Hi everyone,
I am having a problem with my 1999 dodge grand caravan. A few days ago, my driver and passenger door lock switches gave out. The problem is pretty non-intermittant, I would say that they randomly work once every 200 times I press the button. The key fob unlocker works perfectly, and I don't think the actuator is the problem because they would have had to all go out at the same time and the locks manually open and close easily.
Then, yesterday, I went to start my car and the gas gauge read empty. I went to fill it thinking I may have forgotten how much fuel was in there, but it still reads empty. Since then, I've started my car about 10 times and a few of those times (maybe twice) the fuel gauge worked normally. Once, while I was driving it, the fuel gauge kept dropping to zero, then going up to about a quarter tank after a minute, and then after another minute dropping back down to empty. At the time, my tank was at least 3/4 full.

Now that I think about it, my dash lights have been flickering a little bit over the last few weeks. Not a lot, and I didn't think anything of it at the time, but... probably related.

So far, I've tried taking the door/lock switch panel thing off of the drivers and passengers door and cleaning the contacts leading from the harness to the switch... no change. I tried leaving my battery disconnected over night, I used a scan tool to check for codes, I did the trip/reset code test thing and got no codes on either. My battery seems to be running with good voltages, I've checked all fuses for breaks. I tried that trick with the IOD fuse where you flip it, and that didn't help. I even replaced the IOD fuse with a new fuse, but these problems are still there. Any help or advice would be appreciated... I think my research is pointing to it being the BCM, but some things I've read have indicated to me that I should be having all sorts of problems if my BCM is bad. I'm really just having problems with the door locks and gas gauge. I assume it's not just them both going out independently since that would be weird, and both door locks gave out, and both problems are kind of intermittent.

What do you think? Could it be the BCM? Is there something else I should try, some fuse I should triple check, some trick that may help?

Thanks in advance!

 

Yup. I'd have to agree your BCM is in the spotlight for your door lock problems. The entire BCM doesn't necessarily have to stop working. Individual circuits within the BCM can malfunction while others work ok. The fact they lock and unlock fine using the key fob but not with the door switches is an example. Both modes us the BCM to operate the door locks. That same fact eliminates all three relays involved. Only thing left is the BCM or the switches. Then there's that pesky wiring. Just to CYA verify you're getting the switch input at the BCM using a multimeter. Disconnect the negative battery cable before disconnecting the BCM.

Your fuel gauge is another all too common issue. Based on scouring forums for many years I can say somewhere around 4 of 5 times someone reports a fix for it they change the fuel pump assembly in the fuel tank. Other times it is a wiring problem or the gauge is bad. The fuel sender for the gauge is part of the fuel pump assembly. The BCM does play a part in the circuit but it is rarely the source of the problem. You can test the gauge using the instrument cluster test.

 

I see. Thanks for the reply! I was under the impression based on other sources (nothing too reliable... yahoo answers, etc) that the door lock and gas gauge combo was decently common and was usually the BCM, but it sounds like this is just a coincidence. I will look into both solutions you mentioned and post back! Thanks again for the help!

 

Hi,
My 99 Dodge Caravan is having the exact same issues, my gas was already very low, but when I got into my car, I noticed that my lock buttons weren't working and then after putting $30 of gas in, the gauge still read empty. Then on the drive home, the dash lights were flickering.

What ended up being your problem and do you remember how much it cost to fix it?

 

Maybe we can start a club! I recently post the same issues. One exception is that on occasion the fan switch does not work. Very frustrating, but at this time I can live with the issues. They always begin working within an hour or so. Also, the only issue I have noticed in the last 3 or 4 weeks, is the odometer and transmission dash lights flickering. I hope we find a fix!