charging problems

[turbopwer]

I just bought a new battery and I had the altenator checked and new bearings/bushings put in (120 amp). The scanmaster says 11.2 then 11.9 the 10.6 so its jumping around and the car will not start back up unless jumped. Just got home from taking the altenator back to the starter/alenator shop and they double confirmed and showed me it was fine under load. Now they did install a new chrome shell that I brought to them and the pulley was slighly smaller so I had to get a smaller belt but that should not affect anything.They want me to bring it back in with the car. Can anyone give me some possible things to check before driving the car to tem? Also, on a side note my scanmaster works fine except it does not read MPH why?

 

[azbob]

Sounds like the famous volt light failure that can be checked by turning on the ignition and looking for the volt light on your dash. The light bulb is in the circuit with the exciter circuit for the alternator. No light...no volts.

 

[Red Regal T]

You have to loosen your speedo case and move it around until you make proper contact and the volt light comes on with the key turned on, engine not running.

 

[The_Six]

Go to auto zone by a new alt plug run a 12volt switched power source to the F wire that will bypass the volt light circuit. Do not reconnect the L wire you can only have one wire connected or you will fry the alternator If it fixes it you can leve it this way but I would get a good volt gauge if you do. .

 

[turbopwer]

Are you all basically saying if the volt light is not working the alt. will not perform like it should? Can someone explain this in a more electrical for dummies style?

 

[87gnguy]

I just went through the EXACT same thing last week. My volt light wasn't coming on when the key was switched to the on position. Fixed the light, fixed the charging problem.

Sounds like the famous volt light failure that can be checked by turning on the ignition and looking for the volt light on your dash. The light bulb is in the circuit with the exciter circuit for the alternator. No light...no volts.

 

[wbzautocustomiz]

get the caspers field fix plug and play best $40 bucks you will spend

 

[Red Regal T]

Are you all basically saying if the volt light is not working the alt. will not perform like it should? Can someone explain this in a more electrical for dummies style?

Yes, it is that stupid and the electrical engineers at GM thought of it.

 

[delcowizzid]

even with no alternator light it should still start charging after a decient free rev on the other hand if the other sense wire isnt flowing 12v it wont start charging.easiest way to test if they are working is unplug alternator plug turn ignition on and all 3 wires at the alternator should have 12v or battery volts just incase you have drained battery and its not at 12v

 

[turbopwer]

Dash lights are out so the fuse may be bad which Im sure it is along with the bulb. I ordered the Casper's piece today so I don't have to worry anymore.
Thanks

 

[turbopwer]

The Caspers fixed the charging problem but all of my guages ie. volt light,service engine soon light, /tach/boost lights, and so forth still do not come on? I checked all of the fuses an bulbs and they are fine.