Dale Reed wrote:
Ok, I replaced the battery with a X2 AGM battery, 880 CCA's. I also found a blown fuse under the hood. The blown fuse was #16 (ASD Feed). I replaced the fuse and cleared the codes. Vehicle started and ran for about 1 block. The ASD Feed fuse (15A) keeps blowing.
What causes this fuse to blow? What is the ASD? Thank you in advance.
This fuse does not actually feed the ASD relay but rather passes power to various components listed below when the ASD Relay energizes...
This fuse 16 feeds the Front Control Module....which is why the engine dies when the fuse blows....it is possible there is a fault with the Front Control Module but this fuse also supplies power to the air-con clutch relay coil, cabin heater relay coil, low speed fan relay coil and high speed fan relay coil. These relays are all mounted on the PDC where they get their feed from fuse #16 so I doubt there is a short there but it is worth pulling these relays out in case one of them has a shorted coil.
What is more likely to be blowing the fuse is where the wire from the fuse, a Brown/Pink wire, leaves the PDC it is picking up a short.
When this wire leaves the PDC it goes to the Front Control Module below the PDC on the left front fender, to the EGR solenoid, the EGR Flow Control Solenoid, the ECM, the Vacuum Reservoir Solenoid, the Boost Pressure Solenoid and finally the Glow Plug Module.
The circuitry is shown on pages 8w-10-19 and 8w-10-20 of the 2005 KJ Service Manual circuit diagram which you can download here:
http://www.colorado4wheel.com/manuals/Jeep/KJYou will need a Digital Multimeter to check this Brown/Pink wires' continuity to chassis......disconnect the battery first....assuming there is a short or virtual short then pull out all of the connectors to the above listed components to see if the short suddenly dissapears. Disconnecting connector C105/C114 as shown on 8w-10-20 will isolate some of the components and some of the wire run...the circuit diagrams will show you the location of the various connectors.
If you are very unlucky, you may find that even after pulling the connectors to all of the components listed and removing the relays listed you still get a continuity reading on this Brown/Pink wire to chassis then it means that this wire is being pinched somewhere down to chassis or to some other random wire.....I have been there, done that and got the T Shirt about 6 times with the wiring on my 2005 Export CRD after the harness got damaged somewhere up front after a front collision with a tree. I do not know about the LHD models but on my RHD KJ the wire harness does not take the shortest route point-to-point but runs around the complete engine bay like the Washington DC Beltway!
Edit to add:
The fact that you could drive for about a block before the fuse blew again would tend to indicate that there is not a firm short to chassis of this Brown/Pink wire but rather as one of the solenoids on the circuit gets energized then too much current gets drawn, unless there is only a wire shorting when you go over a bump or something. When you are testing the resistance of the complete circuit as above you may be lucky that you will pick up that one of the solenoids has an internal short to chassis...pulling the connector off that solenoid will enable you to measure the resistance from its male pins to chassis....there should show complete open circuit to chassis while between the two pins there should not be less than about 2 Ohms; 2 Ohms would mean that that solenoid by itself will draw about 6 amps already, 1 Ohm would be 12 amps or almost the rating of the fuse.
You could try driving with some of the solenoids disconnected....should get a CEL but hopefully you could drive for a while without the fuse blowing. The negative side of all these solenoids/relays gets its ground from the ECM/Front Control Module when running....usualy this ground is in a pulsed form (Pulse Width Modulation) to vary the power of the solenoid. You can test the solenoids by
briefly applying voltage directly across the exposed, disconnected male pins which is best done by using the Multimeter in "Fused 10 Amp" mode in series with the + side of the battery and the positive pin of the solenoid and add a temporary ground to the ground pin of the solenoid. This will show you how many amps the solenoid is drawing...more than 10 amps will blow the fuse in your meter which to me would indicate a bad solenoid!
So download this 2005 KJ Service Manual and have a look at the circuitry and with the correct logic pages in front of you I can try help you with any further questions.