Hi! I'm new to the forum so hopefully I post this info in the right place.

I have a Dodge Grand Caravan Sport with a 3.3 engine that has recently developed a weird problem. The headlights come on by themselves.

The first time I noticed it was after a recent heavy thunderstorm about two weeks ago. Afterwards the headlights, turn signals and brake lights were on by themselves. When I opened the driver's door the chime came on but there wasn't a key in the ignition. After several minutes the lights would go off and then back on. This lasted for several days after the storm (which probably has absolutely nothing to so with the problem).

Fast forward to last night. Another very heavy thunderstorm and several hours later I noticed the lights were on again but dim. I was able to start the van and let it run but the chime again came on as I entered the Caravan. I ended up disconnecting the negative battery terminal until this morning.

Connecting the negative cable this morning the chime and lights came on again, as I expected. I started timing it. The "on" timing cycle was always exactly three minutes long then the headlights would go off, usually without any exact timing. One time they came on again after five seconds, another time five+ minutes aft4er the off cycle.

At one point I removed the Relay and fuse box cover and pressed down on every fuse and relay. When I pressed the cover back on with a bit of force the headlights came back on for again three minutes. The relay can be heard "clicking".

Any guesses as to whether it could be a relay, fuse, or headlight switch on the dash? Maybe something else? Thanks for any help!

DLA12

 

My guess would be the PDC (fuse box). They've been known to have corrosion problems. Might try inspecting the bottom connections and removing it and opening it up for a look see. Power is always waiting at the relays. They are just looking for a ground to turn them on. The high beam relay gets it's ground the old fashion way, a switch connects the ground. The low beams are higher tech getting it from the switch that applies a bias in a microprocessor in the body control module (BCM).

It's starting with a rain shower. What component is position where rain can effect it? The PDC. Everything else is in the cabin.

 

I just tried twice to reply to the thread and it didn't work...

 

Thanks for the quick reply Cougar41. Here's what I've done so far:

I removed the battery and then the air cleaner housing. I then removed the battery tray with three 12mm nuts and one bolt. I removed the two ground wires under the battery tray cleaned them with a wire wheel on a dremel tool and reinstalled them, then reinstalled the battery tray and air cleaner housing.

I then removed the two wires going to the PDC and cleaned both sides of the flat terminals, then removed the two 10mm bolts to the PDC. It then hinges upward to the left which is when I saw two things. The first was old black electrical tape placed around the orange and green wire connectors, the orange is for the low beam relay. I added new tape to both.

I then noticed a two wired plug with old tape, probably factory installed, near the furthest mounting bolt on the PDC. The plug wasn't plugged into anything and I couldn't see anywhere where it could have come out from so I replaced the tape and then mounted the PDC back in place.

I then removed the low beam relay and noticed some brown staining on one of five plugs. I cleaned it with a wire brush and replaced it. Reinstalled the battery after cleaning terminals and wires and it started fine. I took if for a short test drive and when I returned the lights did not come on as they have been.

Right now it seems fine but I'll have to wait until I do more driving and, of course, the next rain storm. I really appreciate your help and I will report back here if the problem is solved or returns.

Thanks Again!

DLA12

 

Nice work. Could you tell what purpose the tape was serving?

If needed later: the low beam relay coil ground comes into the PDC at connector C3 pin 7 (orange/white wire); the relay output contact grounds come in at connector C5 pin 8 (violet) for the left headlight and connector C3 pin 1 (violet/red) for the right headlight.

 

An update:

Yesterday all appeared fine when I drove the van for a short test run maybe a half mile. I drove it to my shop about 3 miles away this morning and all driving appeared fine. However, while on my way there I noticed I didn't have a tachometer or speedometer. No radio either, everything else ran normally.

When I got there I noticed the headlights were on again after arriving and went off after a short period of time although I didn't measure it. I then went to the gas station and the headlights were on and stayed on with the van running well after the three minutes but the tach and speedometer started working again and as said all else appears fine.

I drove it home and timed the lights again off again after three minutes from turning the van off. A few minutes later I reached into the van and hit the door unlock button to put something in the drivers side sliding door and the head lights came on again. Then off again after three minutes with the doors still unlocked.

This isn't my primary vehicle, it's a run around vehicle for errands so I'm not worried about major happening. I've had this van for about 8 months buying it after having to junk another 2000 Grand Caravan Sport that I purchased new in 2000 and junked it due to the front drivers side shock tower rusting out. I did strip out many, many parts for the van but I'm fairly sure I didn't take out the PDC. I know I took the relays and fuses though.

So, basically we have the headlights coming on anytime I unlock the doors or start the van then they go off in three minutes sometimes coming on by themselves again. Do you think I should remove the PDC and clean every terminal and relay with electrical contact cleaner?

I plan to drive it more to see if anything develops. Any chance there could be some type of reset for the van electrical? Could I have accidentally changed something with the remote? I highly doubt it but it was just a thought. Thanks again for any help!

DLA12

 

Also, I took plenty of pics of the work I did on the van yesterday. Can pics be posted here?

 

Update #2

OK, I'm a dumba$$ about the radio. I was pressing in the round button trying to turn it on when it has a small power button below and to the left of it. I pressed it and the radio came on...I didn't even lose any of the presets!

I drove the van about another ten miles. The headlights did not come back on. I'm not sure if it's the weather, it's warm with low humidity, or just the driving that may have solved the problem for now. Looks like only time will tell but I'm still going to check and see what parts I saved from the other van like the replays, fuses, etc. I'll just have to see how the van acts with more driving.

DLA12

 

Automotive electronics. Great fun......&#%#&#)#

Remove and clean PDC? It's worth a try. You've seen evidence of potential previous problems (tape) plus corrosion (brown contact). Did the tape appear to be an attempt to seal the connectors or was it there to hold the connectors in place? That brown contact could indicate water has dripped through and into the PDC.

Reset electrical? Disconnect the negative battery cable for 5 minutes.

" I did strip out many, many parts for the van but I'm fairly sure I didn't take out the PDC." Any chance of getting it back?

Post pics? Many post them on a picture hosting site like Photobucket then post a link to them here on the forum.

I almost don't want to mention this (and you may have read about it) as another possible cause because your symptoms don't fit the usual scenario but 3rd generation vans (96-00) are plagued with an all too common problem involving cracked solder joints on the instrument cluster circuit board. Typically they cause a combination of hard or no starts, VTSS alarm system faults, erratic instruments etc but the fact you lost your speedo and tach brings this up. The fix is to reflow the solder on the circuit board, specifically the solder joints securing the connector on the board.

What does this have to do with headlights? I may be stretching but here you go. Much of the electronics on the van are controlled by the CCD data bus. It's a communications circuit used by all the electronic processors (modules) on the van to interact with one another. The instrument cluster is a main hub for the bus. The main controller is the Body Control Module (BCM). The BCM is what controls your low beam headlights. See the connection? A typical quick temp fix is to smack the dash above the instrument cluster. Might try it next time.

That brings up a question. Is it your low beams that keep coming on?

BTW - the red highlights are the forum not me.