Hot Headlight switch

[Great White]

Howdy folks! Newbie signing on!
How hot does your headlight switch get after 1 hour or more of driving? Mine hits 150f!
I went to Crown "Dodge" our "Five Star Dealer"in Ventura and they said "Load is normal, temp is normal" Today I placed a temperture tattletail on the dash and drove the truck to work and back. Stopped at the dealership and had the service writer "put your finger right there!" Suprise, he pulled his finger back rather rapidly. Now they want my truck for a day to "Investigate the Problem" This is where I become concerned that the ******** may begin..... un-asked for re-flashes, training dummy(victim), scratches ect. HELP

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2001. 5 2500 ETH/DEE 4x4,Patriot Blue over Silver,Camper pkg, Trailer pkg,Agate Leather,Stainless Smitty Bars,Tow hooks... . Except snowplow!

 

[HC]

They all get VERY hot, IF you use your dash light dimmer control. If you leave it on the brightest setting, then it should not get hot. Basically, the dimmer is just a variable resister, so the more resistance you dial in, the dimmer your dash lights get but the hotter the switch gets. If you can wait a day or two, I'll check temps and post some numbers.

 

[Big-D]

Great White,

The problem you are refering to is common with our newer trucks. If you do a search on this topic you will find lots of responses to this very issue. The fact remains, heat is caused by the resistance of voltage to dim your instrument cluster. Try leaving the dash lights on full brightness and then feel the temperature of the switch. Big difference.

I have continued to use the dimmer portion of the switch as I so desire without concern to heat. I have never smelled anything burning and thus far (2yrs) nothing has failed. That will probably happen now after this post. Ha! Dave

 

[Vaughn MacKenzie]

There is a very large heat sink on the back side of the light switch assembly to dissipate the heat from the resistor.

 

[The patriot]

Maybe one of you guys will BOMB the switch.
Put a small computer fan on it. #ad
#ad

Eric

 

[Great White]

Well thanks for the input I guess some BOMBING is required. I will figure out how to slave a solid state voltage regulator and LED's for panel lamps to reduce the draw on the dimmer!
If I come up with a definitive fix I will post it!

???? How do yor remove the front panel from the dash, just pull hard? any tips? anyone removed your dash panel?
Thanks, Rich

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2001. 5 2500 ETH/DEE 4x4,Patriot Blue over Silver,Camper pkg, Trailer pkg,Agate Leather,Stainless Smitty Bars,Tow hooks... . Except snowplow!

 

[HC]

OK, I measured the temps after a one hour drive during which I had the dimmer set to it's lowest setting. Several spots were above 150 degrees, and I found one that peaked at over 170 degrees.

Question: Can others dim the lights until the dash lights turn out entirely? (I can get them pretty dim, but they don't go all the way out. )

 

[Vaughn MacKenzie]

Great White, it is easy to remove the instrument panel bexel. . . just pull on it and it will snap off. Then the headlight switch can be easily removed with 3 screws. I got into mine to tap into the wiring for my gauges.

My they don't make a solid state unit to begin with is beyond me, using a pot and resistor is as old as the birds.

Vaughn

 

[Great White]

Vaughn, I fix stuff like this for a living, just need to do the homework.
1. Determine voltage range we like.
2. add additional resistor to existing dimmer to reduce current to acceptable levels.
3. select voltage regulator and bias so input gain delivers desired voltage with sufficient ampacity to deal with load without heating effects... why waste the power as heat?

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2001. 5 2500 ETH/DEE 4x4,Patriot Blue over Silver,Camper pkg, Trailer pkg,Agate Leather,Stainless Smitty Bars,Tow hooks... . Except snowplow!

 

[adiabatic]

Unfortunately no linear regulator will solve this problem- you end up with heat whether you use a resistor or transistor. The correct solution as Vaughn hinted is to use a switching regulator. If done right the heat dissipated will be negligible. Other makers figured this out at least 15 years ago. Blame the DC bean-counters.

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1997 4x4 CC 5spd, 230hp kit, Horton fan, Sport headlamps, Optima RedTops, 98 shift levers and console, RS5000 shocks, Yaesu VHF radio, and BCT7 scanner in the overhead console... N7DAL.

 

[GeoVeo]

Great White, I don't know about your 2001, but as I remember, to remove the dash panel on my '94 I also needed to remove two screws holding the ash tray in.

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'94 2500 Driftwood, Auto 4X4, 4. 10

 

[John Berger]

My headlight switch gets very hot as well. The dash panel just pulls off on mine.

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1999 Dodge Ram 3500 Quad Cab 5 spd; 4:10 LSD rear; Mag-Hytec diff. cover; US Gear EGT and Boost gauges. Amsoil foam air filter and synthetics from nose to tail.
Cummins Power, don't leave home without it