alternator/charging issues - wire/rpm, etc

[robz]

hi,

on my 91 jetta diesel 1.6 (non  turbo),
recently I have my battery has died while driving and when boosted - it would only run for a couple of minutes then die.  I found out that my battery was dead, I bought a new one.  Same thing is happening, went to a couple of shops to test the alternator but the machines were either not working or the guys were unfamilar with how to use the machine... (crappy tire).

so the the red wire on the alternator that is crimped to the the blue wire which is connected but by the nut on the alternator has been disconnected... - now does that only control the rpm gauge or does it also charge the battery, - ever since disconnection the rpm gauge has been not working, did I screw up everything by leaving that blue wire disconnected or?

please help me out,

thank you,

robz

[jtanguay]

i believe that wire you're talking about is the exciter wire... the alternator will NOT charge without it.

sounds like you just have a wiring problem.  your old battery is probably still good.  best to check all connections (alternator, starter, etc), and clean them with a wire brush, and then use some dielectric grease to keep this from happening again  :wink:

the worst spots for corrosion are the positive terminals.  has to do with chemistry and the oxygen molecules...

[robz]

hey, thanks for the info, but does the exciter wire control the rpm gauge as well, if not how do i get that working again.


thank you,

rob

[lildevil]

there should be three wires from your harness , blue/exciter, red/power and red/black stripe goes to your W in the alt, which intern goes into your cluster making your rpm work

[robz]

hey,

cool, thanks for the info, I was totally not looking at it properly, but that is it... I got it all, now I think the alt is just toast...

robz