Need some help. My daughter has a 2006 Caravan SXT 3.3. About 3 weeks ago she tried helping a girl jump start her car. Well they hooked the cables backward. The cables started melting, smoke. They unhooked them pretty quick. My daughter van seemed fine. About a week later my daughters van started having trouble starting, having to have a jump. I knew nothing of this at his time. Well her van stopped on her in the middle of the road, this time she calls Dad, LOL. I get there and noticed her negative cable was melted about 4 inches down from the post. Also checked the battery had 3 dry cells. Towed the van home for her and went got a new battery. Went to her house and fixed the negative cable. Then installed the new battery. Got in van and turned the key on. At this point the lights work, the fans work, the radio works, windows roll up and down, horn works. When you go to start it nothing, No instrument panel lights, no fuel pump whine, no starter. Just a low clicking sound from the fuse box. Try swapping the starter and fuel pump relays. Nothing. Try jumping the starter relay with a wire, starter works turning the engine over. Try jumping the fuel pump relay, the fuel pump works. Put everything back. try at the key again. Nothing. That's about where I'm at. Any help will be appreciated.

 

Have you noticed if the security light is on or flashing when you try to crank the engine? Have you tried to pull any trouble codes? The CEL doesn’t have to be on for codes to be stored.

Given the circumstances, I suspect there’s probably more damaged wiring. If jumping the relay terminals runs the starter and fuel pump then the issue lies with the control side of the relays (pins 85 & 86). You need to know whether or not you’re getting voltage to them.

With the key in the cranking/start position you should see battery voltage at pin 86 of the starter relay. With the key in run or start you should see battery voltage at pin 86 of the fuel pump relay. Both relays receive power to the control side of the relay from the ignition switch which is powered by fuse 23/battery voltage in the fuse box.

The fuse box is actually a control module, so if you’re not getting battery voltage to pin 86 of those relays then you’ll need to remove the fuse box and backprobe the connector to see if you’re getting power to the module from the ignition switch. Let me know what you find with the readings at pin 86 and if necessary I’ll get you the info you need to check the right wire going into the fuse box (Dodge calls it the totally integrated power module).

 

Ill check those. I go back to my daughter house tomorrow and will let you know. I was told that maybe the Multifunction Control Module might be shorted out.

 

Well I knew I had a multimeter but could not find it last night. I went ahead a removed what I call the fuse box. Checked the box out itself and all the connections and fuses and relays and everything seems to be fine. Nothing looked burnt or melted. I kinda think its not the key/ignition switch because when I turn it to start I can hear a clicking noise in the fuse box. I'm ordering a Multifunction Control Module, can get one pretty cheap. Will post back and let you know the results. Thanks for the help

 

Yep. Let me know how throwing random parts at it works out.

 

How was I being rude?

 

Hey GumbyRT. 4th generation 2006 minivans do not have TIPMs. It has an IPM or Integrated Power Module....that's the fuse box with a Front Control Module (FCM) bolted to the front.

Hey Gravity. What is a Multifunction Control Module? Cold you mean a Powertrain Control Module or PCM? If your starter relay is clicking the PCM is sending the ground to it.

 

I was looking at the wiring diagram on pro demand.com when I referenced that - they colorize the diagrams and add a few user friendly features so it’s not directly from Dodge (although OEM diagrams are available). On there that’s what they called it.

 

When I said the Multifunction Control Module, I meant the Front Control Module on front of fuse box. I replaced that, didn't make any difference. Put the old one back on. Pin 86 has no power when in the run or start position. When I say no power how exactly am I supposed to check them with a multimeter. On the starter or fuel pump 86/85 do I put the positive post on the multimeter in the 86 and ground it to the battery or put one in 86 and the other in 85. I'm old school here, know nothing about this computer stuff. The last car I build was a 79 Z/28. Put a 4 bolt main block, 461 double hump heads bored out valve seats and spring seats, oversize springs, 202/160 valves and solid lifters, crane 292 solid lift cam. Comp roller rockers, single plane high rise intake with a holly 750 DP. Plus redid the whole car down to the frame. Wiring and all. But this crap has me stumped.

Like said the point I'm at, with the key on run, everything works but NO instrument panel lights and nothing when I turn to start. But starter/fuel pump works when jumped from the relays. I replaced the FCM from the same year, model and engine. Nothing. I've checked every wire, connector I can see from the ignition to the fuse box and engine compartment.

Thought about replacing the ignition switch. My Mother gave this van to my daughter and she had a paper route and turned off and started this van probably 5000 times. My daughter said the switch has been rough to turn from time to time since she had it. Can get a new one for like 20 bucks, so no big deal. But that's about where I'm at. Thanks

 

It's easy to get overwhelmed by all the computer stuff, but it's really no different than troubleshooting any other electrical circuit. Often times, when there's a specific event like this that has triggered the problems, solving one of them will usually lead to the solution for the others. So for now let's just focus on getting the engine to crank using the key, then worry about the fuel pump and cluster lights.

The only role the PCM has in starting the engine is grounding the control (coil) side of the relay. As you stated before, the starter will engage if you jump pins 30 & 87, so we need to find out if there's voltage getting to the coil side of the relay.

Having a helper to turn the key on and off when needed will make this much easier. Also, these tests can be done with a meter or a test light, but to keep from jumping back and forth between what you should and should not see with each one, I'm only going to explain the process with a meter. If you decide you want to use a test light instead, let me know and I'll explain the differences in what you need to do.

Normal current flow for this circuit is: Battery - Fuse 23 (10A) - Ignition Switch - Relay Coil (pins 86 & 85) - PCM

1) Check battery voltage - even if the battery isn't fully charged, it's good to know what voltage you're starting with because it can help narrow down the problem area to begin with. For the purpose of walking you through this, I'm just gonna say the battery is at 12v.

2) Remove the starter relay.

3) Red lead to pin 86, Black lead to B- or good ground. With the key in the crank position, you should see 12v (variation of 0.2v is acceptable)

4) If you don't see 12v on the meter, probe the test terminals on Fuse 23 (every blade type fuse has little spots on top where the blades are exposed - these are very convenient for quick testing). Keep the meter grounded - you should see 12v at the fuse - make sure to probe both sides to verify the fuse isn't blown.

Fuse 23 receives direct battery voltage, so if you see 12v then the problem is isolated to the circuit between Fuse 23 and Pin 86 which consists of the ignition switch and wiring. The next step would be to access the ignition switch wiring and determine if the problem is isolated to the wiring or the ignition switch itself. The wire from Fuse 23 to the ignition switch is Light Blue with Red stripe. The wire from the switch to the relay is Yellow.

5) With the meter grounded, use a pin to back probe the connector at the ignition switch on the LB/R wire - you should see 12v. If not, there's an open/high resistance between Fuse 23 and the ignition switch.

6) If you have 12v in step 5, back probe the Yellow wire. With the key in the crank position, you should 12v. If not, the ignition switch is the problem.

7) If you have 12v in step 6, the last thing to test is the circuit between Pin 85 and the PCM. This can get tricky just because there's always potential for the PCM to be damaged, so let me know if you get to this point and I'll explain further what you want to do as I'm running short of time at the moment and need to wrap it up.

Good luck.