Failing Alternator?

Author
Discussion

MajorClanger

Original Poster:

749 posts

277 months

Friday 4th January 2002
quotequote all
With the winter loads on the car I've been having problems with the battery running flat. The battery recharges fine from a mains charger and has been checked to be healthy. However, last night whilst driving home, the headlights went dim, the radio sound disappeared and the engine started losing power. Also the tachometer reading went to zero (so I'm assuming loss of power to the spark plugs) and the engine started misfiring and didn't want to pull at all.

Is this symptomatic of the alternator failing? I get no other warning lights (actually no lights at all!). Is it a simple case to see if the alternator is producing 12V with the engine running or are there other things that I should I check?

Any help would be appreciated.

MC

PS It's a Citroen ZX (10 year old car, 1 year old battery!)

Paul V

4,489 posts

284 months

Friday 4th January 2002
quotequote all
Test at the battery with a volt meter, check the voltage should be around 12-12.5v then start the car rev it a little you should have 13.5 –14.4v, if not its time to change the alternator, if its ok try with the lights and heater on, you should have above 12.5v.

MajorClanger

Original Poster:

749 posts

277 months

Friday 4th January 2002
quotequote all
Thanks Paul

kevinday

12,287 posts

287 months

Friday 4th January 2002
quotequote all
If you have very low volts at the battery it may be just that the battery is dead.

MajorClanger

Original Poster:

749 posts

277 months

Friday 4th January 2002
quotequote all
I had the battery health checked and the condition is good and it takes a full charge (it started the car OK on Wednesday when it was -9 C). It's a Calcium battery so not quite the same problem with Lead Sulphide deposits taking out a cell on a lead/acid battery (incidentally I saw that can get cell rejuvenating tablets that remove this, but you have to keep using them - haven't tried them myself so would be interested to hear others' views) and also guaranteed for the another 2 years.

I'll check out the volts and obvious things though, doesn't hurt to double check.

MC

Jason F

1,183 posts

291 months

Friday 4th January 2002
quotequote all
I know a great Auto Electrician in Southend if you are interested. If the Alternator has gone he can repair it. If it isn`t the alternator he will find and rectify the fault. I use him quite a lot ( I do have TVRs !! )