81 diesel not charging

[auag]

on my 81 diesel pickup i noticed its not charging...the indicator light in the instrument panel doesn't come on..even with the key on and the engine off..is there a relay or something for the charging system?

[mtran]

1. test/change the indicator light.
2. next bad rotor in alt

[wmasscaddy]

Check the 5 amp (brown) fuse marked "radio". It powers the instrument cluster. If it's blown the alt light won't come on and it won't charge.

[auag]

another thought...someone has eliminated the plug at the alternator and used female spade terminals..it has 3 wires...2 big red wires and one smaller blue wire...i'm wondering if they crossed the 2 big red wires..do they both go to the battery or is it possible to have them crossed?...

[82vdub]

Have you tested the output of the alternator (or brought it somewhere) to verify that it is functioning properly? It could be a wiring issue, but it's best to know that the alt actually functions like it should.

[auag]

the blue wire doesnt have any power going to it and the dash light doesnt come on when you turn the key on

[Fatmobile]

Did you check the 5 amp fuse mentioned?

[auag]

yes i did...the fuse is good...i'm guessing the next step is check the bulb and then check for a break in the wire somewhere

[auag]

thanks for the help guys..it was the regulator causing the problem

[Fatmobile]

Did you replace it or just give it a better/cleaner ground connection?

[auag]

i had a spare one so i just changed it..but i think your right...the reg was missing one of the mounting screws...probably wasnt grounded good

[82vdub]

Glad you figured it out. To know if the charging system is good, you have to know that the alternator is good.

I've had the regulator come off the alternator on ole 82 a couple times, and I've found that since the regulator loses it's base grounding voltage, that it simply goes to max output and bakes the battery. This happened on a trip back from Texas once.

[Fatmobile]

Mine started losing it's ground on a trip home from Wisconsin,.. the voltage kept going down.
I fixed it ans was lucky enough to be able to push start it.
Voltage gauge saved me that time.

[82vdub]

the voltage kept going down.

Interesting. I guess I have to say that I don't know what the voltage was, but I do know it baked the battery on me twice when it happened. Maybe different style alternators/regulators where one overcharges and the other undercharges??

[mtran]

The accu must be good to charge.If not you can charge but it didn`t hold-do not have capacity.
Bad accu charge at 13.5 V,with same alternator/regulator on good one you get 14 V after 10 minutes.
You can have 70 Ah (or 600 CCA) but in fact you have 40 Ah.
Big thing is that accu make sulfate inside from day one of use.
I try this for that but it helps ONLY to not so old/sulfate one,and it work,just doit from time to time-before winter is must.
http://www.goldismoney2.com/showthread. ... ba148ba3d2
Yes it use 110/220 v AC but don`t worry it put 13 V DC to accu.
Here,you can`t buy good NEW accu,Vaeta or Bosch etc.
Today they make them to last 3-4 years at max.