Randy Lawson

I have a 2004 Grand Cherokee Overland Edition, 4.7L
I am not a certified mechanic, but can handle most personal vehicle problems.

So here is the issue.. I have No cluster lights, No Power to Obd Connector, No Head lights..

I have checked all fuses under hood and inside visually and with ohm meter, I have probed the Obd connector with test light and a multi meter and got nothing out of either, Also checked the pins in the connector. I have power to cig lighter, I have checked grounds on the firewall, next to fuse box under hood, and on the engine block. All grounds that i have found i took off and cleaned and all seem to be ok..

I'm just completely stumped on where to go from here, Im missing something just cant find it..

I need to be able to use a scanner tool to relearn for the crank sensor i recently replaced, but cannot do so without power to the connector inside the jeep..

BlueRidgeMark

Welcome, Randy.

How about some history? Were you working on the Jeep? Did this just happen all by itself? Did you go through a car wash with the sunroof open?

How about other electrical? Will it start? Headlights? Turn signals? Brakes? Dilithium frambulator bank?

Noah911

Is the rest of the cluster working fine, or is it just that you have no lights iluminating like they should be on the cluster? I guess what I mean to ask is are the instruments still working okay (gas gauge, rpm, speedometer, etc...)?

I do not know that it is.. as it does not exactly sound like it is to me? Even so, it is such an easy test to start out with doing anyway. Have you thought about testing to see if you have a healthy working PCI (DATA BUS)?

A healthy PCI DATA BUS on a WJ will have a fluctuating VOLTAGE of 2- 2.5 VOLTS on it, measured at the Data Link Connector (DLC- OBDII port), on the #2 pin, with the ignition key on and/or when the engine is running.

Maybe you could verify the data BUS real quick. If it shows ZERO (0) VOLTS, then the PCI BUS line has a short in it somewhere. If it is regularly fluctuating at greater than 2.5 VOLTS (closer to 7 VOLTS), then the PCI data line has a faulty component on it somewhere that is pulling the bus power.

Even though it may not appear exactly like it is a data BUS problem.. Still, ruling out a BUS problem for in your situation sounds to me like it is a very important thing to get done, or else you may never be able to find the problem if that is what it is...

A fault in the data BUS line can be the cause for all of those issues combined.

Noah911

I read it again what you said. You have no power to the OBDII port any at all? It does not power up the scanner? Is that what is happening?


Is it the #16 pin you have tested for power with a multimeter, and it has no 12 VOLTS? Did you check it both ways.. between the ground pin, as well as between an actual chassis ground too?

Did you go back further behind the DLC to pierce and test the wiring for the #16 pin to trace it back there for power as well?

It sounds like you are sure of all the fuses being okay? I would say double check the fuse(s) twice more, since you have no headlights, and swap in a spare fuse to be sure. Clean the contacts of the terminals and the fuse...

Do you have an amp for the radio? I have heard of a radio amp causing something like this to happen. If you do, try disconnecting it to see what happens?

Randy Lawson

Update, today im going to clean up the grounds and hook them back. Iv done this to about every ground i can find.. after that i will test dlc again, if i still get noyhing im im go try to follow dlc wires back further for more probing.. if i cant find anything else wrong, is there a relay that would be causeing this problem?