waldojeffers

98 Cherokee 4.0
Changed plugs, blew 15A fuse...limped home through 2 more, then reset computer, changed air filter. Started fine, ran much better, then blew another fuse after hitting operating temp.

Most sensors & emmission parts were replaced a year ago...other than wires, I'm out of parts to replace.

Ideas ?

OverlandZJ

Which fuse is blowing?

waldojeffers

The Box does not identify what is on the circuit, but when it's fried there is no spark. I think it covers the entire emission system. It is 2nd from the left on the bottom row of fuses between the huge relays (top) and the 30-50A Fuses. Book does not have a schematic and I do not have a real manual.

Help appreciated.

OverlandZJ

This is the power distribution box underhood?

waldojeffers

Yes. The smaller fuses in the middle are not identified.

Pit1981

I think this is your fuse panel. I think

http://www.fixya.com/uploads/Images/068E60A.gif

fantic238

if there is a number or a letter check in the users guide under "fuses".

waldojeffers

Not sure if it's the correct year, but it appears to be the interior panel, not the box under the hood.

In there, there are 4 large relays (Fuel pump, Starter, ASD, Fan) Top >
Then space for 4 smaller relays (ABS, 2 Fog, A/C Clutch) >
Then 11 spaces for 10-20A small "blade" fuses, the bottom left center of this group is what keeps blowing. >
Then 2 rows of larger 20-50A (blower, cooling fan, starter etc)

Manual lists what is in the interior panel, cover under hood specifies what everything is EXCEPT these 11 fuses in the middle.

The fuse that keeps blowing has to control emissions and coil....once it blows, car immediately dies.

duncan0668

The 2nd fuse from the left on bottom row is F22 for the A61 circuit, that is the fuel pump relay in the PDC. this is from a 1999 factory service manual.

waldojeffers

Not sure if there is a difference vs 98, but the fuse that keeps blowing is not the fuel pump based on lack of spark (when blown) and how it dies under power when it blows. Also, there is a large Fuel pump relay identified under the cover. Here is what the cover looks like, fuse in question is above the latch (2nd down on left with picture off 90 degrees).

waldojeffers

After getting to a mechanic without Jeep but with cover - Duncan is correct - it IS the fuse for the fuel pump circuit ?!? I switched the large relays around to make sure that isn't the problem and that is OK.

Ideas on what is causing the problem ? Perhaps unrelated to the plug replacement ? More confused now than when I first posted.

Thanks in advance.