headlights blinking

[devildog95]

hey everyone hope everyone is doing well......having an issue with my headlights . when on low beams they blink  .its both lights at the same time blinking. its not  a constant on and off . they may be on then all of a sudden. they will blink. .when I put the high beams on I don't have this problem. then this morning my left headlight was really dim then it got bright again. another thing I noticed  is when I shut the hood they blinked. im thinking maybe the headlight switch and or the connector.  thanks mike...............

 

[Rons beast]

Hey Mike,

check the ground to the headlights as well.  Often the copper wire is corroded even up the wire under the insulation.  I have replaced the grounds with new wire on all my older cars.

Good Luck

 

[devildog95]

thanks ron for that info.does each headlight have its own ground? this looks like its going to be a hard job too find where the grounds connect to the fame or where ever it may be leading.........

 

[Rons beast]

Hey dog,

there is a ground wire to each light that is part of a bundle. That could be hard to trace.

What you could do is locate the black ground at the easiest headlight to get to. Splice in a new  #16 wire and run it to a new good ground.

I created a new "Master" ground spot by running a #10 wire from the battery(-) to a spot on the fender and added a bolt "Lug" to attach other ground wires.

Now you have provided a new ground source for everything on that circuit.

If the headlight closest to that splice works well but the other is still a problem, then you have to wire in new ground wires to both. The wire between both lights is degraded.  It may be time for a rewire.

Good Luck 

 

[devildog95]

dude you are the man..........what a great idea..when your referring to' lug it in' are you saying like drill a hole in the frame clean the area good and connect ground wire their with a bolt and nut?  also couldn't I splice both ground wires from  each headlight and ground them together? I just don't understand when the high beams are on I don't have no blinking .thanks mike

 

[Rons beast]

Mike,

yes, when I "lug in" I place a bolt through a clean hole in good metal. The bolt is longer so I can  use a nut to anchor it, then use another nut to hold the wires. Then I'm not losing the bolt or nut when I need to add or remove a ground.

it's ok to splice both headlight grounds together. 

The fact that you say they don't blink when the high beams are on make me think Headlight switch or relay.

Good Luck

 

[devildog95]

thanks for that  info ron. this weekend im going to take your advice and redo the ground wires from  the headlights put a new switch in and connector if it looks fried... ron I really don't mean you bother you again because you been so helpful.but where can the headlight relay be located at ?. when it comes to electrical issues im lost..thanks again..mike

 

[Rons beast]

Hey Mike,

I should have started with what year your Bronco was.

If it is a 95 there is no relay but every thing runs through the multi function switch that acts as a relay.  (Not my idea of ideal...but it saves Ford a bunch of money.) 

Please fill in the info on you truck in your profile for future reference.

Good Luck

 

[miesk5]

yo DD,

Wiring Diagram on a 95 by Ford via http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=46703

Grounds;

Location in Engine Bay Diagram : G100 LH front of engine compartment on upper radiator support-in front of WS washer/Coolant overflow tank;

by Seattle Bronco

G101 front of fender apron-between starter relay & headlight - Next to Batteryby Seattle Bronco



Could also be the circuit breaker inside the headlight switch cycling because the circuit is drawing too much current. Do you have extra lights added to the headlight circuit? Put an ammeter inline from the headlight switch connector to see how much is flowing. If it's normal (~10A for both low beams), replace the switch. If it's high, find the drain.

Worse case is; 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 headlight switch in Ford vehicles. The light switch involved is a Model SW-2103. These are the pull out type headlight switches usually located in the lower left corner of the front dash of Ford vehicles. The headlight portion of the switch has two pullout positions, the first for parking lights only, and fully out for headlights 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..." Miesk5 NOTE: No Bronco Listed, but this may be the result of typos or incomplete research by the company.

Source: by waltersforensic.com http://web.archive.org/web/20091111204533/http://www.waltersforensic.com/articles/fire_investigation/vol6-no3.htm

Switch **** Removal w/pic in 92-96; "...insert hooked tool into **** slot to depress spring, then pull off shaft..."

