QuestionQUESTION: My 98' chrysler t/c w/3.8 motor has 129000 miles. When I turn the key to on, I can hear several relays clicking and the service engine soon light clicks on and off. When I turn the key to start, the motor starts briefly and then dies. While the motor is running, it is spitting and sputtering and the tachometer is not registering. Any Ideas?
ANSWER: Hi Spencer,
Because of the multiple symptoms involving electrical systems and the quality of the running I would start with the battery and/or its connections. Check to make sure the clamps are thightly bolted to the posts (being careful when on the +post to not touch the wrench to anyother part of the vehicle so as to avoid a short). Then notice that there are three wires on the -post clamp. You will find that one goes to the near by frame rail on the inner fender and another goes to the rear of the engine. Check that the connections of those two wires are tight. Also consider whether the battery is nearing the end of its warranty as it may just be unable to provide the current/voltage necessary to run things (the multiple clicking of relays is a possible symptom of a discharged/compromised battery).
Finally, turn the ignition key: "on-off-on-off-on and leave on", doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage changes to show any 4-digit numbers beginning with a P. If so, let me know what those are as they may tell us more about the way the engine is running.
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi Roland, First of all, Thanks for the help. I changed the battery, no different. I tried the key on key off sequence several times,odometer just came back to the mileage. I traced negative wire to frame where there are two wires solidly connected with no corrosion. I could not trace neg wire to motor without cutting wireing harness. Where more specifically is this wire connected to motor? Also, when key is on position and relays are clicking, both fans come on and off.
Thanks, Spencer
ANSWER: Hi Spencer,
At least we know the battery is good. The engine ground is on the rear of the cylinder head (the driver's side end of the engine) but you found the main one with respect to this going on even when the engine isn't running so don't spend any effort on the other ground.
I suspect that something is shorting out the system when you have it in the run position which is dragging down the battery voltage, then the short having dropped the voltage far enough to cause the relays to open (whatever it is) releases a relay and the voltage recovers, only to be shorted again. Usually a fuse would blow in response to such a short. Because this happens when you just have the key in the 'run' position, before even trying the starter motor, let me go through the circuit and tell you the fuses to remove (one at a time) to try and see if by so-doing you can get it to stop doing this. It has to be a circuit that is powered up via the ignition switch.
Here are the possible fuses that are turned "on" by the ignition switch in the run position,
all are in the box that under the dash: fuse 2,6,8,9 which are in the row of fuses at the bottom of the box. Then there a fuse-like devices called Positive Temperature Coefficients and they are in the row that is just below the 4 large plugs of the box: PTC's 1,7,8,9. Try removing the fuses and the PTC's, one at a time, turn the key to run and observe for any change in behavior. If still the same, put the fuse back in and try the next one, etc. Let me know if anything is discovered.
Is there any other suspicious history about the inception of this behavior? Did you have a heavy rain or car wash just before this started, for example?
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi Roland, I tried all the fuses you suggested with no change.In the fuse/power box under the hood, the two relays that are clicking are, fuel pump relay and auto shutdown relay. I cant hear or feel any other relays clicking. I did replace the fuel pump relay when all this started happening on advise from others, no change. No rain or car wash preceeded problem. Car was fine when driven a short distance and died when put in park. It started back up and went a short distance again and then died again when put in park.
Thanks, Spencer
AnswerHi Spencer.
The ASD and fuel pump relay are supposed to click once when you turn the ignition to the run position (go on for a second then off), not cycle on/off repeatedly. To me this is due to the following possibilities:
PTC #1 is flaking on and off (check that with a voltmeter) due to a cracked wire (you should see one side of it has steady 12V, the other side the same, when you have the ignition switch in the run position. The ignition switch itself could be flakey in which case the pulsing would show on both ends of the PTC. Also, check fuse 23 in the power distribution center under hood which feeds voltage to the ignition switch to see if it has 12v steady across it when the ignition is off and also in run. If nothing seems out of order, then pull the asd relay and measure the voltage on pin 85 (the rear pin outboard) of the socket when the ignition is put in the run position. If that is pulsing (and all the fuses/ptc seemed steady) then I would suspect that the powertrain control module is failing. It should pulse once from 12 to 0 and back to 12V when the key is turned to run, and that is all.
Please let me know what you find.
Roland
