Headlight switch drains lights
Thread Starter
|
Junior User
Joined: Jul 2006
Posts: 50
Likes: 0
From: carleton, MI
Headlight switch drains lights
Here is another good one. I have all grounds, and cables hooked up, battery fully charged.But when I turn the headlights on the headlight switch makes a click noise, sound like a turn signal relay, the lights come on, and after awhile it starts shuting the lights off and on, even the cab light. I think I have a bad light switch??? Causing a electrical drain..... what do ya think.
Senior User
Joined: Mar 2007
Posts: 224
Likes: 0
From: San Jose , ca
The headlight relay is intergal with the switch, and is cycling. Replace the switch,and the relay will be part of it, then the lights will stay on. I had exactly that problem one night on a narrrow road towing trailer. Scary!
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
There is no relay in the switch, it is a thermal circuit breaker. Either the switch assy is bad or the headlights draw too much power.
The headlights can draw too much power caused by a short in the wiring or both high and low beams on at the same time due to a short in the wiring or a shorted/bad dimmer switch.
The headlight switch assemblies do get old and the thermal breaker gets weak either due to oxidation, corrosion, poor contact, or an accumulation of insulating dust.
The headlights can draw too much power caused by a short in the wiring or both high and low beams on at the same time due to a short in the wiring or a shorted/bad dimmer switch.
The headlight switch assemblies do get old and the thermal breaker gets weak either due to oxidation, corrosion, poor contact, or an accumulation of insulating dust.
Fleet Mechanic
Joined: Sep 2003
Posts: 1,279
Likes: 0
From: savannah,ga
more often than not it is the dimmer switch
pull back your floor covering and check the connector
these usually are burnt or corroded
if not there the 2nd place to look is
the headlite switch connector
they like to overheat and get crispy too
pull back your floor covering and check the connector
these usually are burnt or corroded
if not there the 2nd place to look is
the headlite switch connector
they like to overheat and get crispy too
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Usually the dimmer causes the flickering without causing the circuit breaker to trip.
It is from getting a partial ground because of corrosion.
To 66f25,
We often suggest to people to convert to a relay system (like Volvo) because of the inferior Circuit breaker system thru the switch.
It is from getting a partial ground because of corrosion.
To 66f25,
We often suggest to people to convert to a relay system (like Volvo) because of the inferior Circuit breaker system thru the switch.
Trending Topics
Senior User
Joined: Oct 2006
Posts: 194
Likes: 0
my lights dim in and out when idling? same issue?
( recently cleand most grounds and paintted over them. Rebiult Alt. ,new bat.,Voltage reg., ignition mod.)
( recently cleand most grounds and paintted over them. Rebiult Alt. ,new bat.,Voltage reg., ignition mod.)
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
Originally Posted by Ranger73
my lights dim in and out when idling? same issue?
( recently cleand most grounds and paintted over them. Rebiult Alt. ,new bat.,Voltage reg., ignition mod.)
( recently cleand most grounds and paintted over them. Rebiult Alt. ,new bat.,Voltage reg., ignition mod.)
Thread Starter
|
Junior User
Joined: Jul 2006
Posts: 50
Likes: 0
From: carleton, MI
Installed new switchs, floor and headlight, also attached the ground strap to the motor, and fixed the loose connection on the headlight, and reattached the ground on the regulator, and I drank another beer, and the problem went away. HOLY S@#T.
Thanks again.
Thanks again.
