Jbolt001

My check engine light came on today while driving. Oil pressure is fine but the battery/volt indicator was below the 1/2 mark. I checked the battery voltage when i got home. the battery while the engine is running shows 12.35 votls and 12.68 when off. I'm guessing there is a problem in the charging system somewhere or ???? Electronics is not my strong point but I usually grunt my way through these things with a little dirrection. <br><br>What should I check first? I don't have any manuals either so be specific.<br><br>Any help would be greatly appreciated.

Superduty12v

The SES light could be a number of things really. With the newer trucks you need a scanner to determine what the problem is. But scanners are about $2,300.00 unless you can find one specially for your truck. 12v's shouldn't set the SES light off.

Alan_Reagan

OK, I see this post now. I'm wondering if your grid heater relay is stuck on. This will cause the battery voltage to remain low and probably a check engine light due to the low voltage. Disconnect the grid heater lines and see if that solves your problem. Remember, it will take three successful cranks without the problem to extinguish the light.

Lil Dog

I hate to flog a dead horse, but the crank sensor on the truck may be going south... There is a crank shaft sensor on the front of the engine looking down at a notch in the harmonic balancer. There is a three wire connector at the top just behind the rad hose that may have some dirt in it or the sensor is going south. <br><br>The crank sensor on these years of rigs tell the computer to engage the charging circuit.<br><br>If you haven't unhooked the battery yet after this code came on you can read the code off the truck.<br>When the truck is warm and shut down.. Turn the key to the on position ( NOT Start) and off 3 times and finishing in the on position. Watch the Check Engine lite and write down its flash codes. It will flash a number of times, pause then flash another bunch of times. The flashes will be in groups of 2, like 1 - 2 or 5 - 5. After you have these codes, call your local Dodge dealer and talk to the service guys and they can look up the codes to tell you what is wrong.<br><br>I still have a hunch its the crank sensor..<br><br>J-eh

Jbolt001

Here is the fault code just in case anyone here might know what it is.<br><br>1-2 4-1 5-5<br><br>Thanks for the help so far.

Jbolt001

It is amazing what you can find online these days. First google search resulted this from allpar.com<br><br>Code<br>12 = battery or computer recently disconnected<br>41 = Alternator field control circuit open or shorted<br>55 = End of codes<br><br>41 Seems to be the key to this. Only if I new what to do next.

Lil Dog

Ya know I never would have looked online.. Who knew???<br><br><br>Well as for that code, it could be the alternator is toast or the crank sensor.. I don't think the computers in our year had a code for that yet... Not sure. ??? ???<br><br>J-eh

Jbolt001

Is there a way to test the alternator or CPS?

yomitch

on the alternator you will find 3 terminals. One main terminal with the big wire (which charges the batt and accessories while driving) and two smaller terminals which are the field terminals. (this makes the electro-magnet on the rotating part of the alternator to create electricity) This is an assumption of mine and don't take this as gospel but one should be +12v dc and the other one ground. so with the ignition turned on but without starting the engine see if one of the terminals is +12 volts and the other 0 volts.

Jbolt001

Thanks everyone! Turned out to be a shorted field winding. I now know more about alternators than I care too. <br><br>It is amazing how much information you can find on the internet.<br><br>Thanks again,<br><br>J