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OT: Need auto troubleshooting help

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  • OT: Need auto troubleshooting help

    Paging all auto mechanic gurus...

    We have a 2003 Dodge Grand Caravan, and when my wife tried to start it this afternoon it was dead. The battery was nearly flat and there is a continuous clicking coming from the throttle body,even with the key out--thus the dead battery. I was thinking something along the lines of a failed throttle position sensor, but why on earth would it continue with the ignition off/key out?? Is it possible that the battery just crapped out and the extremely low voltage is somehow causing the clicking? Weird stuff--any help would be greatly appreciated, as I try to steer clear of the local dealership as much as possible. Thanks, Rob.
    Last edited by sidegrinder; 06-27-2009, 06:12 PM.

  • #2
    Original battery?? If so 6 years probably is about all its good for. If not the original, then I would have the battery tested on a good load tester and go from there. As to the clicking noise I can not advise ,but if a battery replacement or a recharge cures the clicking all would be OK. JIM


    • #3
      Yeah Jim, maybe I'll get lucky on this one--fingers crossed. It's been quite hot here lately and I could understand the battery dying. The clicking is kinda strange, but we'll see after I get the battery somewhat charged. Thanks!


      • #4
        I'm not familiar with Mopar stuff but good battery voltage is must before ANYTHING else. If you still have the clicking after you get the battery up to snuff, I'd suspect a relay somewhere with stuck contacts or a fuse blown that causing a feedback across a circuit or two. Start at the top, easiest stuff 1st then get more technical. I can't tell you the number of times techs will dive in head first looking for exotic solutions and the bottom line is a dead battery, corroded terminals, blown fuses, wrong bulbs installed in a socket, etc, etc.

        If you don't find it fast, type the symptoms into Google and start hunting. Good luck!

        "Accuracy is the sum total of your compensating mistakes."

        "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton


        • #5
          Originally posted by sidegrinder
          I was thinking something along the lines of a failed throttle position sensor, Thanks, Rob.
          Throttle position sensor ????

          You have an electric right foot ?


          Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.


          • #6
            Well if proper battery voltage doesn't cure, it looks like it may be a sticking fuel pump relay. My inner google child indicates that parisitic losses from this are not uncommon. Thanks again.


            • #7
              Usually extremely low battery voltage will cause all sorts of electrical feedback. Best way to proceed is first address the dead battery. A fully charged battery will make diagnosing the problem much easier.
              A throttle position sensor doesn't even come into play, since it is an input sensor and operates off of reference voltage supplied by the computer.
              Basically, a throttle position sensor is nothing more than a rheostat that varies the reference voltage the computer sees at that terminal.
              The clicking at the throttle body is probably the Idle air control motor trying to go to the "RESET" position, and is unable to do so because the battery is dead.
              You might want to call your friendly Chrysler dealer and ask if there are any service bulletins or recalls on your '03 Caravan. I seem to recall something about electrical problems burning several of them to the ground. Check out this web-page:

              Let us know what happens after you replace the battery, OK?
              No good deed goes unpunished.


              • #8
                Well after a few hours charging I was able to start the van fine. The clicking returned as soon as I reattached the battery cables and continued whether it was running or not, key in or out. I pulled the fuel pump relay and the clicking stopped, so I've temporarily swapped it with a sister relay for the parking lights and all is fine. Apparently the relay stuck shut and drained the battery over the course of 30hrs or so as this wiring is, for whatever reason, independent of the ignition switch. Now if only I could get back to the saturday afternoon nap SWMBO so rudely awoke me from at the start of the excitement Thanks for the help, Rob.


                • #9
                  Originally posted by sidegrinder
                  Paging all auto mechanic gurus...

                  We have a 2003 Dodge Grand Caravan, and when my wife tried to start it this afternoon it was dead. Thanks, Rob.
                  Rob, We have an 02 Chrysler Town&Country basicly the same vech. I believe.
                  Wife tried to start it click,click,click nothing. Put bat on charger and replaced badly corroded pos. cable end.
                  Full charge ,fixed cable , put key in ....and nothing. Pulled and checked fuses,relays,ground conn. Still nothing, I pulled the positive lead just in case I had a slow drain somewhere and called it a night.
                  Next day after work I hook up the cable and the head lights come on, but van still will not start. O.K. I jump to the conclusion that I have a bad head lt. sw. and the drain on the bat. and My wife cranking it over for who knows how long injured the computer.
                  I remove the headlight sw. wich requires almost total removal of the dash, hook up the bat, put the key in and...the headlites come on(I am holding the switch in My hand) Now I notice that the radio is not working so I decide to see what else is amiss, If I turn on the fan the radio would come on.
                  I gave up for the night , again disconnecting the bat. Van had to sit for a few days befor I had time or energy to get back to it. I connected the cable and for grins turned the key and it I'm pissed that it works as I have not done or found anything yet but the headlite sw. I put it back in and all is well with the whole van .
                  Idrive the van all week end ,every time I got in it , it started and ran fine... except the check engine lt. come on and stays on. I had a friend with a code reader determine that (I considered torching it) the battery has been disconected within the previous 50 starts!
                  Now I can't get the computer to reset and get the lite off, but everything else is peachy.

