97-12v

my voltage is fine unless i really get down on it and it dosn't charge as good only about 13 or so and when it is warm dosn't seem to charge as good, but if i go out in the morning and crank it seems to charge at 14 or a little over. 97 4x4 diesel 2500 excab

wcbcruzer

Alternator going bad? I'd start by checking all the connectors and wires for corrosion/breakage.

schoust

I have a simeler problem with my 95 every once and a while when I start her up in the A.M. it seems like there is some sort of problem with the charging I have to hold my foot on the peddle or it will stall,when looking at the charging meter it's lower than normel than all of a sudden it will pick up and start charging??? What gives with this?? Sorry did not mean to steal your thread.....

DL1221

After you clean off all the corrosion from the battery cables, check the voltage at the batteries with a digital multimeter, with the engine running, it should be between 13.5 and 14.5 volts, the dash volt gauge may not be that accurate.

If your battery voltage is below 13.5 volts, then it is too low. The PCM regulates the alternator's output voltage, using the engine speed sensor (is your tachometer working OK, if not then the RPM sensor is bad?) and a battery temperature sensor, among others. So your problem could be the PCM, a bad sensor, or a bad alternator. Your local auto parts store should be able to check the alternator for you.

The only exception is on cold start-ups, when the grid heater cycles on the voltage will go way below 13.5.

wcbcruzer

That sounds like the grid heater kicking in.

schoust

No it's not the grid heaters I'm familiar with how they work,when this happens the truck won't stay running unless I have my foot on the gas?? Seems like the alternator just won't produce any juice then all of a sudden wham it starts working normaly again??Maby the alternator is starting to take a crap???

TxDiesel007

Seems like it

id check the alternator, id seriously rule out the PCM tho but it is possible that it can be goin bad, Do the simple first, batteries, starter, alternator, if they all check out, then i cant help ya

I know my grid heaters kick in and off and it does take a toll on my batteries when they do,

Perhaps one battery is goin bad?

Rick

Dr. Evil

Whats your idle set at ??

displacedtexan

Schoust-

Also how long till it wil idle without pedal? If it is below freezing I have to give mine pedal, but only for a seccond or so...

schoust

My idle idle is a bit low I had to make a little adjustment after a 3 k gov. spring kit install. I know it's not the grid heaters I am aware of these and how they cycle up here in the Northeast I found that out quickly,I think that was one of my first questions here on this forum. I believe somthing is wrong when you start your truck and the alt. indicator is very low and then all of a sudden bam it starts to operate normaly. I just would like to nip this in the bud before the real cold hits....

infidel

schoust, if you are using batteries with a spacer under them or shorter batteries and the battery itself isn't in contact with the battery temp sensor alternator output will be low when cold. PCM thinks the battery is frozen and limits the charge until under hood heat after warm up tricks the sensor.

schoust

Hmm thats interesting Bill I'll have to check that would that actually cause what's happening? It only seems to last a few secounds then it will kick in and start to charge??