No Power to Fuse 7-12

[Esteban]

While working on cleaning up some wiring in my car, I somehow managed to make an unintended change that has resulted in no power to fuses 7-12 which obviously caused a host of other issues.

 

I believe this happened after I removed then re-installed my fuse box but am not certain. 

 

Any pointers on what could be the culprit here are greatly appreciated.

[jgerock]

Remove the screw that secures the fuse box to the car, pull up on the fuse box and see if the wires have come off the fuse block.  Make sure to disconnect the battery first.

[Esteban]

Thanks @jgerock I checked that and didn't see anything obvious. Everything looks to be well connected. 

 

Is there something that could knock out power to the entire right side of the fuse box?

[Mike Self]

Is your car a 12 fuse squarelight?  If so, check to see if fuses 7-12 service circuits that are either live only with the ignition on, or only with it off.  IIRC that's the way 12 fuse 02s are set up.  Whith this setup, there are two primary leads to the fuse box--a wire that's live all the time for those items that work regardless of ignition on/off (like tail lights, license plate lights, dome light etc), and another that runs through the ignition switch for all the other items (wipers, brake lights, etc) that only work with the ignition on.  Thus you may have disturbed one or the other wire when you had the fuse box out.  

 

mike

[Esteban]

@mike thanks for that info. Some digging on this forum and looking at the wire charts confirms that you do remember correctly.

 

I haven't found the source of the issue, but for the time being, I'm running a lead from the battery to fusebox. I just have to remember to disconnect it when I shut the car off until there is time for the real fix.

[jimk]

On 7/1/2019 at 8:22 AM, mike said:

two primary leads to the fuse box--a wire that's live all the time for those items that work regardless of ignition on/off (like tail lights, license plate lights, dome light etc), and another that runs through the ignition switch for all the other items (wipers, brake lights, etc) that only work with the ignition on

The live all the time one direct from the battery is RED (no white stripe).  After the fuses, those will be RED/WHITE stripe (hot all the time but fused).

The one from the ignition will be GREEN (no white stripe).  After the fuses, those will be GREEN/WHITE stripe (fused - ignition switch on).

Ignition switch out to coil is GREEN (non fused).  Don't want a fuse to shut you down.

BMW used the same coloring method on other cars.

Edited July 4, 2019 by jimk