Electrical gremlins.... voltage related

[Cougar]

In post #21 you talk about the voltage being around 2.6 volts and you are not real clear on how you measured it. Was the common lead of the meter tied to ground when you made the measurement? It should have been at least. Check to see if you have 12 volts getting to the stereo while it is hooked up.

 

The small fluctuation in the voltage isn't real bad but it most likely is due to something in the regulator circuit, inside the alternator.

[audio_file]

In post #21 you talk about the voltage being around 2.6 volts and you are not real clear on how you measured it. Was the common lead of the meter tied to ground when you made the measurement? It should have been at least. Check to see if you have 12 volts getting to the stereo while it is hooked up.

 

The small fluctuation in the voltage isn't real bad but it most likely is due to something in the regulator circuit, inside the alternator.

 

yup, ground to ground on body/and neg on batt, pos to "downstream" (towards the stereo) of my inline fuse connection right there at the battery

 

the stereo harness shows 12.8+ volts when multimeter ground is tied to stereo's ground (that i put in, dedicated) and positive lead is tied to dedicated power line from battery - but only when the stereo's harness isn't plugged into the actual stereo (just hangin out there in the dash) when in this arrangement, the 2.6 volts doesn't show up if you do the first test at the battery again.

but, if the stereo unit is plugged into its harness, the measurements at the stereo change (w unit off- because it won't turn on ). if you poke into the stereo's power in where that line is connected, and the neg into the ground just like before, it doesn't read 12.8 volts anymore, it reads . . . ready for it . . ? . . . 2.6volts :-\ so something in the stereo is changing the voltage, clear back at where the power comes into the unit!!

 

i don't get it. and as far as the voltage regulator goes, is that something i can replace (like the brushes) without buying a new alternator or no?

[Cougar]

I am still having a little confusion but I think I got it. The way I understand it, you have the stereo connected up to the power lead and the meter probes measuring the voltage on the leads. The meter shows 2.6 volts. If that is correct there is a high resistance in the power lead to the stereo. You need to move your meter probe closer to the power source to find the problem. When you read the proper 12 volts then the probe is on the other side of the connection trouble. If you are at the fuse connection then the connection is bad.

[screwbaru2]

AudioFile, It sounds like your stero maybe the problem. Have you tried running with the stero unplugged from the car? There maybe a capisitor leaking inside the stero feeding low voltage back to your charging sys.

[audio_file]

AudioFile, It sounds like your stero maybe the problem. Have you tried running with the stero unplugged from the car? There maybe a capisitor leaking inside the stero feeding low voltage back to your charging sys.

 

yeah, its been stereoless for the past few days, the volt meter still dances, especially at start-up- but it doesn't seem to be as bad . . . (the lights don't strobe as much . . .)

like i said, is it possible an issue with the alternator fried the stereo? an issue the alternator still has . . . (?)

 

and can i replace the flux capacitor - - - i mean the voltage regulator in the alternator, or does the whole unit need to be replaced?

 

chris

b.t.w. thanks for all the help so far everyone!

[Cougar]

Your tests show that the stereo isn't getting the proper power input. For a test, you can tie it directly to a power source and then check it out. Your power lead from the battery has a problem. Is is most likely the fuse holder.

 

For the alternator, it is better to replace the whole unit with a rebuilt one.