Hello, I am new to to this forum so please excuse any mistakes I may make in etiquette. I own a 2005 f150 STX 4.6 and all of the lights are pulsing/surging, nothing major or dangerous but it is driving me insane. I have already cleaned all the grounds, and installed a new battery and "reman" alternator. The surging is worst at idle in gear but is noticeable while driving. Any other suggestions would be greatly appreciated as this is absolutely driving me up the wall and I am fresh out of ideas. Thank you

 

Don't change any more parts until one fails a published test. Then make sure the replacement passes the SAME test. What brand battery did you get, and from where? Did you read the date code on it?

Click these & read the captions:

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Check for a high resistance in the battery sense circuit, pin 3 of the regulator connector, OR/LB wire.

As a test, make a 10A fused jumper. Back probe the sense wire at the connector with one wire, then connect the other to the generator B+ output. If the voltage hunting stops and the charging voltage stabilizes at an acceptable value, you've identified the concern.