All lights cutting out!!! Please Help!
Thread Starter
|
Freshman User
Joined: May 2005
Posts: 34
Likes: 0
From: long island
All lights cutting out!!! Please Help!
Ok the other day was the 3rd time this has happened to my 93 bronco eddie bauer 5.0. Im driving down the parkway at night and all the sudden, the lights go out completely, including the interior lighting. They come back on a few seconds later, but continue to flicker. So far, all 3 times occured after the truck had been running for at least 30 minutes at highway speeds. Has anybody encountered this problem before, and if so, where do I start?
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
Um, the solution is to replace the main light switch (headlamp switch) because the circuit breaker has lost it's ability to sustain the load that it should be able to handle. All electrical components are susceptible to this kind of failure as they age. You might also want to meter the headlamp circuit for resistance (ohms) to make certain you don't have an increase in resistance and thereby additional heat generation due to weak connections. Standard 55watt headlamps should produce a reading of 1.3-2 ohms approximately when metering both lamps in parallel. This number may be a touch higher depending upon where in the harness you take the reading. Grounding connections are the most susceptible in this case. Increased heat causes a weakening of the circuit breaker as well. Adding relays requires adding additional fuses or circuit breakers and only bypasses the real problem. If the original headlamp switch C.B. was able to handle the circuit up until recently and you haven't added any significant load to the headlamp and/or parking lamp circuit (i.e. higher wattage lamps) then the internal breaker in the switch should be able to handle the load just as it always has.
Posting Guru
Joined: Apr 2005
Posts: 2,018
Likes: 0
From: Longview, TX
Interesting greystreak92. I drove 1,100 miles last week and by chance noticed the dash above the headlight switch stays warm when the lights are on for a long time. Is that normal? Could my switch be failing or is it just heat from the dimmer? No trailer nor extra lights, all original.
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
The dimmer will always disburse heat especially if you run with your dashboard lighting below full intensity. The electricity that is being bled off to keep the lamps dimmer manifests itself as heat energy. If you are concerned that there could be a problem, I suggest pulling the switch and making certain the connections are tight and inspect the coil and brush that make up the dimmer for wear or signs of arcing. If there is no significant discoloration, wear, or loose connection, let it be until or unless you run into a problem like fredford55 is dealing with.
Fleet Mechanic
Joined: Aug 2002
Posts: 1,568
Likes: 33
From: Swansea SC
All this usually happens in winter adding your vehicles heater temperature ( heat wide open)to make it worst. I have encountered this several times in all of my older vehicles. Culprit was the HEADLIGHT SWITCH . T
R
R
Trending Topics
Junior User
Joined: Sep 2005
Posts: 95
Likes: 0
Do you have any auxillary lights hooked into headlight circuit? If so,then those lights have to be on a relay.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Fords to Drive Before You Die
Joe Kucinski
3 Best / Worst Features Of The 2025+ Ford Expedition
Brett Foote
10 Ways Ford is LOSING to the Competition
Joe Kucinski
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
New User
Joined: Feb 2009
Posts: 24
Likes: 0
Read this...
https://www.ford-trucks.com/article/...r_Brights.html
Don't know why it claims to be posted in '04, because Steve (the author) had it on his website
in '97...
Steve & the Rockette
'63 F100 4.8L V8
'68 F100 6.4L V8
'72 Capri 2L
'73 Capri 2.6L V6
'73 Capri 5.0L V8
'73 MG B GT 2.6L V6(Ford)
2 '76 Capris, 2.8L V6s
'78 Bronco 7.5L V8
'86 F150 5.0L V8
2 '87 XR4Tis 2.3L Turbo
'01 ZX2 2.0L DOHC
'08 Subaru Imprezza 2.5L DOHC Boxer
https://www.ford-trucks.com/article/...r_Brights.html
Don't know why it claims to be posted in '04, because Steve (the author) had it on his website
in '97...
Steve & the Rockette
'63 F100 4.8L V8
'68 F100 6.4L V8
'72 Capri 2L
'73 Capri 2.6L V6
'73 Capri 5.0L V8
'73 MG B GT 2.6L V6(Ford)
2 '76 Capris, 2.8L V6s
'78 Bronco 7.5L V8
'86 F150 5.0L V8
2 '87 XR4Tis 2.3L Turbo
'01 ZX2 2.0L DOHC
'08 Subaru Imprezza 2.5L DOHC Boxer
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
...AND a separate fuse that can handle the combined amperage of any additional lamps on the circuit. This fuse cannot be inline with the relay "trigger circuit" (which would be the circuit from the headlamp switch) but rather must feed from an independent power source i.e. directly from the battery or the battery side of the fuse block.
Posting Guru
Joined: Apr 2005
Posts: 2,018
Likes: 0
From: Longview, TX
Heavy-duty headlight wiring harness
After studying https://www.ford-trucks.com/article/...r_Brights.html
I decided my connections may not be as reliable as I would like them to be so passed I on this project.
However, LMC shows three Heavy-duty headlight wiring harnesses according to the year. New lamp sockets, two relays, connect to OEM connector and run separate wire to battery which I assume is fused. See the picture in the LMC catalog under lights. Has anyone tried it? It is thirty bucks. http://www.lmctruck.com/icatalog/fd/full.aspx?Page=60
Looks like one could unplug it and go back to stock if a relay failed.
I was thnking of new original bulbs to start with unless there are better suggestions.
I decided my connections may not be as reliable as I would like them to be so passed I on this project.
However, LMC shows three Heavy-duty headlight wiring harnesses according to the year. New lamp sockets, two relays, connect to OEM connector and run separate wire to battery which I assume is fused. See the picture in the LMC catalog under lights. Has anyone tried it? It is thirty bucks. http://www.lmctruck.com/icatalog/fd/full.aspx?Page=60
Looks like one could unplug it and go back to stock if a relay failed.
I was thnking of new original bulbs to start with unless there are better suggestions.
Last edited by b4hntn; May 8, 2009 at 10:49 AM. Reason: Found LMC link
Elder User
Joined: Feb 2007
Posts: 757
Likes: 0
From: Nikiski Alaska
You can if you want . But the problem lies in that the porcelain part of the switch,with the wire that is used as a resistor to dim the lights wears out. As the switch wears and loosens the heat becomes more intense in the switch, which causes it to over heat and turn off or much worse melt. The head light switch is more than likely the problem. In my opinion its better to replace the worn switch than to try a bandaid fix. Good luck whichever way you go.
