01 T & C Headlights Flicker & Dim Down

[Cntrysthbst]

Wondering what the problem is with my headlights. At an idle they seem to flicker somewhat, not much. Driving seems fine and in the process of coming to a stop I can see the lights go dim and back to normal. Seems like when I take off from a stop they ficker at a higher rate. I had the battery and alt. tested and was told they are fine. Seems to me when the ac cycles they dim but doesn't explain the flickering. Ground? Any testing on the electrical I can do? Any help would be great, thanks!

[taillight]

First check for loose or corroded battery cables. Then put a voltmeter on the battery and watch the voltage when this happens. If the voltage falls below 12.6 Either the battery or the alternator needs further testing. If it is ok put the voltmeter on the headlights and try the same thing. You may have a bad connection to the lights. I have seen batteries test ok and still need to be replaced when this happens.

[Cntrysthbst]

Updating here, I put a mutimeter on the battery for about an hour and just watched. Voltage stayed about 13. AC would cycle and it stayed the same. This was at an idle. So I put it in drive with the brake on and turned on everything, windshield heater, seat heaters, lights, etc., and it still seemed ok. It maintained about 12.62 volts. Then one time the fan just turned on to high speed and thats when it dimmed, voltage went to 12.29 then back up to 12.63 again. All this time I listened to the fan slowly go up and down and no spikes. Even when the fan slowly went to high speed it stayed steady. It happened when the fan went to high speed without the slow increase. It just turned on high speed. Any ideals?

[RIP]

If the battery is 4/5 years old replace it. When they tested it did they perform a load test? That's the only true test to determine how healthy a battery is. Your low voltages point to the alternator. Should have been at least over 13 vdc. Closer to 14 vdc would be ideal. Before you do anything you may want to try another meter.

[Cntrysthbst]

Just went out and got another meter, same thing, seems alittle lower on the readings. The battery is an 09/06. I had 3 places check the electrical with a load test too, and all was good. I think their machines, well nevermind that. I was wondering how I'd find out what alternator I need to get, I think I have a 160 amp but not sure. Thanks for all your help, I do appreciate it.

[taillight]

Your voltage is to low like RIP said. Sounds like the alternator but a bad battery can make the alternator look bad. The parts store will know the right one to replace with. After you are done check the voltage again.

[notsure]

I have the same problem only when the van is running. dealer said replace Light Switch, I think it could be voltage regulator????

[Cntrysthbst]

Still trying to figure it out too. I replaced the alternator with a new one, and the belt. Battery is new, and replaced the starter too. Replaced the bulbs and cleaned all grounds. Cleaned all elec. connectors as well with elec. spray. Mine seems to mostly do it when I'm driving as well. I was told the regulator is in the PCM not the alternator. Wasn't happy about that cause the alternator cost me dearly and it didn't help. My PCM is new, about a month old or so and still have the same problem. I'm lost on this.

[Cntrysthbst]

It is better but it still does it just not as bad. Doesn't go as low, even the inside lights do the same, it's just not a steady glow, it's a real fast flicker. Any ideals? Thanks

[coolkat25]

Originally Posted by Cntrysthbst

It is better but it still does it just not as bad. Doesn't go as low, even the inside lights do the same, it's just not a steady glow, it's a real fast flicker. Any ideals? Thanks

Hi, Cntrysthbst. I posted this exact problem several months ago. I never got to the bottom of this problem. I mentioned this to my dodge dealer and they replaced the battery...........made little to no difference. Have you noticed that the lights (all lights-dash and exterior) DON'T flicker while the engine is Not running? Also, have you ever noticed that your blower fan for your heater/AC sound like it is fluctuating in speed( kind of like in rythem with the brightening and weakening of the lights?) voltage regulator or altenator??

I will do some voltage readings.

Any one??

01 GC sport
Thanks,
CK

[Cntrysthbst]

Hey coolkat, welcome. I finally got to the bottom of it.

A low battery can cause alot of problems, mine was reading 12.67 volts and advanced auto machines said it was good. Finally giving up I took mine to the dealer and they said it was not good. They replaced it and the headlights are almost perfect now. I still saw it flickering alittle on the left headlight when they were showing me the difference and found out I have a loose headlight thing inside the headlight, its the metal thing that somewhat covers the bulb. Will have to fix that somehow. OK, anyways,

Yes, I have noticed everything you mentioned. And alot more. Your inside lights and etc., are controlled through your BCM, the outside lights have there own module, on mine and yours the outside light module is right in front of the relay center, its a metal box. I would take it back to the dealer and have their machine check your electrical system. That diagnostic they run will check everything, even bad/weak grounds. The mechanic at the dealer flashed my BCM and it fixed all the inside electrical and dash lights, all are steady. Hate to say but if the outside lights still flicker that module will have to be replaced because they can't flash that one. I would not go replacing the alt/regulator. The alternator just charges the battery, nothing else. The voltage regulator is built into the PCM, the voltage regulator provides enough current to keep the battery at the proper charge. All the electrical loads, engine, lights, are pulled from the battery. The voltage regulator can not be replaced, you will have to replace your PCM if it is bad. Let me know if this helps and you need more info cause I'm going back to the dealer Friday and can ask more. I hope your dealer has good communication, and knows what they are doing, I've gone through 4 to get to the right one. So sad. They should be able to do all this for you in an hour, they did mine in less. He checked the system, flashed the transmission and BCM, told me my PCM needs replaced and additional software updates have to be done, and replaced the battery in 50 minutes and I didn't see him rushing at all, he's 54, grey hair, he just knew what he was doing. I would also ask them if your software is up to date on your PCM, cause even this can be causing your issues. I can get you touch with this dealer if you'd like, just let me know. Hope this helps.

[coolkat25]

Wow, Thanks Cntrysthbst, for your thorough reply. I know what you are saying about finding the right dealership/Mechanic to work on your vehicle.I have taken my van to the two closest dealers to my house.(not overly impressed with either). I guess you got lucky to have found the right mechanic. You mentioned the transmission being flashed. Did your mech. have updated codes for the transmision and the bcm? I have no idea if this has ever been done to this vehicle? I did have the van in for this complaint, but all they did was put a new battery in. The problem was still there, I might try a different dealership.

Thanks very much for your reply.
Also read about the IOD fuse, pulling it resets bcm.
Might give that a try

Thanks
Ck