Complete Electrical Systems Failure

[Renaissance_Man]

Greetings to all.


I have a 2007 Dodge Caravan SE.


Following work done on the Right headlight, when I attempted to start the vehicle, the engine turned over normally for 2 - 3 seconds and then stopped. Additional attempts to start the vehicle were met with complete silence. Moreover, the entire electrical system was completely dead! No lights, no horn....absolutely nothing. The battery shows a 12 V + charge. As I am not familiar with all the electronic entanglements of newer vehicles, I referred to the shop manual for the Gen 4 Caravan, but found it to be of precious little help in pointing me towards a likely cause of this catastrophic systems failure.



A friend with some experience with automotive electronics suggested that I test the Automatic Shutoff Relay and the Main Relay. I was able to identify the ASR and when I tested it found approx. 75 ohms of resistance when 12 volts DC was applied across the switch leads. Since I had been told that I should have no resistance across the load leads, I thought that I had discovered the source of the problem, however replacement of the ASR with a brand-new one did not correct the problem. I have thus far been unable to find any reference to a "Main Relay". Does this go by a different name, perhaps?


Another friend of mine with many years of recent experience as a professional mechanic tried shorting the starter motor directly to the positive terminal of the battery using a circuit tester. While the circuit did complete, the starter motor did not turn over. This lead him to hypothesize that a) the ignition switch has failed or b) that the ECM has failed.


This brings me to my current situation as I work to get the funds together to replace the ignition switch. While I have no reason to doubt my second friend's professional abilities or opinion, while I work towards saving up to purchase a replacement ignition switch, I am wondering if there are any participants in this forum who might have additional insight into this perplexing, not to mention frustrating and rather expensive problem. Any help you can offer me in terms of troubleshooting this problem will be greatly appreciated!


I did have a look at similar issues as suggested by the forum software, however of the posts suggested, none of them matched up with the symptoms I have experienced. If I missed something obvious, please forgive me.

[Stealthee]

You should be able to short the starter relay to get it to turn over. If it still doesn't turn over then you can eliminate the starter as a possibility.

[Renaissance_Man]

Thank you for sharing your insight. Believe me when I say that I am only too happy to consider any reasonable suggestions and insights that someone may have.


Shorting the starter relay is what I believe my friend with the experience as a professional mechanic tried. Since the didn't accomplish anything at least now I can rule out the starter motor as the cause of this issue.


Acting on the advice of yet another friend who is a graduate EE, I undid the changes I had made to the right headlight as well as looking the associated wiring over for any indication that I could have inadvertently removed some insulation, but I could find no evidence to support that possibility. I connected the van to a fully charged battery pack and tried to star it, but this time, there were no clicks, whirring sounds or any evidence of life - EXCEPT I did observe that both of the turn signal indicators in the instrument cluster flickering rapidly. This flickering continued even after switching the ignition off. At that point, I disconnected the battery's ground lead. That gives me yet another lead to research. I love a challenge, there can be no doubt, but this is beginning to border on the absurd!


Hrmmm....I wonder if I can find an Amish person, that would swap me even-up for a horse and buggy?