McGregor93XJ

Hey Jeepers!

My XJ died in flight this morning on my way to work. I've now got a crank but no start. In the engine compartment fuse block, I found the 30amp "engine control 1" maxi fuse blown. What circuit does that fuse protect? Alternator? Ignition coil?
I have a chilton manual & it does not list this fuse or say what it covers. Either I'm too stupid to find it on the wiring diagram or it is well hidden.

Please advise!

Thanks.

cherokeeguy

I'm going to try and help you out. What's the fuse number? Your refering to the Power Distribution Center under the hood, correct?

5-90

If you have MAXI fuses for the alternator, they'll be a pair of MAXI60 fuses labelled "Generator."

"Engine Control I" sounds like it would apply to the PCM and/or a batch of engine control drivers - ignition control, fuel injector drivers, sensor source/reference signals, and like that.

Do you honestly mean to tell me, however, that you don't have a box of spare fuses in your truck? For shame! Go get yourself a plastic compartmented box, and put in it:
- At least one of every rating/type of fuse you have (probably just MAXI and ATO/ATC in various ratings)
- At least one of each type of relay (definitely DIN, probably mini-DIN. You can get them pretty much anywhere)
- At least one of every type of bulb used on the exterior, save (possibly) headlamp capsules (if you've converted) or sealed beam headlamps (which won't fit anyhow.)
- A small handful of interior bulbs (IP and controls probably take #168/#194s, with auxiliary illumination taking #37/#74s)

Throw necessary small tools in your glove box (for me, it's #2 Philips turnscrew and a 10m/m nutdriver.)

Someone tells me I've got a lamp out; I'll pull over, fix it, and be on my way in less than five minutes!

McGregor93XJ

correct- it is the green 30a fuse, 2nd one down from the top. I replaced it, and as soon as I switched the key on it popped again. I cant seem to find what circuit this is protecting...

waoracing

I'm going through the same problem with the same fuse on a 92 xj with 4.0. I've read other post on this forum and keep coming up with no answer. Have you had any luck? I did find that when I disconnected the "60 pin" connector going to the ECM which is located next to the air filter box on the driver side and tried to start the fuse did not blow. This leads me to believe that the ECM is bad but with so many sensors behind it I am hesitant to replace it.

Willys55

Fuel pump, injectors, ignition coil, generator field(alternator),oxygen sensors.

Before you try another fuse, unplug the 02 sensor(s), fuel pump relay,and fuse #14 ecu. Put a new fuse in , or a 30amp circuit beaker(for testing purposes only) then plug in the 02 sensors.....if the fuse stays good plug in the ecu #14 20amp fuse. If the fuse is still good plug in the fuel pump relay...if fuse pops then your pump is shorted or the wiring is shorted to ground

mud'njeep

i know this is a old thread but i'm having the same problem any luck on whats going on? i didn't test it yet i just know its popping the fuse as soon as i turn the keep on.

ms52390

A good way to test is to put a multimeter on the fuse pins with the key off and do a continuity test. If you get a beep with the key off then you have a short somewhere, if no beep then have someone turn the key on and see if your meter beeps then, if it does then it would have blown another fuse. I would check your other fuses and relays in the PDU for blown connections. Also, check the fuse panel under the drivers side of the dash.

freegdr

Check o2 wiring for contact to metal on newer xj they fall on ds and wear thru.

McGregor93XJ

Check your exhaust!!! Mine had a o2 sensor wire touching the manifold causing the short to ground. I repaired the wire & moved it out of the way with a zip tie. This fixed it. Hope this helps.

mud'njeep

Thanks for all the info i'll have to check everything and see what i can find.