i only wish i knew, the truck ran great until a few weeks ago. out of the blue it just shut off while driving, if you look at the earlier post i have changed just about everything i thought to be the culprit. i have NO codes and NO check engine light. the truck fires up like new runs like new for 10 minutes at a time....got gas got spark over 12V out of alternator and shut off over 12V at battery. if it was bad plugs or spark i'd run like crap from the get but not the case. there are only 3 more sensors i see on this 3.7 and 1 is temp gage, one twist in sensor in the intake drivers side front and one on the front of intake behind temp sensor which the pigtail is really latched on i can seem to unplug. dodge really didn't want there pigtails coming off....

 

Evap Canister/Charcoal Canister


SJ03

 

does the 3.7 have an EGR? i can't find it but scanning the web doesn't look like it does.

 

new update 5/5 after testing endless wires with a multimeter all were good.....after cleaning and checking some pigtails started the truck one last time and the dash went blank, tried a few more times and it's like there is no battery in it. battery tests out to almost 13V. i can only hear a very, very faint dash dinger. i think the computer is toast. front what i can see the visual fuses none are blown. once in every few turns of key i hear a slight tick from starter but nothing else on the dash. can i test a computer for power with a multimeter?

 

If something like that goes it should be all or nothing. The fact that there are some signs of life may mean you have a bad engine ground or a loose connection to your TIPM (Fuse Box). I would do some voltage drop tests. Other than that, instrument cluster, PCM, ignition switch, wiring, start simple.

 

I would have to guess the front control module--fcm and/or (both) power distribution module--pdc--, 2003 does not have a tipm, totally integrated power module, that started in 2006. If you have an obd II scanner , link to the ecm, chances are, the ecm is ok. Most of the chasis power and lighting signals come from the fcm, like head lights/tail lights turn signal. I'm not sure, but I believe the power up for the instrument cluster comes out of the fcm/pdc also.


Best thing to get is the factory service manual that has the wiring diagrams and some diagnostic ladders as well