TheSamba.com :: View topic - Alternator problems mabye? Still having weird issues

Tue Nov 03, 2009 1:51 pm

symptoms: I'm getting the gen light on right after 1st startup of the day
When not using headlights I everything electronic works great, car idles great and runs fine.

At night when I use the headlight if I'm not on the gas the headlights will dim and the gen light will faintly glow.
Also my turn signal light on the dash will stay on while activated, and I'm pretty sure the lights themselves freeze on at the same time.
While driving at 60mph for 30 miles my gen light will still glow dim with or without the stereo, but only when I have my brights on.
When starting up, the car idles rough for a bit and the gen light will come on/off while reving the engine.

I had issues with my auxiliary air valve and vacuum leaks a few months back. I've replaced ALL vacuum hoses, didn't do any of the fuel hoses because they got an overhaul last summer. Did check all hose clamps and state of hoses, both vacuum and fuel. My air valve was dead on with the multi-meter and I tested it's opening and shutting with the freezer/toaster oven. After all that it still tests fine on the multimeter and seems to function fine. Also followed the bently manual on testing the air flow meter and other FI components with a multimeter, all ok, even from a cold engine startup.

Pulled the plugs and they're fine. Did notice an unusually fast buildup of carbon on distributor cap and rotor (both bosch and a petronix electronic ignition. Bosch blue coil, etc...very standard setup besides the electronic ignition.

I pulled the injectors out and tested them for leakage, even the cold start valve, none there. The seals look fine on all the injectors, replaced those about 2 mabye 3 years ago and still look new.

Engine is about 1500 miles past last oil change and valve adjustment. From the sound after warmed up it sounds/feels fine. (no clanking valves, normal vw sounds)

I tested the alternator when the gen light was on and it was producing proper voltage, by the time I got to the battery to see if it was charing properly the engine is warmed up more and the gen light goes out.

To the point...I don't want to drain my battery (if that's actually happening) while driving at night. And I like to use my stereo, headlights, and turn signals at once without the gen light coming on.

I know it's not overheating, that's for sure.

Any ideas? Possible resistance in the wires causing it?
I'm thinking about replacing the alternator anyway before winter. I definately don't want a dead battery, and have read in it's owners manual and other manuals not to jump start a dead battery on a FI bug.

Tue Nov 03, 2009 2:22 pm

jhvw1976 wrote: Possible resistance in the wires causing it?

Wire and terminals. Not much you can do for the wires unless you replace the ends, but you can go through the car and clean all the terminal connections. This should help greatly. A tip I've heard but haven't done myself is to solder the fusebox connections together. If you do a search for it, you should find it.

Tue Nov 03, 2009 2:34 pm

Load test your battery, it's possibly weak. It is strong enough to get it started, but the voltage is dropping low after startup and your alternator is overworking itself to charg back up. This could kill your alternator with time too.