I have 2003 Dodge Caravan SE 2.4L. I had not driven it for about 3 weeks, because we recently bought another used vehicle. One day my wife went in the garage and the minivan was making a constant noise, but it went away. I tried to start the car, but the battery was completely dead. I grabbed my portable jump start device and the car was cranking and all of the sudden it did like of it did not have enough power. I decided to do it the old fashion way with jumper cables and this time the fuel pump would not come on. I then checked the fuses and the fuel pump fuse was blown. When I went to replace it with a new one..... it blew it immediately. I Google and someone said to remove the fuel pump relay to remove the Pump from the equation. If the fuse did not blow then it was a bad fuel pump, but if the fuse blew it was not the fuel pump. I did that and the fuel pump fuse still blew with the fuel pump relay disconnected.

I decided to take the battery to Walmart to have it tested and it was a bad battery and got it replaced under warranty. I am trying to see whats going on and if jump starting the car with a bad battery could had damaged the PCM? I really hope is not the fuel pump....., because last time I changed it, it was a pain. I rather it be the PCM, since it would be cheaper to send it out to people on eBay who can repair it for $90.
I really doubt it is a grounding issue, since it was cranking at the beginning. Any advice would be greatly appreciated..... Could the PCM be blowing the fuse? I mean it blows immediately as I connect the negative cable back to the battery.

 

Update:

Disconnected the PCM completely, put a new 20AMP fuel pump fuse, and removed the fuel pump relay and put a pin connecting 87 & 30 to send power to the fuel pump and the fuel pump motor is working. I am leaning towards the PCM and not a grounding wire. Can anyone confirm this for me?

 

So the fuse blew as soon as you installed it, without turning the key on?

The fuel pump fuse also provides battery power to the PCM, and there could be an internal short, but having been parked for 3 weeks, mice could’ve nested in the engine bay somewhere and damaged the wiring harness. I’d recommend a thorough inspection of the harness before attempting any repairs or replacement of the PCM.

What was the noise it was making? A groaning/whirring/humming type noise or a clicking?

 

Thanks for replying back. The fuse blows as soon as I put it in without the key in the ignition. So basically it cannot be the fuel pump since it doesn't come on until the key is on the on position. I did disconnect the pcm and the fuse doesn't blow and I bypass the relay and the fuel motor comes on and the fuse doesn't blow. The car was inside the garage where no critters could get to it. I'll upload a video my son took to youtube, because I wasn't home when it happened. I was laughing when I saw the video, because it looked like someone was playing music..... It has a rythym.

https://youtu.be/Ol5wJf5hHSM

Now my wife and son tell me the sound was coming from the driver side front tire the exact location where the computer is hidden in. Let me know if you also think it's the PCM. Thank you.

 

The noise sounds like an actuator or solenoid that’s trying to engage/disengage and can’t - this is a common problem when the battery is too weak to supply adequate power. The only device that should be functional with the key off is the leak detector for the EVAP system and that is also mounted in that same area (lower left side of the engine bay).

A weak/dying battery can cause some pretty strange things to occur because the control modules are trying to maintain their normal functions and can’t due to the lack of power, so I would consider the noise a symptom of the battery needing replacement (or possibly a cause of the battery dying, but that would be something to test after you determine the cause of the fuse blowing).

The circuit that feeds the PCM from the FP fuse is an Orange/red wire in cavity 29 of connector 1 at the PCM. I’d recommend using a test light (grounded to battery negative) as a load at the connector - if the fuse blows, it’s a short in the wiring. If not, the PCM is in need of repair or replacement.

As for critters not being able to get to your van - don’t kid yourself about how easily they can intrude into a garage, regardless of how well it may be sealed. Mice in particular can squeeze through cracks as small as 1/8” and can be quite crafty in where they build nests. I’ve found them in almost every conceivable location in the engine bay, under the windshield cowl, on top of HVAC housings or on top of the cabin air filters and other places where the owners never suspected mice at all.

Oftentimes there’s no clue until you start taking things apart, so get a good flashlight and take the time to remove a few things like the engine cover or fender liner to be sure. An inspection mirror would help as well.

 

Meant to include this - here’s a view of the PCM connectors.

