Battery Light Blinking Battery Not Charging, Hard To Start

hardmeat

New member
Joined
Aug 31, 2009
Location
oklahoma
TDI
2001 jetta
My Wife Was Driving My Jetta 2001 Tdi And The Battery Light Started Blinking And Then All The Dash Lights Started Blinking On And Then The Car Died On Her,,i Went And Trailered It Home And The Battery Was Dead, So I Installed A New Battery And Altenator, Along With Some New Glow Plugs That I Had Ordered For It...it Has Been Hard To Start When Its Cold...well After Installing All The New Stuff My Battery Light Is Still Blinking On And Off, The Car Has A New Altenator, I Know Its Good Cause I Had The Auto Store Check It Before I Brought It Home To Install, Put In A New 1000 Amp Battery, New Glow Plugs. Yesterday I Was Letting The Car Idle And I Noticed The Head Lights Come On Brighter And Then I Checked The Battery Light And It Had Stopped Blinking, I Drove It Up The Road And Back, Started And Stopped The Engine At Least Ten Times And The Battery Light Stayed Off, That Was Yesterday, Then This Morning I Decided To See What It Would Do, I Went To Crank It Up And If Cranks A Long Time And Then Finally Fires Up...then The Blinking Battery Light Is Back Going Again..lights Dim....anyone Got Any Ideas,,,could A 109 Relay Cause This Problem, Or Any Help Would Be Greatly Appreciated...
 

Kite Baron

Member
Joined
Apr 9, 2006
Location
Central MA
TDI
2) 2003 Jetta TDI's
Check connectivity points

All the lights coming on and then finally stopping was probably the voltage slowly draining down. As the voltage drops, the battery light is obviously first. Second, as voltage continues to drop, the ABS light will come on because the coils won't have enough juice to rapidly pump the brakes. Third, the airbag light will tell you you're getting near the end as there is not enough voltage to fire the sir bag. Last is the rough running showing the fuel pump is about to quit.

On one of my alternator replacements in cold weather, I had the new battery light up after some initial cold start attempts. The light goes out after a short time of charging. This got better after I replaced the glow plugs as long cranking times were reduced a lot.

Check your heavy connections. You already know what a ***** it is to change the alterator. At the end of a long day(s) of getting it done, you might have skipped the wire brushing of your battery terminals, or forgot just one more tightening of terminals, ground lead, or the 13mm nut on the positive lead to the alternator. If you check your alternator, be sure to disconnect the battery first. You don't want to start welding with your wrench. :eek: Try disconnecting and reconnecting the plug on the alternator too. It can sometimes not go in all the way.

Check the voltage at the terminals of the battery when running. Is it near 13.8 volts? Good. If not, check the connections.
 

Ray_G

Veteran Member
Joined
Jul 20, 2004
Location
Tulsa
TDI
98 Jetta TDI
He brought the car to me to look at, after much hassle, two trips to two different places to check the alternator out after taking it off twice because I could not find anything wrong electrically (both the Bosch shop and Oreilly's which is where it came from said it was good..) I finally figured out that the clutch on the alternator was slipping under a load, but only under a load. Anyway the car is charging properly now. I have nothing nice to say about alternators from Oreilly's every time I get one from them it comes off for being defective, at least one time anyway...
 
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