Kev Rayner Posted September 7, 2001 Share Posted September 7, 2001 Hi, Can any body help ? I have just changed the Alternator on my Seven and the ignition light is constantly on. Before I change, the ignition light would go out after I had started the car but glow brighter the higher revs the engine was turning over at. All the help I received said “I needed a new Alternator” but now I have fitted it, the problem seems worse dose anybody have any ideas in what might be wrong ? Thanks Kevin Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted September 7, 2001 Share Posted September 7, 2001 Did your ignition light work properly before? Is the light on when the engine is off, and when it's running? You've almost undoubtedly got an earthing problem somewhere. When the engine is running, one side of the ignition light is recieving a +ve feed from the battery, and the other is recieving a positive feed from the alternator. Net result is two +ve feeds to the light - ie not current flow - ie light goes off. For the light to stay on, one side must be acting as an earth. Alex Link to comment Share on other sites More sharing options...
Big Brother Posted September 8, 2001 Share Posted September 8, 2001 Had this a while back on a "new" alternator. Checked everything - all seemed OK Swapped the alternator out and problem disapeared. Turned out to be a faulty diode pack on the alternator. Steve cool.gifScream...if you want to go faster!!!id=limegreen> cool.gif Link to comment Share on other sites More sharing options...
Kev Rayner Posted September 8, 2001 Author Share Posted September 8, 2001 Hi Alex, Thanks for the advice, Yes the ignition light worked properly before. The light is off when the engine is off and on when the engine is running ! Any ideas where to start to look for the earthing problem, would it be worth checking to see if there is any current flow from the alternator ? Thanks Kevin Link to comment Share on other sites More sharing options...
Nigel Riches Posted September 8, 2001 Share Posted September 8, 2001 Kevin, have you checked for a good circuit on the main alternator to battery lead, ie very low resistance, I had a similar fault some years back, and when the main feed wire was replaced the fault cleared, the original wire had aged, probably in the area of the exhaust manifold, and become high resistance, so no charge, and ign light on. Hope this helps. Regards Nigel. Link to comment Share on other sites More sharing options...
elie boone Posted September 8, 2001 Share Posted September 8, 2001 Kev.If you disconnect the small wire at the back of your alt.(contact on) and the light goes out, it is a faulty alt.The small wire must be connected where it is marked DF (check this first!) Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now