Chrysler Repair/97 Chrysler LHS 3.5: no start
QUESTION: I made a big mistake. My 97 Chrysler 3.5 would start and run but ran like crap and then the 20 amp fuse for engine controlr. would blow.This happened like 3 times so I stuck in a bigger fuse. The fuse didn't blow but the car would no longer fire. So I melted something. Upon future investigation I realized the ignition coil pack was cracked and melted so I replaced it. Put in a 20 amp fuse again and tried to start car. Fuse is holding fine but car will not fire. What do you suggest I replace next... Thanks
ANSWER: Try turning the ignition switch on-off-on-off-on and leave on, doing that in 5 seconds or less elapsed time. Then watch the check engine light which remains on to see it begin to flash, pause, flash. Count the number of flashes before each pause. Then repeat to be sure of an accurate set of counts and let me know what they are. Also, tell me the number/letter of the 20 amp fuse that kept blowing.
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QUESTION: I don't have any fault codes. I'm sending a picture of the fuse box, my finger is pointing to fuse that was blowing. It is the Engine Contlr fuse. Roland, I guess my question to you is, What controls the Ignition coil pack, what tells it when to fire.
The PCM or the ECM... I think that fuse supply's power to fuel pump ignition coil and injectors. I think something after the fuse opened like a fuse link or something. I will do anything you suggest, I'm to far into this car to give up now.And Thanks
ANSWER: Hi William,
That is fuse B and it powers: the transmission control module, the powertrain control module, and the automatic shutdown relay (which in turn powers the fuel injectors, the spark coils WHEN cranking and running the engine).
What do you mean "don't have any fault codes"? Does the check engine light flash at all, or even light up?
Do you have 12v showing on both sides of fuse B?
Do you hear the fuel pump run for a moment when you turn the key to the "run" position?
Do you have spark when you crank over the engine?
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QUESTION: Hi Roland, please don't give up on me. Turning the ignition switch on-off-on-off-on and leave on. The check engine light comes on every time and when it comes to the point leave key on it stays on for about two seconds & goes out. I have power on both sides of the fuse as in the photo. I can hear the fuel pump working and I can smell some gas cranking. I have NO Spark. The Auto shut down relay is working. I have a new ignition coil pack installed. If I would of just changed the coil pack to start with the car would be running, but stupid me put in to big of a fuse and melted something... OMG... Thanks Ralph
Anyone reading this if you like to help, my e mail is
Do the ignition switch on-off-on-off-on and leave on one more time, only then look at the odometer window of the cluster to see if the mileage disappears and in its place there is a 4-digit number preceded by a P. This '97 year was the change from obd-I to obd-II codes and so it may be as I described it, one way or the other. If it were the former you should have at least gotten two sets of 5 flasheds each (means 'end of code readout'), so look at the odometer this time.
Given the history of the spark coil melting, I wonder whether the 12v wire that powers the spark coils comeing from the autoshutdown relay to the spark coil might have burned out. That wire runs from the rear-most pin of the ASD relay socket to the spark coil plug and is dark green/orange in color. So either check for continuity of that wire, or measure for 12v to present on that wire's pin at the spark coil plug while you are cranking over the engine (and thus the ASD is "closed". The dark green/orange wire's pin is one of the two pins on the other side from the locking tab of the plug). If that checks out:
The spark coils also needs there to be a cam and crank sensor that is working to "drive" the coils via the pcm. So you could check those sensors out with a voltmeter. With the key in the run position, there should be 8V on the orange wires at both those sensors, and then read the voltage between the other 2 wires at each plug (probe through the insulation of the wires with fine pins to make contact) and then while you turn the crankshaft by hand with a wrench on crank pulley bolt you should observe the voltage to oscillate between 5 and 0.3v several times per revolution. There are fault codes for those sensors, but we may not be able to get the codes...