Help me please !!!!

[Pnutt]

My Alt. light came on this afternoon now my truck will not idel un less I give it a little gas . Could this be caused by the Alt. going out?

Thanks
:Thumbsup:

[slacker]

usually means that the alt . brushes are worn and need to be replaced .. depending on year of your truck ... its a fairly easy job . you'll be running on battery only soon .

[Pnutt]

Thanks slacker but would this cause my idel problem?:Help:

[fourwd1]

Quite possibly.
When your alt isn't charging you're runnng off the battery, and when battery starts running low your coil puts out lower voltage, the ECM won't work right, etc.

[Rescue]

Originally posted by fourwd1
Quite possibly.
When your alt isn't charging you're runnng off the battery, and when battery starts running low your coil puts out lower voltage, the ECM won't work right, etc.

I agree on that one, your surely running on battery alone. Here is a simple test you can do to check if the alternator is not charging. start the truck then unplug the battery. If the engine stalls, the alt is not charging. If it runs after you unplug the battery then your alt is good.

A second test with a multi meter: battery voltage is 12v to 12.6 volts roughly. When your charging the voltage on the battery should be in the 14 volt range. If it is below that your alt is not charging enough and needs to be replaced or rebuilt.

[ZUK]

Originally posted by Pnutt
My Alt. light came on this afternoon now my truck will not idel un less I give it a little gas . Could this be caused by the Alt. going out?

Thanks

Yes.....when your alt light comes on then there is no 'charge' going to the battery.....meaning the engine is getting juice solely from the bat.....if the bat is tired or weak then it will quickly drop to about 9 volts which means the efi system won't like that low of a voltage and the engine may want to stall. Check your brushes.....they cost about 5 bucks

[Pnutt]

Sorry I did not give enough info on my motor it is a 20r carb. does this help

[slacker]

yes definatly ... the guys answered . 20r alt brushes will need to be soldered in ... remove the alt , and dismantel . Brushes are in the holder at the end of the alt . they are spring loaded , so dont loose the springs ... you must unsolder the old ones and then thread the new tail threw the spring and the little hole in the holder . Little trick I do is run the solder threw the hole first then the spring and then attach it to the tail of the brush and pull it threw ... works like a charm . leave most of the brush sticking out of the holder and solder the tail and cut off the excess . Push the brushes into the holder and using a piece of mechanics wire , push threw the holes in the holder to hold the brushes back . leaving about an 1" of wire sticking out .

I also suggest to take a piece emery and clean up the armature (where the brushes ride on) ...... then put it all back together carefully putting the back on over the mechanics wire 1st . when holder and armature are in place ...then you can pull the mechanics wire out the back and seat the new brushes . and then just put it all back together and install ... viola .
hope that helps .

[Jeff S.]

The brush needs to be soldered in at a specific length so when the brushes wear down they can still contact the armature. I believe it is around .415" or so. If you have a manual it will be in
there.

Jeff S.