[TrepLovin]

Turn on my lights, so my dash and head lights are on. Roll a window down or up, hit the break pedal, anything, I noticed my cluster will dim or flicker, my head lights will dim or flicker.

I understand that the power usage is high during all these points, but the dimming and flickering seems rather excessive at the same time.

I noticed these quirks with my original 2.7L motor. I just assumed the alternator was becoming weak, or I had a corroding connection(s) somewhere that was causing a lot of resistance. That said, I complete a 3.5L swap, and I know everything mentioned is A-1 now.

Thoughts?

[Adpros]

12 gauge wire would probably solve most of that. Expensive though!

[Daytrepper]

Bad connections and/or a bad/weak battery are #1 cause of those issues.

I have solved them everytime over the years by either replacing the battery or simply cleaning all the connections up. Our cars are quite sensitive to bad connections. You may have accomplished just that during the engine swap.

[TrepLovin]

I have some (believe to be) 12Ga wire laying around, more then an Intrepid length or so.

Any suggestions where I should be cleaning up specifically?

[Adpros]

Dan's suggestion was the only serious one... Starting at the battery is a very good idea. My Silver 01 2.7 had an insecure connection at the point where the battery lead connected to the terminal end of the battery terminal. The car would start and run OK but had odd lighting and accessory issues. Also, the battery light came on a few times.

After replacing the alternator, I still had the same problem so I was about to replace the PCM when I finally saw the looseness of the connection, (Where it crimps down on the battery lead).

Replaced both cable ends and never saw another hint of the issue.

[peva]

Also check that the connection of the 3 cables at the positive jump post is tight. Some years ago, I had flickering headlights and the problem was that the nuts on the jump post stud were slightly loose causing high resistance, which led to heat at the poor connection and flickering headlights and dash lights (connection between the battery pos. cable and the rest of the vehicle is the junction of those three cables at the jump post). Also check negative jump post (main vehicle ground).

[TrepLovin]

I know, I just forgot to punctuate my comment so it read sarcastically. :P

My battery terminal connections should be OK as I cleaned them all a matter of weeks ago when dropping the 3.5 in. But I'll check the connections to that boost terminals and then to the starter and alternator again. I did sand and clean the connections for the alternator and fuse panel though. Hence why I'm rather confused with the performance.

[peva]

Be sure to disconnect the neg. jump post before you put a wrench to the pos. jump post. If you don't, there is a high risk that your wrench will hit nearby grounded metal, and you will get lots of sparks and possibly a damaged tool (BTDT) or injury.

If you can spin the pos. jump post stud by turning one nut, then it is not tight enough. Put a wrench on both nuts and tighten them You might have to break the threads loose due to arcing and heat if the condition has been there a while - that was the case with mine - with a wrench on both nuts, it felt tight, but I realized that I could turn one wrench and the stud would spin - so I had to break the threads on one nut loose by holding one nut and backing the other one out - then retightening.

[DrDodge]

recheck all your grounds,, must be clean and tight

[Le Vinh]

I had the same problem with cluster flickering.
I replaced the battery and the flickering was gone. The other reasons could be:
- brake pedal switch (needs adjustement or replacing)
- headlamp switch (needs cleaning).