[4th Gen : 01-07]: What parts of the dash does the BCM need to function?
#1
08-02-2023, 04:02 PM
What parts of the dash does the BCM need to function?
Hello, 2004 GC.... long story short, I messed with my instrument cluster, top cluster (signal and high beam indicator strip), light switch and power mirror switch and speakers and now have no brake lights, no turn signals no cluster, but I have a proper headlight switch function. What of the aforementioned parts are needed to have a properly functioning BCM? That is to say, what dash parts when damaged or disconnected, would stop a BCM from functioning?
short story long..... 2004 Grand Caravan 3.3 became a lovely home for some mice several months ago and the smell was unbearable. I found the home behind the wiper motor cowl thing at the driver's side and cleaned it out. The smell almost went away totally. I opened the resistor thing that sends power to the blower motor (right behind the glove box on the ductwork) and saw house insulation and "mouse home" things wedged all over the ac evaporator coils. My intention was to rip everything out and hose it up and down the line from interior vents all the way to outside. I carefully removed the instrument cluster, speakers, one huge vent thing, most of the center console and the minor stuff, but then I got down to the huge dashboard piece that wouldn't come out and in a fit of rage, ripped it out, not caring anymore about having a one-piece dash on a 20 year old rusty van. I see that in my incredible hulk episode, I broke the connection of the power mirrors and light switch and the thin top horizontal cluster thing that shows the signals and high beam. My main instrument cluster was already out, that wasn't damaged at all. Now, when I plugged everything back in, I fixed that top cluster connector, but I have no instrument cluster lights, no brake lights, no turn signals no hazard lights. My headlight switch works, as does the interior dimmer, my blower motor works but my power mirror control box was damaged. I know these things that do not work point to the BCM at the driver's side dash, but I see nothing out of place. I have a broken connection at the power mirror control, that's all as far as I can tell. I also left the speakers disconnected. Would no power mirror control and no speakers make the BCM give up and go on strike? I tried wiggling the connector at the main instrument cluster, I tried disconnecting and reconnecting the battery, I read about people having a separate wire at the positive terminal of the battery that supplies the bcm but I do not have that. Does anyone know which portions of the dash is critical to let the BCM function?
short story long..... 2004 Grand Caravan 3.3 became a lovely home for some mice several months ago and the smell was unbearable. I found the home behind the wiper motor cowl thing at the driver's side and cleaned it out. The smell almost went away totally. I opened the resistor thing that sends power to the blower motor (right behind the glove box on the ductwork) and saw house insulation and "mouse home" things wedged all over the ac evaporator coils. My intention was to rip everything out and hose it up and down the line from interior vents all the way to outside. I carefully removed the instrument cluster, speakers, one huge vent thing, most of the center console and the minor stuff, but then I got down to the huge dashboard piece that wouldn't come out and in a fit of rage, ripped it out, not caring anymore about having a one-piece dash on a 20 year old rusty van. I see that in my incredible hulk episode, I broke the connection of the power mirrors and light switch and the thin top horizontal cluster thing that shows the signals and high beam. My main instrument cluster was already out, that wasn't damaged at all. Now, when I plugged everything back in, I fixed that top cluster connector, but I have no instrument cluster lights, no brake lights, no turn signals no hazard lights. My headlight switch works, as does the interior dimmer, my blower motor works but my power mirror control box was damaged. I know these things that do not work point to the BCM at the driver's side dash, but I see nothing out of place. I have a broken connection at the power mirror control, that's all as far as I can tell. I also left the speakers disconnected. Would no power mirror control and no speakers make the BCM give up and go on strike? I tried wiggling the connector at the main instrument cluster, I tried disconnecting and reconnecting the battery, I read about people having a separate wire at the positive terminal of the battery that supplies the bcm but I do not have that. Does anyone know which portions of the dash is critical to let the BCM function?
#2
08-08-2023, 04:29 PM
Hiya Mirageman,
Sorry to hear about your unwanted guests
What I would have done was the same procedure for replacing the a/c evaporator and heater core/// (and while I put that much effort into getting there, I would have replaced both of those items too.
Step one, remove the steering column.
Step two, loosen the entire dashboard as a package and place it into the front reclined seats
...at this point you have full access to the airbox
Step three, evacuate the refrigerant and disconnect the lines at the expansion valve, remove the coolant heater hoses, then remove the entire plastic hvac air box to your workbench.
It is really not as bad as it looks and I can imaging you have probably a t least a day or two into this.
Many folks mistakenly start to disassemble from the cabin going forward to the firewall, and this will eventually work but to see how these are assembled in the factory, you will remove it as a assembled unit.
See at 5:00
I found this online a while ago and post it for folks who need it.
https://web.archive.org/web/20160905...ahoney/vanfix/
Sorry to hear about your unwanted guests
What I would have done was the same procedure for replacing the a/c evaporator and heater core/// (and while I put that much effort into getting there, I would have replaced both of those items too.
Step one, remove the steering column.
Step two, loosen the entire dashboard as a package and place it into the front reclined seats
...at this point you have full access to the airbox
Step three, evacuate the refrigerant and disconnect the lines at the expansion valve, remove the coolant heater hoses, then remove the entire plastic hvac air box to your workbench.
It is really not as bad as it looks and I can imaging you have probably a t least a day or two into this.
Many folks mistakenly start to disassemble from the cabin going forward to the firewall, and this will eventually work but to see how these are assembled in the factory, you will remove it as a assembled unit.
See at 5:00
I found this online a while ago and post it for folks who need it.
https://web.archive.org/web/20160905...ahoney/vanfix/
#3
08-11-2023, 08:03 PM
Thanks for that info, but my problem was not being able to contain myself and not caring enough to take it out as one piece, hehe.... I just NOW found out why no signal lights or any part of any cluster was not working. For whatever reason, the HAZARD light fuse switch was blown. I came across this on a google search and thought no way it's that simple, but sure enough, blown hazard fuse. Why it blew, I have no clue. Perhaps in my ripping out of the dash, I somehow cut into a wire and shorted it. The internet conversation that I came across with this was not based on a teardown of the dash, it was a person that jump started his van and for whatever reason the hazard fuse blew.... Another was a family that was driving in the middle of the night. Nice, right? I'm not even entertaining the thought of going in there and investigating this any further. I'm going to reassemble my dash as best I can and drive it as needed until early 2024, and then NOT re-register it. Hazard fuse... they paid some schmuck to design this so that the brake lights and signal lights and the cluster will not work if that hazard fuse is blown. What A GLARING oversight... as bad and arguably worse than those AWFUL bumper-mounted signal lights on Kias and Hyundais.