Dash/Instrument & Running Lights Won't Turn Off

[ramit]

check back of radio bettin you'll find dash light with tied into a battery source most aftermarket radios don't require dash light wire so it ends up getting tied in with another wire

[JessEm]

Just taking a break from a solid hour of unraveling electrical tape under the dash. Not a HUGE surprise, but checking the tan wire to the instrument lights at the switch revealed it's ALWAYS hot:

I:  White/Tan wire for Instrument lights, should only be hot when the switch is pulled (any position) and voltage varies with turning the rheostat/knob. Sends power to the INST LMPS circuit on the fuse panel, and it looks like it takes a 2 (two) amp fuse.  Check this fuse carefully.[/size]

More wires to untape, then time to start tracing and see if I can find something spliced in. Man, I need to put a fan out there...

[JessEm]

The orange wire coming off the back of the fuse panel goes to instrument lights. The pink wire goes to exterior lamps. They looked melted together so I pulled them apart...




Nothing behind the fuse box looked tampered with, as in, it came this way from the factory.

I wonder which wire got hot enough to melt the orange? Or were the two wires arcing through the orange plastic?

At any rate, pulling them apart seems to have fixed my dash lights "Always On" problem...

Feel free to take guesses at why two wires that are not always hot, created a "always hot" situation..??  i?? ...It's only fair that you have all the variables... Last week, I cleaned every electrical connection inside my battery compartment and it fixed the "running lights always-on" problem. Go figure.

I'm thinking I may have returned that new headlight switch to the store prematurely, however. It seems there are "dead spots" in my dimmer. As I dim or brighten the dash lights, they flicker off as I'm turning, until I hit another "good" spot, then they come back on at the correct brightness. My multi-meter at the switch confirms that when it shuts off, the voltage at the tan wire drops to 0... Does this sound like a bad switch  i??

Here's a look at my current situation. I read somewhere that someone removed the front seat when working under their dash. Great advice. It's easy, and there's really no other way.

[pvoth1111]

see the color of the copper on the pink wire crimp as opposed the bright copper color on the rest.....loose connections cause heat cause melted stuff......I would use rosin paste and solder all of those connectors to make a good connection that will cause no more problems.....don't leave it like that...its not fixed yet.

[DaveVA78Chieftain]

The pink wire is from the INT LPS Fuse.

[JessEm]

The pink wire is from the INT LPS Fuse.

Dave, I'm thinking my fuse box might be different.  It's labeled (from bottom, up):

INST LAMPS 2A  (orange)
EXTERIOR LAMPS 20A  (pink)
INTERIOR LAMPS 20A  (don't remember color)

Unless you're correct, and they flip-flopped the orange and pink at the factory? I guess the only way to know for sure is follow those wires to their destination. ... But I have it buttoned up now and I'm not going back under there for that!  N:(

I wonder if the white wire has aluminum foil wrapped around the fuse W% ....You are really close to a fire, and I think you are really close to finding your issue now. Good info from PowerWagonWalt too

I did find the PO had a 30A fuse in the 2A slot. ... Maybe that explains why the headlight switch got hot enough to melt the plug. 

[DaveVA78Chieftain]

Opp's sorry.  Went back and looked at the wiring diagram again.  That was EXT LPS not INT LPS.

[M & J]

Whoops. That doesnt happen often.

[DaveVA78Chieftain]

 i??

[JessEm]

No prob. Thanks for clearing that up.

[PwrWgnWalt]

Glad to hear you found the issue and got it fixed!

The symptom you have with dead spots in the rheostat of the headlight switch is very common.  A new switch is likely the most effective solution for this issue. 

My guess is the orange wire got pulled up behind the pink wire (battery hot lead) during installation or other manipulation. Good inspection!

A few swipes with a little wire brush and some dielectric grease on every electrical connection and contact point can help avoid the voltage loss and high resistance of aged ( or new) connections.

Walt

[JessEm]

It was indeed a bad headlight switch causing the intermittent dimmer.

THANKS AGAIN PwrWgnWalt, and EVERYONE else who chimed in on the subject!! 

FYI, O'Reilly Auto sells the same Echlin headlight switch as NAPA for $2.50 less.


Now I'm in the middle of a little experiment. I'm leaving the MH's battery disconnect "ON", and checking battery voltage over the next few days. I'm just curious if there's any other draws, or if the batteries can now sustain a charge without the disconnect OFF.