I could use some help with some recent electrical issues. there is a circuit that has the tail lights and the hvac back lighting on it and that fuse keeps blowing. It happens as soon as i turn the ac on. makes no sense since the ac and the tail lights on on separate circuits. also, when i turn the headlights on the drivers door lock actuator makes a clicking noise but doesn't actually lock or unlock the doors while making the noise. and lastly the instrument lights and radio go blank when the headlight are turned on. is there a component or module that is tied to all of these things that could be failing? Is there a way to test that component? Any help with this would be greatly appreciated. This is a car that runs well but has high miles and isn't worth putting the money into having the dealer diagnose the problem.

 

How much more of a visual and hands-on inspection have you done thus far? Have you inspected and cleaned all of the ground circuits? Or inspected the backside of the fuse block? Done any pull tests? Start simple and work from there. Thoroughly going through the chassis may present the issue, sometimes that's all it takes and can save you hours of chasing wires and modules with a DVOM. Let us know if you're still stuck after that and we can run through the wiring diagram. Good luck

 

I can think of two possibilities.

First, poor grounds can cause all sorts of weird electrical issues. It's not uncommon on the Fit, I gather, for the main battery ground connection to the frame to get less than solid with corrosion etc. over time, which could possibly cause at least some of these symptoms.

Second, maybe there have been mice or other critters chewing on the wire harnesses somewhere, and there are (possibly intermittent) shorts.

 

Thanks for the replies. I should have mentioned that I've already had a mechanic from an independent shop spend a couple of hours on trying to diagnose this problem and he thinks it could potentially be the gage cluster, the fuse box and found no bad grounds or fried wires.

 

I had a similar problem with my Volvo. It was an intermittent short where the wiring flexed as the boot/trunk lid opened and closed.

 

the guy that looked at the car checked all of the grounds and wires that are accessible. after digging into this more online and talking with a very helpful Honda dealer parts guy He thinks that based on my symptoms I need to look at the possibility of it being the multiplex controller. It's the computer that's integrated into the interior fuse box. He's never heard of one going bad on a fit but they do go bad on other Honda's. Has anyone on this site had to replace one?

 

what was your resolution ? I have having similar issue and mechanic says interior fuse box bad. I am not finding the part online.