Rep Power: 367

some of our cars are getting very old, so wiring health is important to check. Also, previous owners/mechanics could have done a hack job and they could be undoing themselves. Heat will reduce conductivity and make poor connections worse. You will need to check things yourself, unless it is a very common occurrence on the generation of your car.

First off, try to get a repair manual - they have electrical diagrams.

*not complete, still under construction* - feel free to add more tips, BTW.
Questions will be removed from this thread to keep it clean as a guide

• Check fuses
  • don't just look at the fuses, pull them out and check.
  • there are two boxes, one under the dash, another in engine bay, check both
  • don't know which fuses to check? Don't let this hold you back, how many fuses are there anyway? Check all

• Check grounds - there are three main grounds
  • if loose, tighten
  • if dirty, remove and clean
  • if wires damaged, fix them

• Check if wiring is not damaged where they are visible.
  • It's very common that critters/rodents get under the engine bay and make nests - warm environment during winter... They will chew the wires

• Battery draining
  • Have someone check the health of (Autoparts stores can do this)
    • Battery
    • Alternator
  • With multimeter, check draw at each fuse in the fusebox
    • keep all power off
    • pull fuse out
    • put multimeter and connect
    • check if there is current draw
    • if draw found, start checking that system's wiring - most likely something is damaged and shorting

• intermittent electrical issues, dash suddenly lightining a Christmas tree with multiple check code (VSA, EPS usually in there) (8th gen and above)
  • Low electrical power wrecks havoc on electronics.
  • Loose grounds
    • remove, clean and re-tighten
  • loose battery terminals
    • don't just look at them - remove, clean and re-tighten
    • one member found out a hidden bolt that was not tightened, that's why we say remove
    • if corrosion (green/blue-ish material accumulation), clean them
  • Not charging - need to check why
    • autostores can test alternator
    • note that aftermarket alternators are famous for not working properly on hondas
  • battery failing
    • auto stores can test batteries
  • wire harness damage (rodents again)
  • parasitic draw

• 7th Gen cars ECU does not connect, alternator does not charge
  • Check if your alternator bolts are tightened.
    • When loose, the alternator have poor ground and the intermittent connection will fry the ECU!
  • ELD can cause not charging. One member went to a junkyard and pulled as many LED as he could get and installed them until it worked.

• Door controls not working (power windows, power locks)
  • Don't jump into new actuators!!!
  • the wires at the door hinges could be damaged.
    • Constant open/close will stress the wires at the hinges and get damaged
    • open the door as much as you can, pull boot and start inspecting
  • wires OK, you can start checking other items.