Source: by Ford via Steve @ http://www.supermotors.net/registry/media/831436

 

[devildog95]

thanks for that info miesk 5 and ron .....im going to look into this tomorrow another thing I been noticing is my volt gauge is jumping with or without the headlights  on .it will be in charging about 13.5 then drop to 8 .it can stay at 8 for a while then jump up to 10 .then all of  a sudden it will be at 13  for a while  but it never goes into the red zone. I also noticed today that if I bang the top of the dash where the volt  gauge is  it may jump to 13' the volt gauge also seems to go back to 13  sometimes if  I use the electric windows .im so sorry for all this confusing stuff but this is just different things that been .happening since the headlight issue.by the way ron it is  a 95 .with a 5.8.thanks again for all your help

 

[devildog95]

ok guys this is whats happening.i replaced the headlight switch cleaned the grounds on the passenger fender turned the headlights on I noticed the passenger headlight was  dim(.last week it was the drivers headlight that was dim) then it got bright again. so I played with the passenger side wires that come out of the headlight bulb socket and the truck stalled . the truck started right back up again  and the dim light was bright again  but every time I move those wires behind the headlight it stalls .then I shut the hood to see if the lights blink and they didn't blink . this was a noticeable problem when I started having issues with my lights . im really lost in what too do now....thanks again ...mike

 

[Rons beast]

Hey Mike,

There is no reason that the wiring to the headlights should effect the running of the engine.   I believe either there is a wiring problem far down the line where a wire or wires are shorted....OR... moving the wires by the passenger headlight is also moving the battery and breaking the (-)  or (+) connection.

Check that the terminals are both clean and tight.

The wires to both headlights are connected on one circuit. If one wire is shorted it should effect both.  I have found the connectors to headlight to be corroded and cause some problems but never to the engine.

Good Luck   

 

[devildog95]

just wanted to thank you both for all your help.. the headlights stopped blinking and are bright as the day I took the truck off the showroom floor.so it was either the switch or the ground.the truck is running fine but like I said when I move the bundle of 3 wires that come out of  the right headlight socket the truck stalls.when I get some time im going to trace the wires and see if theirs one or two wires where the insulation may have worn thin and is causing this shut down problem.thanks mike

 

[miesk5]

yo DD,

See this harness section in 96 Bronco-F-Series Workshop Manual (PARTIAL)

Same as most earlier years exc. for OBD II in 96, 4WABS (93-96); ABS (87-92); Air Bag (94-96); 3 ***** Automatic Locking Hubs (Built from May 95 through 96); Spark Plug Wire Routing & Firing Order (The firing order for 1987-1993 5.0Ls is 1-5-4-2-6-3-7-8. The firing order for 1994- 96 5.0Ls & all 5.8Ls is 1-3-7-2-6-5-4-8.);

2-piece Spindle Rolling Diaphragm Seal (RDS) used on 5/95 to 96 Broncos & F Series 1/2-ton 4WD

and a few other items that I still need to research

FIRST SUSPECT area IS HEADlight passage through Radiator core support.

Section 18-01: Wiring and Circuit Protection

REMOVAL AND INSTALLATION

http://www.diesel-dave.com/vehic/manual/stj/stji1015.htm

Fender Apron, Right, Gasoline Engines

#3 — To RH Headlamp

PART of 12A581 Wire Assy.

Look for more depictions of 12A581

Not detailed though;; so check the Electrical Schematics, Headlamps

http://www.diesel-dave.com/vehic/manual/stj/stjh1016.htm

Red/ Black wire is a usual suspect

or

Light Green

 

[devildog95]

thanks miesk 5 for this info ...I guess if something was rubbing against my body for 20 years and 171000 miles later I would be shorting out too........lol..by the way I really liked your post reply to the wedding rental .hope some can help them