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Power still on after I remove the key...sometimes

3K views 22 replies 7 participants last post by  Alvin in AZ 
#1 ·
I just finished up removing and replacing the dash in my 94 Bronco. Now im experiencing some unusual behavior.

Sometimes after I park the truck and turn it off and remove the key, my stereo is still on. It has never done that before. Also I noticed the wipers still work.

It just did it again and I noticed something that might be important. Once I removed the key, making sure the ignition was in the off position firmly, My stereo was still on. Then I turned the wipers on and then off. My stereo then went off. Could it be something going on with the MFS causing this?

I have no clue how the key switch works at all. Maybe one of you Bronco Genius's have a schematic for that or some pictures or some ideas of where I can look. I know I have everything hooked up correctly (at least i think so, because everything works)

Anyone have any thoughts on where I can begin looking to solve this little problem?
 
#2 ·
Check that your ignition switch (on the steering column, not the place where the key goes) is all the way in the off position, could be the rod is misadjusted.
 
#3 ·
Im sure its probly something like that. It would help If I knew where to look, guess im gonna have to go digging in Steve83's supermotors pages again. I should have all that memorized by now as many times as i look thru there.
 
#6 ·
Well I solved the problem. Believe it or not it was the headlight switch. My mod to mount the window switch to the dash caused the HL switch to protrude farther than normal past the instrument bezel. if you push the HL switch in too far, all the power comes on. When I pull it out a bit the power goes off. Simple to fix.
 
#7 ·
Then there's something seriously wrong with your h/l sw. It's designed for the knob's shaft to come all the way out (if you press the little button on the steel side of the switch). To put it back, you just push the shaft until the switch goes back to OFF, and then push harder to make it snap onto the catch again. The h/l sw. should never affect the radio or wiper power.
 
#13 ·
Bad idea. It's VERY easy to remove each terminal from the old shell & transfer them to a new (or just better) one. If a terminal is too badly damaged to clean, repair, & protect using electrical grease, cut & replace ONLY that one. Keep your cutting to a minimum - stock wiring is more reliable than butchered.
 
#15 ·
Well I got up the nerve to remove the headlight connector today. Good thing I had a replacement connector handy.

[/IMG]

It pretty much fell apart in my hand.


The problem appears to have been, The O/BK WIre and the G/Y wire were switched in the connector. When I replaced the connector and switch, and pinned it out the same way the donor switch was wired, everything works as it should.

[/IMG]
 
#18 ·
Well I got up the nerve to remove the headlight connector today.

The problem appears to have been, The O/BK WIre and the G/Y wire were
switched in the connector. When I replaced the connector and switch, and
pinned it out the same way the donor switch was wired, everything works
as it should.
Wow that's pretty cool. :)

What two circuits are those? :)

Alvin in AZ
 
#17 ·
I think its been like that since i had it. I noticed the little melted spot seen from the wire side the first time I took it apart on Day One.
Looks like the Tan/White wire and the Brown Wire somehow shorted together. I dunno, something got really HOT.

Amazing how brittle these connectors get over time. I Need to find a cheap supplier for them, maybe Clip & Fastner. Ill have to look.
Id love to change all my brittle connectors. I spent an hour int he JY yesterday Tracing wires in an Explorer.
Im gonna go back and get some wire to finish up my Autolamp Mirror.
 
#20 ·
yo J,
Inspect the switch carefully;
because;
Switch Fires, Part Number SW-2103: "...Over the past two years, this office has experienced fires caused by another potential problem in Ford vehicles. The problem exists within the dimmer portion of the head light switch in Ford vehicles. The light switch involved is a Model SW-2103. These are the pull out type head light switches usually located in the lower left corner of the front dash of Ford vehicles. The head light portion of the switch has two pullout positions, the first for parking lights only, and fully out for head lights and parking lights. The shaft of this pull-out light switch can be turned clockwise and counterclockwise which activates a dimmer switch, lowering and raising the intensity of the lighting in the instrument panels respectively. Fully rotating the shaft counterclockwise past a notch activates the interior lights within the vehicles. The potential problem exists within the dimmer portion of this switch. The dimmer mechanism consists of a metallic resistive coil set inside a ceramic disc positioned over the shaft of the switch. The coil is exposed on its front side away from the passenger compartment. The front side of the coil passes across a contact permitting a current to flow through a certain portion of the coil when the switch is pulled our in its first or second positions. The greater amount of coil through which the current is permitted to pass (clockwise most position) creates the greatest resistance and therefore dims the dash lighting to its lowest intensity. The opposite position provides greatest intensity. Through our investigations, we have found that the coil can fail owing to wear and/or possible material defects or damage. A fractured coil can maneuver itself free of the ceramic disc permitting it to come in contact with the metal bracket which mounts and grounds the switch to the vehicle. When this occurs, a current can flow through a portion of the coil creating high temperatures melting the metal material of the coil and possibly igniting surrounding combustibles. This mechanism has been observed in three separate incidents by this office. Two of these resulted in a fire. The mechanism is precipitated by wear and/or defect in the coil mechanism. If the former is true, we expect there will be an increase in fires caused through this mechanism given an increase in service time. To this date the problem appears to be somewhat limited. However, this particular light switch has been utilized in numerous Ford vehicles. Therefore, a small increase in failure rate owing to age and wear could result in a significant increase in fire losses. The SW-2103 Light Switch Assembly discussed above is reportedly installed in the following Ford vehicles: 1986 -1997 F100, F150, F300; 1990-1994 Explorer; 1987-1994 Ranger; 1987-1990 Bronco II; 1992-1997 Aerostar..." Source: by waltersforensic.com

Miesk5 NOTE: a shop or PO could have installed this particular switch design in other model year Broncos, see the Ford info below in the Buyer's Guide Results by FORD: Part Number: SW2103 Description: Head light Switch, Manufacturer: Motorcraft. Years: 1990-1994 Applications: 535: 1992-1994 Bronco; 1990 Bronco II; 1990 E-150 Econoline; 1990 E-250; 1990 E-350; 1990 Escort; 1991-1994 Explorer; 1992-1994 F Super Duty; 1992-1994 F-150; 1992-1994 F-250; 1992-1994 F-350; 1990-1994 F53; 1990-1994 F59; 1990-1994 Ranger


My 96 and according to Ford,
1995 Broncos and most if not all F series from 95-97 use Headlight Switch SW-5053

I you find coil is issue for the burnt connector body & terminal(s); Write to Ford & NTSB
 
#21 ·
Thanks Miesk, Dunno what initially caused the meltdown, but the dimmer coil was fine. I replaced the switch with one from a '95 f150. It was exactly the same as mine, so I dont think I had the SW2103 switch. Mine was identical to the '95, which according to your statistics is a SW5053.
 
#23 ·
...didn't know the connector could of been depinned at that time.
Cool, and for the others, just think...

"street sweeper broom straw" ;)

You don't have to walk very far in any city and you'll find a few of
those layin' in the cement gutter or on a large paved parking lot.

It's hard-drawn~1080 carbon steel not quite as springy as music
wire from the hardware store but is close to the same material
and processing.

Make lock picking tools or wire connection tools or... ?
File and/or grind 'em into the shape you need.

Alvin in AZ
 
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