Community Forums

mrboyer · 10-21-2019, 05:43 PM

Is there a dimmer in the switch by twisting the knob? If there is one, there is a coil of Nichrome resistance wire that gets very hot when turned to full dim. If you turn the knob the other direction, does the heat get less?

aden · 10-21-2019, 05:58 PM

Quote:

Originally Posted by mrboyer

Is there a dimmer in the switch by twisting the knob? If there is one, there is a coil of Nichrome resistance wire that gets very hot when turned to full dim. If you turn the knob the other direction, does the heat get less?

I’ll check

aden · 10-21-2019, 06:00 PM

Quote:

Originally Posted by A Traveler

The switch is getting hot. The SWITCH is bad. It has developed a high-resistance connection within the switch. That bad connection generates heat when current passes through it.
Installing LED headlights will fix the problem...for a while. They always (not “generally”) draw less current than an incandescent lamp. Less current = less heat. But you would be treating the symptom, not the disease.

It’s not a relay.
It’s not a ground.
It’s the switch.

I replaced the switch last year and replaced the ground and now it’s doing the same thing and it’s only the headlight terminal.

Unplanned Tourist · 10-21-2019, 06:31 PM

I would suggest that you install relays as close to the headlights as possible.
Run a good heavy (8-10 gauge) wire to the power supply to the relays.
That will do 3 things.
#1 it will dramatically drop the amperage going through your headlight switch.
#2 it will supply a full voltage to your headlights (brighter lights)

#3 it will make your switch last forever!

Happy Glamping.

aden · 10-21-2019, 06:59 PM

Quote:

Originally Posted by Unplanned

I would suggest that you install relays as close to the headlights as possible.

Run a good heavy (8-10 gauge) wire to the power supply to the relays.

That will do 3 things.

#1 it will dramatically drop the amperage going through your headlight switch.

#2 it will supply a full voltage to your headlights (brighter lights)

#3 it will make your switch last forever!

Happy Glamping.

Thanks

Dav L · 10-21-2019, 07:48 PM

Quote:

Originally Posted by A Traveler

The switch is getting hot. The SWITCH is bad. It has developed a high-resistance connection within the switch. That bad connection generates heat when current passes through it.
Installing LED headlights will fix the problem...for a while. They always (not “generally”) draw less current than an incandescent lamp. Less current = less heat. But you would be treating the symptom, not the disease.

It’s not a relay.
It’s not a ground.
It’s the switch.

Most LED headlights use the same amperage as the incandescent they typically replace. But they put out more light at the same amperage. So, I don't agree. One HAS to generalize because there is a zillion different LED bulbs one can buy all with different ratings.

And how do you know it's not a relay or a ground? At this point, unless you know the circuit of the particular RV...we don't even know if there IS a relay or not. Or that the ground that got cleaned up even has anything to do with the headlight circuit.

You MAY also be correct that the switch has high internal resistance. But that's just a guess at this point. Note that the OP states that the switch was replace last year. Two switches back to back with the same issue? Only if something else is causing them to fail (bad ground etc.)

Unplanned's proposal is a standard way to avoid this problem and typical with a decent headlight upgrade. But, most modern vehicles a relay already drives the headlights, not the switch in the cockpit. All is a guess until we know the circuit.
A voltage drop test with headlights on is helpful to know if there is a high resistance connection to the battery.

Could be as simple as the connector on the switch is loose / corroded.

The prime reason this has been a recurring problem is it was never diagnosed correctly. And step 1 is symptom gathering, step 2 is schematic so you know what you are dealing with. Gunshotting parts replacements can mask the problem ("I know it's not the switch because I replaced it...")

If you are going to DIY electrical problems on your rig, you should be finding the schematic for it and keep it handy. Or you are going to be spending a LOT of time and money guessing. Put your RV year / make / model in your signature. That might help someone else help you.

153stars · 10-21-2019, 07:51 PM

You can find a lot of info on headlight relay mod not just for RVs including some kits and detailed directions to make it easier. Google it HL relay mod. And search on here.
A lot of people are happy with LED HLs as well .don't go real cheap or universal they many times don't hit/focus on reflector right. Read reviews.

aden · 10-21-2019, 08:39 PM

Quote:

Originally Posted by Dav L

Most LED headlights use the same amperage as the incandescent they typically replace. But they put out more light at the same amperage. So, I don't agree. One HAS to generalize because there is a zillion different LED bulbs one can buy all with different ratings.

And how do you know it's not a relay or a ground? At this point, unless you know the circuit of the particular RV...we don't even know if there IS a relay or not. Or that the ground that got cleaned up even has anything to do with the headlight circuit.

You MAY also be correct that the switch has high internal resistance. But that's just a guess at this point. Note that the OP states that the switch was replace last year. Two switches back to back with the same issue? Only if something else is causing them to fail (bad ground etc.)

Unplanned's proposal is a standard way to avoid this problem and typical with a decent headlight upgrade. But, most modern vehicles a relay already drives the headlights, not the switch in the cockpit. All is a guess until we know the circuit.
A voltage drop test with headlights on is helpful to know if there is a high resistance connection to the battery.

Could be as simple as the connector on the switch is loose / corroded.

The prime reason this has been a recurring problem is it was never diagnosed correctly. And step 1 is symptom gathering, step 2 is schematic so you know what you are dealing with. Gunshotting parts replacements can mask the problem ("I know it's not the switch because I replaced it...")

If you are going to DIY electrical problems on your rig, you should be finding the schematic for it and keep it handy. Or you are going to be spending a LOT of time and money guessing. Put your RV year / make / model in your signature. That might help someone else help you.

1997 dutchstar dp model 3456

Dav L · 10-21-2019, 08:48 PM

when you locate the schematic, I can further assist.
But that might take some effort. I never found my exact one, but I have one a couple years newer and so far mine is wired similarly so it has been very useful.

My 2002 Newmar uses relays. Has got NOTHING to do with the "switch".

Roy1 · 10-21-2019, 10:42 PM

Generally if the switch is hot to the touch it needs to be replaced with a new switch. The excessive heat is caused by a poor connection inside the switch which will give low voltage to the headlights these switches don’t cost a lot of money. If it were mine i’d Replace it.