My truck is kicking my a$$...If I turn the ac on max and turn on the head lights the battery discharges (voltage keeps dropping) It's no the alternator and I jumped the battery temp sensor with a 15k resistor so the truck thinks the battery is really cold..not that..maybe a power drain but it's not blowing fuses...uggggg...any ideas? Its a 2002 1500 slt with auto transmission and a 5.9l engine

 

Welcome to DF. First, before anything else, please read this.

What model year of Ram 1500 do you have? Engine size? 4x4 or 4x2? Tire size? Trim level? Etc. etc. All are important. After you tell us that stuff, I can move you to the appropriate help section.

 

DUH! Sorry, It's an 02 4 door 1500 slt with a 5.9 and auto transmission...

 

I will move it to the 3rd gen section. If you don't get any good answers there, post your question again in the 2nd gen section. 2002s had the interesting characteristic of having a 3rd gen exterior and a 2nd gen drivetrain and interior.

 

thanks jason.. I have been fighting this problem for years ,,so far I have just worked around the problem as it only really shows up at idle under high load conditions..like during rain,in the summer ...headlights on and defroster or ac ....sitting at a stop light..etc...It is driving me nuts!

 

Ok, so we assume you had the alternator tested because you said it wasn't that... It sounds like a battery, an alternator, or wires. If you have AutoZones around you they usually can test the battery and alternators for free. Also check out the battery cables, making sure they have a good, clean, and tight connection. You always want to stay on top of those. I heard that if they get a lot of corrosion, sometimes the corrosion can actually start eating away inside the cables and cause headaches. Also if you go to AutoZone they can check for any check engine codes which might give further insight. Hope you get this figured out soon.

 

You could put a meter in line with either the + or - with nothing going on to see what the draw is. Pull fuses 'til it drops to near 0. Keep doing that 'til you've identified all the power grabbers (some will be normal - the clock and 'puter, for instance). DON'T turn on any high-current devices! That'll cook your meter or blow its internal fuse. Done there, been that.

 

Does anyone know what the alternator puts out at idle?

 

It depends on the load on the system. With everything off, it should be around 14V. With lights, blower, wipers, etc running, it will drop at an idle. It should stay above 12V, but it depends on idle speed. You could always try to find a smaller alt pulley. This will spin it faster at idle speed and help keep the voltage up.

 

No I meant the amp output..something else that the truck does that may or may not be related is,,,,when you turn the ignition key to acc the power windows work but the windshield wipers do not...It that not backwards?