Dash and headlights constantly flicker

jsnh1964

2005 Dodge Stratus, All lights will flicker really fast. Car runs beautifully, no problems except the dash lights will flicker really fast, the radio light will go out (but never resets the clock time) the headlights will flicker just like the dash lights.
I just replaced the alternator with a brand new on but nothing changed with the flickering lights.
Someone told me it could be the voltage regulator which they say is in the PCM in that car. I looked online, the symptoms of a bad PCM doesnt seem to be flickering lights. Everything I read online points to an alternator, which I just changed.
Before I changed the alternator, I had the battery tested, it showed that it was keeping a charge but it was giving a error saying that the battery cables were loose or they were being wiggled. Doesnt make much sense to me but I am confused as to what to do next.
With the car running perfectly, I am not sure what can be the problem
Anyone have any suggestions? and if it is the PCM, where it is located in my car?
Any help is appreciated!
Thanks

Mr_Shiftright

You might try cleaning both battery terminals and the battery posts thoroughly, and the other end of the battery ground cable as well. Also the engine-to-frame ground cable. Once that's done, and if there is no change, you might put a VOM meter on the battery posts to see if in fact you are getting rapid voltage fluctuations. The alternator can be bench tested (be sure all the connections are tight to the alternator, and especially double-check any connectors). Testing the PCM might require a more expert diagnosis.

thecardoc3

The headlights, parking lights and dash lights are controlled by the body computer. The alternator output voltage is directly controlled by the PCM. To narrow down where the failure is occurring with the headlights on and the failure occurring, voltage measurements should first be taken at fuse #10 in the junction block at the left end of the dash. This will separate the circuit before that fuse block assembly as compared to after it. A scope is a better choice than a voltmeter because of how fast it displays voltage changes. A test light could work since you might be able to observe the change in the lamps intensity, identical to what the headlights are doing.

If the voltage is changing at this point, go back to the battery and see if you can measure the same condition. You might even try going from the battery positive post to the engine block for ground, and then to the body. Note the points that show the voltage fluctuation, and which ones do not.
Repeat that with the voltmeter/test light/scope connected to the output terminal of the alternator and to the battery negative. Then move to the fuse block power connection, again notate where you see the voltage changing and where you do not.

The other possibility was that at fuse 10 (under the left hand side of the dash) the voltage was not changing while the headlights were flickering. Now move and re-test at the fuses for the headlights in that fuse block assembly, numbers 2,3,12 and 13.

Depending on what you find with these initial checks we will have a sense of direction to test further.

jsnh1964

Thank you for the suggestions. I will look at it this weekend. Is it safe to drive until I can figure out the issue? It runs nice and there is no issue except for the flickering lights. I did notice the battery light will come on after it is driven for a little while, but it still runs great and it doesnt drain the battery at all because it still will start right up.

jsnh1964

UPDATE: Drove the car last night, had the headlights on and was running the heater and when I turned the heater fan up high and all the light stopped flickering! I turned the fan on low and it started flickering again. So why would that happen? Makes no sense to me!..would that be the voltage regulator?

thecardoc3

It needs to be measured and proven, no matter what it is. Without any testing one could only guess at any one of the multiple potential sources for similar symptoms.

stephiann1983

I know this is an older post, however, I am curious if you figured anything out? I have a 05 Stratus SXT that does this, and has for almost two years. The dodge dealer has replaced the alternator 4 times, I replaced the battery, they checked all the body grounds, and they replaced the PCM this past January. The car did well until the beginning of March. They "state" they cannot replicate the problem, but i picked it back up and it keeps doing it. It is not constant, but only if the headlights, heat, radio, and sometimes it has to be the wipers.... I am at a loss and fed up!!!!