How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask sprinkles08 Your Own Question
sprinkles08, Chrysler/Dodge/Jeep master tech
Category: Dodge
Satisfied Customers: 22295
Experience:  ASE Master and Advanced Certified, Chrysler/Dodge/Jeep Master Certified, Trans and Hybrid Specialist
Type Your Dodge Question Here...
sprinkles08 is online now
A new question is answered every 9 seconds

2002 Dodge Ram 1500: Wipers, Brake Lights, Horn, Headlight Control (

This answer was rated:

2002 Dodge Ram 1500 5.9L - Was driving along, panic alarm started sounding and lights flashing. Now, no longer have Wipers, Brake Lights, Horn, Headlight Control (comes on with keyswitch), outside temp display no data. No blown fuses, checked battery and in fact installed new battery. Pulled FCM and all connectors to Power Dist Box, checked for bad connectors best possible. Have a hunch the FCM may be freaked out but I am also thinking a circuit may have bad ground or bleeding voltage. Any suggestions?

Hi. I assumed you would have mentioned it but I'm going to ask anyway because the symptoms go together, is your instrument cluster dead too? If it is working, do the gauges work normally? Do you get a temperature reading on the overhead console (if you have one)?


Customer: replied 8 years ago.
The instrument cluster seems to be ok but the overhead temp display has multiple dashed lines, no read. Again, head lights come on with key but headlight switch is off. When headlight switch turned on, the dimmer has no effect. No wipers, horn, blinkers,or brake lights, however, the back of cab brake light does illuminate when pedal depressed.

Ok. It sounds like you may have a dead fcm or an internal problem in the ipm, the fuse box that it bolts to. There are mulitple printed circuit boards in there and they're prone to corrosion that can open up circuits on the board. I got burned on one of these yesterday. I replaced an fcm and it ended up being the ipm. You might have a dead communication bus too, the network all the modules talk on.


On a hunch, go out and pull the connector off the abs module. its on the driver's side next to the fender, you can't miss it. Unplug it and see if the problem goes away. If not, pull the fcm off.


Look at the ipm where the fcm was. You'll notice the top row of pins are flat and the lower ones are all round. Counting from the top right pin on the ipm, this is pin 1. With the key on check for power at pins 3 and 4, 6 and 7. Let me know what you find for all of this. We may have to break out the voltmeter on this one.


Customer: replied 8 years ago.

Thanks, XXXXX XXXXX has me baffled. I will perform as instructed but unfortunately it will have to be later, possibly in the morning. Will you be available for discussion and my findings on Wednesday?

Oh sure. I'm at work during the day but I do get to check in a couple times. I'm on all evening. I'll look for your reply, and if I don't get back to you right away its because I'm at work, but I'll respond to you as quick as I can.


Customer: replied 8 years ago.
Good evening, I pulled the connector from the ABS unit with no change in condition and checked voltage at pins 3, 4, 6, 7. All read 12 volts. Cleaned FCM pins and anything else within my reach. Not any results. Regards, Jimmy

Ok. With all of this going on together I really think you have a bad fcm. You've got all the power feeds. This is best diagnosed with a scan tool but we can try and go as far as we can with a volt meter or test light and some jumper wires. the bad thing is I don't have access to wiring diagrams for your truck until morning. The closest thing I have is 2005 until I get back to work. I can round up the wiring info for you and get back to you with some tests tomorrow if that's ok.


Customer: replied 8 years ago.
I understand, I have access to ALLDATA if there is anything you would recomend I take a look at. Regards, Jimmy

I wish I had access to Alldata, I've been trying to get that set up for a few days. Finally got a call back tonight...


Make sure all your grounds to the fcm are ok. Pull it off and check right at the ipm to fcm connector. I think you'll find them ok. Put it back together. check the voltage on the PCI bus wire at the data link connector under the dash with the key on and see where its at. Unplug the fcm (turn key off to unplug it, then back on) and recheck the voltage to see if it comes up or goes down at all. Let me know what you see there.


You can power up all of your light circuits right from the fcm to ipm connector. Power up the ones that you can do-headlamps, turn signals, brake lights. You can also ground the pins that turn on the relays for the horn, wipers, etc with the key on and those things should run.


Let me know what you find for everything and we'll go from there.


Customer: replied 8 years ago.
Thank you, XXXXX XXXXX give it go and let you know the results. Regards, Jimmy

Sounds great. Good luck!


Customer: replied 8 years ago.

I bought a FCM. Everything leads me there, as well. Have not installed yet. Do I have to take to dealer for VIN data input before unit will work correctly? I am not too knowledgeable on Dodge systems, VW is more my bag...Jimmy


The fcm is where I was leaning too but I didn't want to pull that trigger with your $220 without at least checking powers and grounds. The IPM's do give some trouble on these too, there are some corrosion problems on the circuit boards.


You don't have to do anything but screw the thing on. There is no programming or anything like that, screw it on and its ready to go. No scan tool necessary. Have the key turned off when you plug it in. Let me know how it goes...

sprinkles08 and 4 other Dodge Specialists are ready to help you
Customer: replied 8 years ago.
I will install shortly...pulled a few drawings off ALLDATA for the 02 Ram, are you interested in them for your files, would you want me to email them to you? jimmy
I'm actually a dealer tech, so during the day I've got anything I could ever want. My Alldata rep is getting me set up now so I should be up and running in just a couple more days. Thank you very much for the offer!!
Customer: replied 8 years ago.
you bet...Let me install the fcm and I will accept. Hope all works....

Sounds great. I'll be tied up for a little bit here but it shouldn't be long and I'll be back for the rest of the evening.


Customer: replied 8 years ago.
FCM fixed the problem. I had forgoten about the fog lights not working, they are even back up and working. Thanks for all of your help! Jimmy

Beautiful! Glad to hear it. Thank you for the accept, and thank you for using JustAnswer!