 

Different scenarios I tried:

1. Everything connected without the PCM and I connect the negative to the battery the FP fuse doesn't blow.
2. As soon as I connect the PCM and connect the negative to the battery the FP fuse blows.
3. I tried connecting all the PCM connections except the one labeled C1 that has connection to the FP fuse and the fuse doesn't blow.

Someone told me that it could be the IPM, which has had many problems with many Chrysler/Dodge vehicles. TIPM gets moisture and dirt in and causes corrosion. I did remove the TIPM, didn't see much corrosion, but there was a some sand on the TIPM. I was going to blow air to remove the dust and sand and spray it with alcohol. But, If it was the IPM...I would assume the fuse would blow without the PCM connected. Seeing that it only blows when the C1 PCM plug gets connected..... leads me to believe the PCM is BAD or the Orange Red wire coming from the PCM to the FP fuse is making ground somewhere else. But OR/RD wire is neatly bundled and I didn't see any rips or tears where the wire would be making ground. Also if that wire was making ground, even after disconnecting it from the PCM it would still blow and it doesn't... it only blows as soon as I connect the C1 to the PCM.

I tried what you said and to connect a test light to the negative of the battery and put the prong in the OR/RD wire on the C1 plug. Since the test light end was large, I inserted a small paperclip to make contact with the OR/RD wire and used a gator clip wire to connect the paperclip to the test light end. Then, I proceeded to connected the negative wire to the battery and the Fuel Pump fuse still blew. I am not sure if the IPM is the problems,since it doesn't blow the fuse without the PCM connected. I don't think is a frayed wire, since it would have blown without the PCM connected.... If the wired is grounding between the PCM and the IPM. I added the diagrams to see if you can give me more advice. Thank you.

 

I decided to cut the OR/RD wire higher up to have room to fix it later from the C1 plug to make sure it wasn't any other wire on the C1 grounding. I had a good fuse in the FP and connected the C1 connector back on. I then proceeded to connect the negative cable to the battery and the FP fuse did not blow. I tested the OR/RD wire for ground with the test light and it wasn't grounded. Without that wire, the car is still totally dead where it won't crank or the fuel pump will not come on. I don't think that wire would keep the car from starting or cranking... would it? I think the computer is fried. I think I am to the point where I think I am 99% sure the PCM is the problem. What do you think? IPM looked good and connections were good too. The Minivan has been kept inside the garage where it is not exposed to constant outdoor weather to cause the IPM to corrode. Inspected IPM and connections looked good and it was in better shape than the ones I seen on YouTube videos that have much corrosion on the connections. What do you think? Is it a very good chance that this is a Bad PCM?

 

Sorry for the delayed response - I haven’t had a lot of spare time to look at this again.

I need some clarification - you said you tried using a test light on the OR/RD wire and the fuse blew, but then in the next sentence you said it didn’t. It’s probably just a typing error but I isolated the quote that’s confusing me.

As for the wire being disconnected and preventing cranking and starting, yes, that’s totally normal. Any control module - be it PCM, BCM, HVAC, or other - must have all supplied power and ground feeds to be functional. The OR/RD wire is a direct battery feed which is what the PCM will rely on not only for memory, but also basic functionality. Think of it as the power button - when the wire is disconnected, the button is off.

I think it’s likely the PCM is at fault but if the fuse did blow when you hooked up the test light, then something else is at fault.

I don’t see where it’s been tried, but as a way to further isolate the PCM, remove the fuel pump relay, then hook up the PCM with the OR/RD wire in tact. Since the fuse is upstream of the relay, if it blows with the relay removed, PCM replacement is likely. But if it doesn’t blow with the relay removed, the relay could be shorted or there’s an issue with the fuel pump control circuits.

 

I Ordered the PCM from eBay and got it Saturday in the mail. I couldn't work on the car until today. I fixed the spliced OR/RD wire and as soon as I connected the battery the FP fuse did NOT blow. It used to blow immediately. Car now turn on and is working fine. I guess the PCM replacement I received back when the original was replaced may have been a repaired PCM and was probably not well repaired. This one is from a Junk yard salvage place that was reprogram with the VIN and miles. All is working well. Thank you for helping me out and for your wise advice.