                  My story kicked Your story's butt .



                  • #10
                    Sounds like you found the problem, for future reference with typical "clicking" sounds when trying to start a vehicle with a low battery the most obvious is what I call "amperage cycling"

                    We've all heard that familiar click/click/click when trying to start a vehicle with a low battery but not everyone knows what really causes that - but in fact its actually a simple explanation,
                    All your dealing with is the battery having enough voltage/amperage to operate the starter solenoid but not enough to operate both the solenoid and the starter -- the solenoid engages and then for a split second engages the starter which in turn robs so much amperage that it surpasses what it takes to keep the solenoid engaged so it kicks out but as soon as it does it disconnects the main amperage draw of the starter --- as soon as this happens the solenoid now has the battery all to itself again and it then re-engages ------------- so you basically sit there and cycle the solenoid in and out and the starter doesn't even get to engage --- click/click/click is all you hear...
                    By the way, when you do this (even with a low battery) there is an extremely high demand on the solenoids contacts and you can actually burn them out (or fuse them together) --- so if one ever hears the sound - don't keep making it happen or you could go from just needing a simple charge to having to replace parts...


                    • #11
                      Is your ignition switch tumbler worn to the point that your wife is pulling the key out before passing the IGN position?

                      I have a saturn that I can pull the key out in all positions due to key cuts and wear.



                      • #12
                        Clutch--key is fine. We've had the van out a couple times now and driven a good 60mi. I will periodically check the battery voltage for drawdown, but everything seems good for now.

                        Steve--your story did beat mine! Lucky you

                        Have fun!


                        • #13
                          Originally posted by sidegrinder
                          I will periodically check the battery voltage for drawdown, but everything seems good for now.
                          If you have access to a multimeter that is able to read milliamperes put it in series with one of the battery posts and the battery cable.
                          Make sure that all interior lights are off and you should be able to see what the current draw is on the battery.
                          You should have about 20 to 50 milliamperes of background current draw from the radio, clock, ecu, etc. Anything much more than that and you have problems elsewhere. To narrow down possible drains to the electrical system pull fuses or circuit breakers one at a time to isolate the circuit from the system.
                          Home, down in the valley behind the Red Angus
                          Bad Decisions Make Good Stories​

                          Location: British Columbia


                          • #14
                            Very good Willy, I go the same route but I get the alternator involved first by disconnecting it while watching the meter (if there's any draw) ---- Many times alternators are to blame due to diodes going bad and backfeeding, as if its not tricky enough they can be "temperature activated",
                            anotherwords they can actually behave normal till they heat - or cool --- nice...

                            After an acceptable draw range is verified then its time to start looking at the battery, for this you should give the battery a little time to stabilize after charging or running the vehicle and then disconnect but instead of hooking up your amperage meter switch it over to volts --- If you see a consistent drop in voltage after the battery has been properly charged and it gets taken way down below 12.6 and continues to decline you know you have it ---
                            get a digi- meter with 00.00 increments --- It doesn't take all day,

                            You can time the last digit to your watch and after the battery is at 12.20 or .30 if the last digit still continues to drain down at a steady rate to the second you know you found plates that are either warped and shorting or conductive sediment at the bottom and or sulfated plates that are connected.

                            I just diagnosed a toyota last week with a battery draw, the alt. checked out as did the battery --- a quick check to see if the trunk light switch goes off when the trunk is closed checks out so I started pulling fuses and when I ran across the horn/emergency flasher fuse the draw went to an acceptable level (it was over 300ma) and went to under 80.

                            So I start checking the E. flashers -- good, i then go to the horn --- inop.
                            I go under the hood, their both disconnected, I plug one in and BLAAAAAT, I then go Ohhhhh - stuck relay - I go to relay and pull it and hear click --- I then go - Ohhhh - stuck horn button, I then pull it and its smashed to crap inside - the metal frame work is all bent up and shorting, I straighten it all out and put it together and perfect,
                            I then bring it up to the customer ( a little 110 pound female ) and ask her about her temper She said a deer leaped out in front of her in a subdivision and it was a knee jerk reaction, It was early and she was driving to work and she woke up the neighborhood ---- after a couple blocks she found where the horns were and disconnected them ( smart girl )
                            I explained to her that the horn and brake light system are independent from the ignition switch and work at all times so even though the horns were disconnected her horn relay was engaged at all times - she verified that she started having the battery drain shortly after the "incident".
                            I told her im a master at diagnoses and also told her I could tell by the angle of the bent framework that i would not want to get on the wrong side of her right hook,
                            she smiles and tells me im right again....


                            • #15
                              My Wife had one of those...
                              If I remember correctly, the clicking is normal, not to worry.
                              Installing fresh Battery will garbage the Computer Memory and most if not all the dash stuff, does not work!
                              The first time that happened I paid the Dealer to Reset the Computer.
                              After that, I found on the Web, the secret sequence of button presses to do a Reset.

                              Tom M.