QuestionMy car keeps blowing the same fuse. It's the #10 fuse which says it operates LDP ABS, PTU SOL, ENG RLYS, and ENG MOD. What do i do to fix this so the problem will not continue?
AnswerHi Chad,
That sounds like a very important fuse. Unfortunately without the wiring diagrams I can't be too specific but can tell you a strategy for repairing this problem. First, the abbreviations means the following:
LDP (lead detection pump, part of the evaporative emission system, a pump connected to the charcoal canister via a vacuum hose),ABS (antilock break system, ignore if you don't have that feature), PTU SOL (part throttle unlock solenoid, which is the control for the torque converter that either unlocks or locks the two vanes of the unit for reasons of gas economy), ENG RLYS (engine relays, several important electrical control switches), ENG MOD (engine module, probably the actual control module for the engine).
This is an important fuse no doubt. You didn't say where it was located of its amperage rating. It very well could itself be sending power to several other fuses under the dash as I shall describe.
What you need is an ohmmeter to measure the resistance between the cold side of the fuse socket and ground (remove the fuse, turn on the ignition and with a voltmeter you will find the hot side of the socket (measures 12V to ground, which is any shiney metal surface attached to the body) and the cold side which will measure 0V to ground. Then turn off the ignition. Then measure the resistance between that cold side and ground (it will probably be near 0 ohms, which is why the fuse is blowing). What you then need to do is unplug each of the components or a fuse assigned to each component) that I listed above, one at a time, and see which one causes the resistance to jump from near 0 ohms to at least several ohms or better even more, but at least several ohms, which is the minimal value for the fuse to not blow when you plug it back in. I would suspect the LDP probably most, and the engine relays next, and the PTU SOL next, and the eng module last. It would be really helpful to have the wiring diagrams because there may be secondary fuses under the dash which power all these devices (that would surely be the case if the #10 fuse is in the engine compartment and was say a 30 or more amp fuse) in which case you could then remove the fuses under the dash for each of these devices, again one at a time, until you find the fuse that causes the resistance to rise on the cold side of #10. That then would be the device to trace further as to why it is showing such a low resistance (maybe a damaged component or an impaired insulator on a wire). At least then you could leave that fuse out and if it weren't critical would allow you to drive the car until you can get to the bottom of its problem.
So that is the approach, but I think you would be helped by having the real wiring diagram. Alldata.com sells such diagrams on line, but it may cost about $25. I don't know how complete the diagrams are in the Haynes manual for the Neon. The best diagrams are the Chrysler Corp shop manuals, but those will cover everything and cost about $75.
But see what you can do using my suggestions and then let me know what you determine.
Roland
