weird wiring issues with radio and dome lights

[Jeephazlett]

Is there anyone that might be willing to chat with me through some wiring troubleshooting? My pillar lights flicker with my music (fuse removed in dome light circuit) but radio cuts out when fuse is reinstalled to dome lights

[Pete M]

3 hours ago, Jeephazlett said:

Is there anyone that might be willing to chat with me through some wiring troubleshooting? My pillar lights flicker with my music (fuse removed in dome light circuit) but radio cuts out when fuse is reinstalled to dome lights

 

I started a new topic for you so more eyeballs will see it.    

 

what condition is your fuse box in?  any weird splices or wiring from a previous owner under there?

[Jeephazlett]

10 minutes ago, Pete M said:

 

I started a new topic for you so more eyeballs will see it.    

 

what condition is your fuse box in?  any weird splices or wiring from a previous owner under there?

Thanks. New to the forum format i appreciate the help. Fuse box looks good. The only wiring near the fuse box that seems off is the left rear speaker wires were cut. The fuses are all in good shape and no extra wires are added in to the panel or anything. The only “hacks” were:

-radio harness spliced to aftermarket radio

- harness for clock is cut in a few spots but capped

 

my pillar lights were missing when I got the truck. Got the euramtec lights and only got them to come one with passenger door open. No driver door or dimmer switch. Next day wife called and said they were on with keys out and doors closed with switch off. Pulled the fuse

 

go to reinstall factory rx170 radio. The radio harness matches the truck harness so no color coding needed except the truck harness had two solid black wires. (Not brown which I thought was black or antenna). Radio lights, display and functions all work and came on but no audio output. Disconnected black wire and tried the “other” black wire and everything works. I assumed the extra black wire was the radio chassis ground even though I thought it was odd that the chassis needed grounded and the pigtail had a ground in it (based of the diagram on the radio)

 

Now my b pillar lights flash to the beat of my Nevermind by Nirvana cassette with the dome fuse out. I inserted the 10amp dome fuse and the lights and radio cut out. I only have one speaker (left rear) attached to anything at the moment with an aftermarket radio wire. 

[schardein]

I'm pretty good with electrical.  You provide a lot of info.  But I'm having trouble wrapping my head around it.

 

Your dome lights receive power all the time.  They are controlled (turned on and off) through the ground circuit.  When you open the door, it completes the ground path.  When you twist the headlight switch knob full clockwise, you complete the ground path.  When you turn the light on at the light, you complete the ground circuit.

 

Pulling the fuse removes the positive power.  So if your B pillar lights are flashing along with the music, with the fuse removed, they are getting "12v+" power from somewhere, and it must be a speaker wire if they are pulsing with the music.  And, they are getting a ground from somewhere, because they should only have a ground when the door is opened, or the headlight knob is turned.  Or they are manually turned on at the light.

 

If the B pillar lights only work with the pass door, that points to a driver door pin switch being bad, or disconnected, or corroded.  But if twisting the headlight switch knob doesn't turn them on, that points to other issues.  The headlight switch should have a path to ground that is engaged when it is twisted.  Sounds like you don't have that.

 

It sounds like a speaker wire has been connected to a wire in the dome light circuit.

 

Do you have the factory under dash courtesy lights?  If yes, they are wired in the same "dome light" circuit.

 

You mention the left rear speaker wires were cut near the fuse box.  And the clock wires were cut, but are now "capped".  What does "capped" mean?  Hopefully not wiring nuts for household wiring.  Those have no place in automotive wiring.

 

I don't know if this helps any.  Just an explanation that may help you troubleshoot.

[Pete M]

my philosophy with complicated electrical problems is to start fixing everything that is known to be wrong and see what happens. 

[AZJeff]

9 minutes ago, Pete M said:

my philosophy with complicated electrical problems is to start fixing everything that is known to be wrong and see what happens. 

I second that philosophy.   In vehicles that have been owned my multiple persons before me, and I see ANY type of NON-FACTORY wiring, I almost invariably remove it all and start over.   So much stuff that is added in by first, second, third, and fourth owners is hacked up garbage that often causes problems that can be very mysterious (and possibly dangerous).

 

Several things that usually are clues to hacked wiring include:

1.  wires twisted together to create a splice (instead of crimped or soldered)

 

2. use of that junky/sticky vinyl electrical tape to insulate connections (extra negative points for using duct tape or scotch tape!)  The right thing to use is heat shrink tubing.

 

3. use of "wire nuts" intended for household wiring

 

4. use of "Scotchlock" connectors in under-hood applications, where they are exposed to adverse elements and can corrode.

 

5. any strange wires added to the fuse block by cramming them in behind the fuse blade.  (They actually make a gadget that allows you to tap into an existing fuse slot and still retain the existing fuse while making  reliable connection.)

 

6. any added circuits that get power that is unfused (talk about a fire waiting to happen.)

 

My recommendation to anyone with a vehicle containing this kind of stuff is to (1)get the factory wiring diagrams for your vehicle and (2)start trying to redo any connections that exhibit any of the above characteristics.

[AZJeff]

OP---what year is your vehicle?  I might have the wiring diagrams for the factory radio and the dome/courtesy lights that can help you chase down the issues you are having.

[Jeephazlett]

7 hours ago, AZJeff said:

OP---what year is your vehicle?  I might have the wiring diagrams for the factory radio and the dome/courtesy lights that can help you chase down the issues you are having.

88 MJ 

[Jeephazlett]

8 hours ago, schardein said:

I'm pretty good with electrical.  You provide a lot of info.  But I'm having trouble wrapping my head around it.

 

Your dome lights receive power all the time.  They are controlled (turned on and off) through the ground circuit.  When you open the door, it completes the ground path.  When you twist the headlight switch knob full clockwise, you complete the ground path.  When you turn the light on at the light, you complete the ground circuit.

 

Pulling the fuse removes the positive power.  So if your B pillar lights are flashing along with the music, with the fuse removed, they are getting "12v+" power from somewhere, and it must be a speaker wire if they are pulsing with the music.  And, they are getting a ground from somewhere, because they should only have a ground when the door is opened, or the headlight knob is turned.  Or they are manually turned on at the light.

 

If the B pillar lights only work with the pass door, that points to a driver door pin switch being bad, or disconnected, or corroded.  But if twisting the headlight switch knob doesn't turn them on, that points to other issues.  The headlight switch should have a path to ground that is engaged when it is twisted.  Sounds like you don't have that.

 

It sounds like a speaker wire has been connected to a wire in the dome light circuit.

 

Do you have the factory under dash courtesy lights?  If yes, they are wired in the same "dome light" circuit.

 

You mention the left rear speaker wires were cut near the fuse box.  And the clock wires were cut, but are now "capped".  What does "capped" mean?  Hopefully not wiring nuts for household wiring.  Those have no place in automotive wiring.

 

I don't know if this helps any.  Just an explanation that may help you troubleshoot.

This does help me understand how it works. I didn’t think to shut my doors when the lights were flickering. You gave me some things to check. The previous owners had wire nuts and electrical tape. Once I have this all sorted I’ll crimp and shrink tube it all. I’ll start by disconnecting the other three speakers wires one at a time and see when the lights go off.