i know this has been talked about i just can't find what i am looking for, i basically want to put hids in my truck, its a canadian truck so i have to by law have the drls. i know you can disable them by removing the relay or unplugging the resistor, i just want the drls to function at full 12v instead of the dropped voltage, would unplugging the resistor and essentially shorting the terminals give the drls full voltage? any help would be awesome, i also plan on putting hids in my fogs so moving the drls there isn't an option for me

 

Forgive me if I ask stupid questions, I do that all the time, but it's because I really do try to understand.

I'm guessing, since you want to put HIDs in your fogs, you never see fog where you live? If you do have fog, I would think HIDs would be deadly, and make your truck undrivable in the glare at night.

Generally, you want DRLs to operate at reduced voltage for two reasons: longer bulb life (which may not be a factor in a plasma arc bulb) and, a smaller hit on fuel economy (the energy to light those bulbs has to come from somewhere - it's not free). Now I know there are HIDs on the market that use even less energy than filament bulbs, but still, wouldn't you opt for a reduced energy demand if you could get it?

You really don't need much light for a functioning DRL. It's not lighting anything. It just has to be visible to oncoming traffic, so the idiots there won't mistake you for a dark spot in the road.

To answer your question though, I would think shorting the resister would do what you are saying. SSCULLY would be a better information source though.

- Jack

 

you have the correct plan.

When you unplug the DRL resistor, there should be 2 pins in the connector, and the 2 wires to the DRL resistor should be :

Red w/ Black stripe
Orange w/ light green stripe

Instead of the power to the headlamps ( with the main headlamp switch in the off position ) being reduced by the resistor, you will have full + voltage.

you can use a scotch lock or T-tap splice on the wire harness, just after the connector towards the factory harness to do this or go to a bone yard, and get a DRL resistor off a wrecked truck, cut it apart and remove the resistor, and solder in the jumper, and install this on your truck.
Both methods work, just remember if you do the splice on the truck's wiring, blind end tape the connector where the DRL resistor was at.

 

Back to the conversation from the other day, trigger voltage on the HID ballast.

If the trigger voltage is high enough, a DRL resistor might cause it to a) not ignite, leaving the lamps off or b) cause the HIDs to flicker ( clipping on the trigger voltage ).

If the HID kit has a low enough trigger voltage, this is a non issue, but I have yet to see a kit that has a low trigger voltage on it.

The other option is to get a relay that has a 6 V coil, and use this to trigger the HID ballasts, but now you are building a mouse trap for no reason.

Stay away from my dumb question of the day, that is reserved for me ONLY

 

thanks for the posts, i will try the short idea later, as far as drls i do want them. but my truck doesn't see much driving, max 6000 miles a year, used to see closer to 20000 but now i have a company van so thats all changed, i can see your point about fogs being too bright but for the amount i see fog here and the odds of me being in my truck at the time of fog, is pretty rare.

 

Naw, Steve! You do not get control of the dumb question field! We HAVE to share.

But, you did clarify something that I suspected, but was too lazy to look up, that low voltage could cause the bulbs to flicker or not burn at all.

I suppose it takes a high voltage to "strike the arc", but then lower voltage to maintain it?

I've been reading about "dimmable" HIDs (the article is about typical metal halide or high pressure sodium AC powered lamps, but I'm sure the principles are similar) and it looks like the technology has been around a long time as both an energy saving measure and as a startup time "reducer". Seems logical to me this feature could easily be incorporated into HID DRLs.

I wonder though, if the increased number of on-off cycles, caused by lights on during daylight driving, would greatly reduce bulb life? That would be a killer if it's the case.

- Jack

 

I can have control of the dumb questions, I'm a mod now and I can delete every dumb question you have so I corner the market on them

the low voltage would be one of 2 things.

1. If the ballast plugs directly into the headlamp harness ( trigger and power from the factory bulb connector ) this could be a case of the ballast may fire, but cannot hold the required wattage to keep the bulb running. One of the SV here say not to use them with DRL ( don't know why they don't have the DRL required installs do what jayjma20 asked. Easy enough to fix it ).

2. For the kits that use a trigger lead ( to the factory bulb connector ) and a separate power input to the ballast, this might be a case of the trigger voltage is 10.2 and greater, and you might see this when running at higher RPMS ( when the alternator output is close to ~14.1 V ) but at idle / lower RPMs, the voltage drop over the DRL resistor is enough to fall below 10.2 DC, and the trigger input is now considered off, ballast shuts off.

If the install required DRLs and the headlamps were converted to HID, the easy thing is to leave the fogs as std / SilverStar bulbs, and clip the of the DRL resistor and rewire to the Fog lamps.

This would remove the continual run of the HIDs, and put the consumable operation on a cheaper bulb. I would imagine that this would increase the capsule life span, as well as the ballast life span. They do go out over time. The cut sheet would show the calculated life span of the setup, and using them as DRLs would count towards this amount.

That is just my thought on the topic, not like I am going to be installing HIDs any time soon. I am running SilverStar bulbs in the headlamps, fogs, and in the Hella grille. I have more then enough usable light output with that setup.

 

Figures! Give a guy a little power and it goes right to his head! Where have all the people with integrity gone to? (Or was that just a dumb question)?

- Jack

 

Got me, anyone see any