Broke down - Ignition Coil not getting power

levergun · Apr 14, 2008

Unscathed said:
What is the PDC?

Power Distribution Center- fuse box

Unscathed · Apr 14, 2008

levergun said:
Hi.
First thing the pickup in the distributor is the cam sensor.
Now. You said there is no power to the coil??? And no CEL.
The computer controls the ground side of the world. It grounds the coil to makes the spark. The coil + is always hot when the IGN is on. If there is no power to the coil with the IGN on and no power to the PCM (hence no CEL) I would guess there is a power feed problem. Possibly the ignition switch. I would check the power coming in and out of the ign. switch and check to see if the PCM has power. Also, does the fuel pump kick in when you turn the key??? If not I would seriously suspect the ign switch.

Ok.. I went into Napa and asked for the cam sensor.. they looked it up and said there wasn't one.. but then they offered me the pickup under the cap.. Which is the cam sensor as you are telling me.. lol..

Unscathed · Apr 14, 2008

I got it working... Holy cr@p....

IT WAS the damn DOME LIGHT fuse.. it didn't look like it was blown and I must have skipped over it by accident!!

How retarted...

I mean.... what if I didn't want my dome light on?.... lol..

So I spent
$61 crank sensor
$32 coil
$38 cam sensor
$20 tow rope
and it was a 2 dollar fuse that didn't look blown.

139588 · Apr 14, 2008

check your crankshaft sensor. same exact thing happened to me and my crankshaft sensor was broken.

Unscathed · Apr 15, 2008

LOL.. I replaced that already...

It was the damn DOME light fuse.. talk about piss you off..

pat8942 · Apr 15, 2008

You might want to invest in a test light it's handy for checking fuses.
If you don't want a dome light just unplug the door switches.
Not to be a wennie but you should never buy things until you do the proper diagnostics and are sure that's what you need.
On the bright side you have some spare parts.

Unscathed said:
I got it working... Holy cr@p....

IT WAS the damn DOME LIGHT fuse.. it didn't look like it was blown and I must have skipped over it by accident!!

How retarted...

I mean.... what if I didn't want my dome light on?.... lol..

So I spent
$61 crank sensor
$32 coil
$38 cam sensor
$20 tow rope
and it was a 2 dollar fuse that didn't look blown.

Unscathed · Apr 15, 2008

Well it was better then towing it to a stealership 100+ bucks, then another 140 for them to diagnose the problem.. and like they would have told me it was a blown fuse.... Riiiiiiiight.. they would milk me for everything..

I just look at it as a much needed Additional Tune up.

I was joking about the dome light bit... I haven't had the bulb in it in like forever.. it burned out.

I did have my voltage meter which beeps when testing continuity, but I left it at work yesterday and started working the problem yesterday... between nightfall yesterday, and working in the COLD rain today out in the middle of a parking lot.. you just don't really think with your head totally on straight.. lol.

lesson learned.. but I learned it before buying a rebuit ECC.. lol!!!

These parts were all original anyway.. guess it was time for an ignition overhaul anyway..

laybackman · Apr 15, 2008

One question. Does this YJ have an alarm? If so that is why the Jeep probably died. The alarm uses the dome light circuit to arm itself and could possibly shut down your Jeep if it is not getting power to the dome light circuit.

Unscathed · Apr 15, 2008

Nope.. no alarm.. never did.. Keep in mind.. it blew the Dome Fuse..

So there may still be a problem.. but I know where to start

pat8942 · Apr 15, 2008

I suggested the test light so you could keep it in the Jeep.

Unscathed said:
Nope.. no alarm.. never did.. Keep in mind.. it blew the Dome Fuse..

So there may still be a problem.. but I know where to start

laybackman · Apr 15, 2008

Unscathed said:
Nope.. no alarm.. never did.. Keep in mind.. it blew the Dome Fuse..

So there may still be a problem.. but I know where to start

Took a look at me FSM for my '95YJ. It appears that the dome light, courtesy lights, and light under the hood hood get their power through a 10A fuse in the PDC under the hood and not through the ignition. That's why they work even if the ignition switch is in the OFF position. The ignition switch also gets power for the start circuit from a 40A fuse in the PDC for the starter. BUT the ignition also gets power through a 15A fuse in the fuse lanel for the 'fused ignition switch output' (run/start) cycle connected to pin 1 of the ECM. Did the 15A fuse I just mentioned blow? If not then you may have a short of some sort.

pat8942 · Apr 15, 2008

I did the same thing and I didn't see any relation between the dome fuse in the PDC with anything that would cause the coil not to get power.
It does seem strange.
Maybe we just think too much.

laybackman said:
Took a look at me FSM for my '95YJ. It appears that the dome light, courtesy lights, and light under the hood hood get their power through a 10A fuse in the PDC under the hood and not through the ignition. That's why they work even if the ignition switch is in the OFF position. The ignition switch also gets power for the start circuit from a 40A fuse in the PDC for the starter. BUT the ignition also gets power through a 15A fuse in the fuse lanel for the 'fused ignition switch output' (run/start) cycle connected to pin 1 of the ECM. Did the 15A fuse I just mentioned blow? If not then you may have a short of some sort.

xeroid81 · Apr 16, 2008

levergun makes a good point. i've been plagued at one time w/ a similar ignition prob. in my dakota where i scratched my head for weeks. it was a 12v feed from the dist. box to the ign. mod. it has to be a good 12v. anything less will cause that same prob. i cleaned the whole engine compartment w/ some goop prod. and the wet wires led me thru about10 ft of harness before i found the 12v. feed shorting to another wire bringing it down to only 3v. sounds like you have a similar prob. get a voltmeter and haynes or chilton manual and check that circuit out. it's worth a look. good luck with that one.

Unscathed · Apr 16, 2008

laybackman said:
Took a look at me FSM for my '95YJ. It appears that the dome light, courtesy lights, and light under the hood hood get their power through a 10A fuse in the PDC under the hood and not through the ignition. That's why they work even if the ignition switch is in the OFF position. The ignition switch also gets power for the start circuit from a 40A fuse in the PDC for the starter. BUT the ignition also gets power through a 15A fuse in the fuse lanel for the 'fused ignition switch output' (run/start) cycle connected to pin 1 of the ECM. Did the 15A fuse I just mentioned blow? If not then you may have a short of some sort.

Yea.. the 15 amp fuse in the cab blew.

laybackman · Apr 16, 2008

Unscathed said:
Yea.. the 15 amp fuse in the cab blew.

I happend to be going over that particular circuit again and noticed that the fuse for the ignition I mentioned earlier and the fuse for the dome lights have a commonality. The ASD relay is tied to fuse #9 - 15A, which also is tied to the domes etc. and fuse #5 -15A for the ignition run start circuit which I believe you blew. This fuse ids inb the middle of the fuse panel. Fuse #9 would be in the next row over and down one fuse. Sowhich one did you actually blow?

If the fuse (#5) for the ignition circuit was the only fuse affected, the short if any would be in the wire from the ignition switch back to the fuse or the ignition switch itself I would think.

Broke down - Ignition Coil not getting power

levergun

Unscathed

Unscathed

139588

Unscathed

pat8942

Unscathed

laybackman

Unscathed

pat8942

laybackman

pat8942

xeroid81

Unscathed

laybackman

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