Not starting no power to coil or fuel pump
So power is going to the fuse box under the hood. And the jeep cranks but no spark to coil. Fuel rail had no pressure until the pump was jumped to see if it works which it does and is pressurized now.
Ignition switch????
Wiring problem?
The jeep has been sitting over the winter and started before then.
Also the passenger side fuse box has NO POWER at all
Please help thank you
Ignition switch????
Wiring problem?
The jeep has been sitting over the winter and started before then.
Also the passenger side fuse box has NO POWER at all
Please help thank you
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
So power is going to the fuse box under the hood. And the jeep cranks but no spark to coil. Fuel rail had no pressure until the pump was jumped to see if it works which it does and is pressurized now.
Ignition switch????
Wiring problem?
The jeep has been sitting over the winter and started before then.
Also the passenger side fuse box has NO POWER at all
Please help thank you
Ignition switch????
Wiring problem?
The jeep has been sitting over the winter and started before then.
Also the passenger side fuse box has NO POWER at all
Please help thank you
What year XJ?
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
Check some fuses in the PDC.
Below is a pic of the PDC for a '99 but is similar to the '98. Below that is the layout of the PDC that I have annotated the maxi fuses.

Below is a pic of the PDC for a '99 but is similar to the '98. Below that is the layout of the PDC that I have annotated the maxi fuses.

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CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
There's a possibility that your CPS is causing the no start and instruments inop.
Unplug the CPS connector, turn the ignition switch to RUN, see if the gauges come back. If they do, it could be a defective CPS causing both problems.
If you decide to change the CPS I recommend using an Mopar CPS from the dealer. Aftermarket CPS' have a habit of failing right out of the box, or very soon while in service.
Unplug the CPS connector, turn the ignition switch to RUN, see if the gauges come back. If they do, it could be a defective CPS causing both problems.
If you decide to change the CPS I recommend using an Mopar CPS from the dealer. Aftermarket CPS' have a habit of failing right out of the box, or very soon while in service.
There's a possibility that your CPS is causing the no start and instruments inop. Unplug the CPS connector, turn the ignition switch to RUN, see if the gauges come back. If they do, it could be a defective CPS causing both problems. If you decide to change the CPS I recommend using an Mopar CPS from the dealer. Aftermarket CPS' have a habit of failing right out of the box, or very soon while in service.
The fuses that you told me to check for the fuel and ignition we're good too
I checked the one photo and found out that the fuse box under the hood the fuse for for fuel and ignition doesn't get power
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
Unplugging the CPS didn't do anything I check the fuses that didn't do anything to the gauges
The fuses that you told me to check for the fuel and ignition we're good too
I checked the one photo and found out that the fuse box under the hood the fuse for for fuel and ignition doesn't get power
The fuses that you told me to check for the fuel and ignition we're good too
I checked the one photo and found out that the fuse box under the hood the fuse for for fuel and ignition doesn't get power
I don't see a fuse marked "Fuel and Ignition".
What fuse number is it - F20?
CF Veteran
Joined: Aug 2010
Posts: 8,357
Likes: 103
From: Canton, MI
Year: 1999
Model: Cherokee
Engine: 4.0
Here's some wiring diagrams for the ASD circuit.
Check F18 in the PDC and recheck F11 in the JB.
For F20 and F23 you need the ignition switch to RUN/START (Engine Cranking). The PCM provides a ground to the control coil of the ASD relay when it sees an engine rotation signal from the CPS. If the PCM does not see this CPS signal, it won't pull in the ASD relay, thus no power to the coil, fuel injectors, or O2S heaters. Also, the fuel pump won't operate when cranking, as it should.


Check F18 in the PDC and recheck F11 in the JB.
For F20 and F23 you need the ignition switch to RUN/START (Engine Cranking). The PCM provides a ground to the control coil of the ASD relay when it sees an engine rotation signal from the CPS. If the PCM does not see this CPS signal, it won't pull in the ASD relay, thus no power to the coil, fuel injectors, or O2S heaters. Also, the fuel pump won't operate when cranking, as it should.


Last edited by CCKen; May 19, 2015 at 07:44 AM.



