99 Ram 318.
Started acting up today, will start fine, idles steady but I can tell it is just a little off. I can rev the engine up and everything seem ok until I step on the brake to put it in gear. It hesitates and dies anytime I step on the brake, or turn on the lights. Battery voltage is 12.5 and is under a year old. Withtruck idling, battery is being charged at 14.4V. Suspect the alternator isn't putting out enough amperage to handle the load of the lights. I can however run the a/c, radio, and interior lights with no problems. I am not sure what kind of load that is compared to headlights or brake lights. All battery connections, alternator connections, and cables look good visually. Any other ideas or things to check before I take it to autozone in the morning to have the alternator and battery tested.

Thanks

 

what happens when you step on the brakes, or turn on the lights while the truck is off? turn the ignition on and monitor the voltmeter while you do this, there should only be a mild decrease in volts.

this is an interesting problem. nothing jumps to mind immediately that makes sense in this case. if there was a problem with the light circuit (and primarily the rear lights since it happens with the brake too), you should blow a fuse. even if there was no fuse, you should burn through a wire before your truck stops running. keep us updated.

 

Checked again, battery voltage is down around 12.1 but I think all my playing around has drained it a little. Turning on the ignition key, but not starting the vehicle,drops it down around 12.0, and turning on the headlights, or hitting the brake pedal drops it down to 11.7V. Turning ignition key off it climbs back up around 12.1V. Maybe the battery is bad again, when I changed it last year, the truck was running so bad I thought for sure something else was wrong, but it turned out just to be a bad battery.

 

i think at this point your best bet would be to pop a new or known good battery in the truck and see if the issues persist. doesn't seem like anything else should be wrong with the truck. 14.4V is an ok charging voltage, but if it creeps higher than that while driving and you don't notice, thats bad also. overcharging can hurt a battery in the long run too.

 

Well went to autozone this morning to get the battery and alternator checked, both were good. It ran like crap the whole way there, barely could keep it running. Was having to shift to neutral and keep on the gas to keep it going. It revved up fine, but had no power like the cat is clogged. If I remember correctly last time I had a clogged cat in my old car the engine would barely run, my truck rev's good now and as good flow at the tipsso I don't think that is it. Although there was no check engine light on I had them check for codes and I got P0171 "bank 1 too lean." Whats weird is after messing there for a while and the truck having a good chance to sit there idling and warming up, it ran much better on the way home. It did seem to surge though, touch the gas and it would jump up to 2K rpm, and then settle back down. I am still not convinced this isn't some sort of electrical problem though, my turn signals are acting weird, flash fast then slow then steady, not sure where to go with this one. Hoping to avoid a trip to the dealer!

 

i dunno if this help but on my truck when i step on the brake and shift into drive the locks lock. If you have this feature the lock may be shorting out or someting

 

Well, if anyone is reading this with a similar problem looking for answers I can't be any help for you. My problem seems to have magically cleared itself up. The only thing I can even consider the culprit was it was pretty low on gas, and it was extremely cold the night before. Don't know if maybe some water in teh tank froze up, maybe some kind of vapor lock. Filled it up with some good gas and some quality techron fuel system cleaner, and it has been running good for a few days now. I would have rather spent some money on fixing a problem and knowing it was fixed than have the chance of this thing coming back when i'm a 100 miles from home. Maybe its finally time to join triple A! Thanks for the help.

 

Ok, well back to square one. Ran good for a week now but the same problem is back. I had been driving the truck no problems, stopped for about an hour, and got back in and as soon as I step on the brake to put it back in gear it dies. Same symptoms as before, headlights or stepping on tne break will kill the motor, once in gear and revved up it runs ok, but will sometimes miss. Also, the turn signals flash quickly when turned on, not convinced its not some sort of electrical problem instead of fuel problem. Anyone ever experienced something similar? Any info is much appreciated.

 

usually the turn signals will flash quickly when there is a bulb out. This is to let you know as a driver that a blub is out. I think you must have a crossed wire that sometimes touches and sometimes not. Must be where all those systems meet or in the same harness. I hate electrical what a pain in the ***. I has same deal except mine would blow bulbs and fuses all the time, that turned out to be a crossed wire too. Could also be a poor ground connection somewhere.

 

Mattyge, You give me a good idea, I will pull the fuses for the turn signals, headlights, and brake lights and see if the problem clears. I will let you guys know what I find shortly.