106 battery light on

mgoodlad · Unread post by **mgoodlad** » 05 Jan 2005, 14:59

Car is 1996 106 1.5d with 98k miles. Not been driven much over the Christmas holidays and parked in my garage. In the last few months on a few occasions there was a slight pause sometimes when turning the key to turn on the car from cold - wondered if the battery was getting a bit weak.
After a week of non-activity the car started sluggishly - switched it off for 5 mins while I closed the garage doors and got ready, and the car would not restart - just a dull click - used another battery and jumped started and the car was fine after that.
Another week passed of not using the car and this morning it started sluggishly, but the battery light stayed on. Opened the bonnet and the alternator belt was still in place and everything looked normal. Had to get to work so drove in with all electrics off except side lights - the battery light sometimes got dimmer and brighter but never off - my instruments backlights got noticably dimmer until after about 20 miles the battery light went off and backlights got bright again - car was fine for for the last 5 miles. Parked the car, switched off and then tried again and started strongly.
As the belt is in place I would guess it is either a faulty battery or faulty alternator. With the signs I have had over the past month my guess is I need a new battery - any other views??
Any help most appreciated.
Regards
Michael
1996 306 TD 78k miles
1996 106 1.5d 98k miles

Peter D · Unread post by **Peter D** » 06 Jan 2005, 15:54

The red light come on when the output voltage is lower than the battery and it goes off when it is higher, how old is the battery as condemming the battery when it is likely that the alternator has not been charging it properly. Run the engine at 2000 rpm and measure the voltage across the battery it should be 14/14.25 volts no load and 13.7v with lots of laod, lights blower sceen heater etc. I think the brushes are on there way out. Regards Peter

mgoodlad · Unread post by **mgoodlad** » 09 Jan 2005, 01:16

Thanks Peter - the battery was getting a bit old so I picked up a new one on the way home and fitted it that night. So far so good. I will do the voltage tests to check out the alternator.
Regards
Michael

mgoodlad · Unread post by **mgoodlad** » 16 Feb 2005, 15:26

Yes, it was the alternator itself - light eventually came on and stayed on. Voltage across the battery when running was about 12v so that was too low. Remanufactured unit from local Autosave for about £70. Not straightforward to fit - not much room and particularly poor access to the top and side mounting bols. But we got there..
Thanks to all to responded.
Michael
1996 106 1.5d 100,800 miles
1996 306 1.9TD 78,000 miles