308 "G" light poll....

Only when the engine is at idle??

 

Sorry, I can't do a poll and I don't think it would help anyway.

Check the alternator belt for correct tension; it may be slipping.

Also, check your idle speed. It should be between 900 and 1100 RPM.\

And, to add another foible that occurs with F-car ownership, check for a bad ground. Very common in Ferraris.

 

I have a rebuilt alt, and my light glows dimly when I hit the brakes as well. It doesn't come on when I use turn signals or lights though.
Jim

 

So Greg you're beating this to death. You have had a few posts on this subject and with all of the answers pointing to the same thing you still can't comprehend . So here is a way to fix it. Disconnect and jumper out the G light. Problem is fixed.

 

Steve, please, you're really wrong. I mean, analagous to your advice here, it's like your solution for a subdural hematoma is to take Iboprofen (i.e., treat the symptoms). Take the jumper out of the G light? Jeeze. If it makes you feel better, sure. I wouldn't buy your car though... I don't mean to be firm but I just don't agree with your advice; in fact, I know it's wrong.

What greg should have done was get a digital multimeter (DMM) and check the voltages before he got the VDO voltmeter, the latter is a monitoring instrument while the first should have been used for troubleshooting by testing voltage at the battery or in the current socket under different circumstances. No worries though.

He comprehends fine and with all of our help--yours included--he'll arrive to the solution.


Signed,

"No G light under braking" Mike

 

By the way Greg, at this point you really have no idea as to the validity / calibration of the VDO voltmeter. Mine reads .2V or so low. Please get a digital multimeter from Radio Shack and do your testing with it--a far more accurate instrument.

 

Well I'm sorry guys but I was under the assumption that all of the standard checks were done. You know like bench test the allternator , verify good ground , verify no shorts , verify battery is up to voltage and holding charge. You know dumb things like this. If you don't do your homework you won't pass the test. You don't need to go through the process to install a volt meter to check all of this out. I assumed some common sense here but I guess not. This is basic autoshop 101. By the way the G light starts to glow at 12volts so at idle (1000 rpm ) the alt will hold 12v when you have the AC or wipers or directionals on so at night you will see the dull red. This is not a chevy or ford alt that puts out 14v at idle. I believe the peak voltage for this unit is 13.7 at around 2000rpm. When I finish some investigation on the newer type alts I'll do a conversion to a new 80-100amp. Also be able to get rid of the thin belt.