thanks for the info will double check on this and at the same time check the wires.

BagPuss

 

[MotorWorldChink]

The thin wire can get a poor connection on the alternator if the plug corrodes up. Sounds like the problem i've just had the rectifier is intermittantly faulty. Can just have the rectifier replaced

 

[jjohn204]

Do any of you guys know the proper way to wire the newer style alternater with built in rectifier to the older style wiring harness. Its a 74 124cs. Thanks