Yesterday my son calls f / school truck won't idle? I jumped it off and by giving itsome throttle by hand at the TB was able to get it to idle. Drove it home w/ the CE light on. Hooked up the code scanner and get P0123. Searched here on the forum, see a post about changing out the TPS and IAC valve . Went ahead and changed both. I did not check voltages, as it was late by the time I did all this.
Truck ran fine last night. This morn. he drove to school, and called me saying that the Check gauges light came on in the school parking lot and his Battery gauge is reading low , won't crank. What's up w/ this?? Any ideas, greatly appreciated. This is all on his '99 Ram 1500 , 5.2 l, Auto tranny. 110K miles. Thanks.

 

maybe alt goin bad?

 

That was my guess too but I don't believe that would make the check engine light go on .

 

hes sayin his check gauge light came on, not cel right rufneck?

 

My mistake [sm=oopssign.gif].

It definitely sounds like your alternator if you have a DVOM you can check if it is good or not but I wouldn't really bother, just take off the negative battery cable , put the DVOM on volts make sure it is DC voltage (correct me if I am wrong, for the thread starters sake) put the negative lead on the negative terminal and positive on the negative batter cable to make a complete circuit and check the voltage, then do the same thing after you start the car up and let the car run to see if the alternator is charging the battery.

 

Thanks for the input, I am thinking alt. as well, but haven't been to the school yet to look at it. The C E light was on yesterday before I changed the TPS and IAC. My son said that the Check Gauges light came on this morn and that it would not restart after he killed it. Thanks for the tip on checking the alt w/ a DVOM , I didn't think of that. I will be going to look at it after lunch. I the mean time thanks and if you have anymore info let me know. Thanks again.

 

Another thought , if it is the alt shorting out. Then it would be possible that the TPS fault "P0123" could have been caused by an over charge in the system due to the alternator , "right or wrong" ?? Just trying to think everything through.

 

Well if it was over charging I think your sons truck would have started up, I honestly don't know so I am going to make an educated guess and say that it most likely isn't but just to be sure after you put a new alternator in it if you do scan it again.

 

Turned out to be the battery, took it up to AutoZone and alt tested fine , Battery was probably still weak from his trying to start it yesterday before we changed the parts in the TB. Anyhow, thanks for the tips and glad this was an easy one.