MrLeadFoot

This thread includes a mod to keep your low beams on when your high beams are turned on, as well as a mod to that mod.

Here's the info on the first mod, which works great in keeping your low beams on when your high beams are turned on:

Radio Shack Automotive Relay Part #275-226 ($6.99)

Locate harness connector plug for headlights/motor on passenger side up front near the headlight and disconnect it. (You can do this on either side of the car, but passenger side is closest to fusebox and battery compartment.)

Run #12 AWG wire from fusebox power terminal to relay location and connect to pin 87 on relay. I mounted my relay to the battery compartment separator on the battery side.

Tap into high-beam (green) wire on the main harness side of the connector and connect to pin 86 on relay.

Tap into low-beam wire (brown) and connect to pin 30 on relay.

Tap into ground wire (black) and connect to pin 85. I actually ran a separate wire to a chassis ground bolt.

Connect #12 AWG wire you attached to pin 87 to +12V power. I ran mine to the large nut on the fusebox with the two red cables. I added an inline fuse, too.

Done, now, go blind people with 4 lights. Just kidding.

Here's a diagram of the setup described above. Note that the pins may not be oriented in the right place in the diagram, but the pin numbers are indeed correct:


This mod results in a small change to the stock flash-to-pass feature, which won't affect many people. In fact, if you don't use the flash-to-pass feature in the daytime, you won't even notice the change, so you're good to go right here, and don't even need to read any further.

Normally, when using the flash-to-pass feature during the day when your headlights are OFF, the fog lights flash. The high beams also flash, but since the headlights aren't up when your lights are off, you don't notice them flashing.

Now, with the mod described above, the headlights DO pop up when you flash-to-pass with your headlights OFF. Why? Because the headlight doors pop up whenever power is supplied to the low beams, and since this mod supplies power to the low beams whenever the high beams are activated, when the high beams receive power from the stock flash-to-pass function, the headlights pop up.

As I previously mentioned, if you don't use the flash-to-pass feature during the daytime, you won't notice anything different in this area, so this mod will do what you want just the way it is by keeping your low beams on when your brights are turned on.

However, I use my flash-to-pass in the day, and I don't want the headlight doors popping up when I flash-to-pass during the day, so I've come up with a 2nd mod that prevents the lights from popping up when flashing-to-pass during the day.

What we need to do is supply power to the relay we installed in the diagram above only when the lights are turned on. That way, when the lights are off, the stock configuration is in place and flash-to-pass does not raise the headlights. But, whenever you turn on your lights, the side effect of this mod raising your headlights becomes moot because with or without this mod, your lights pop up whenever you turn on the lights, so the relay end up just doing it's originally intended job, which is to power the low beams when your brights are turned on.

The below diagram shows a mod to the mod above, in which a second relay is used to supply power to the first relay ONLY WHEN THE LIGHTS ARE ON:



Notice that the diagram above uses the side marker/running/parking lights to trigger the second relay to supply the power to the first relay. That's because the side marker lights receive power only when you turn on your lights, thus when the second relay sees the side marker lights go on, it then sends power to energize the first relay.

Using the side marker lights as the trigger for the 2nd relay virtually eliminates the issue of your headlights popping up when you flash-to-pass when your lights are off. The ONLY time your headlights will pop-up when you flash-to-pass during the day is IF you drive with ONLY your running lights on (with or without your fog lights). But, then again, you would typically only drive with ONLY your running lights on (if you do so at all) for a very short period during the dusk hours, and even then, how often would you flash-to-pass within that hour?

If you have any questions or comments, I'm all ears.

EDIT: At the suggestion of another member this modified diagram was added to this post. In fact, I am currently running this particular setup and it works great:

MrLeadFoot

Edited for clarity

screw991le

Nice write up.

Jims2001

Unbelievable timing of this thread. Just looking into doing this to my Vette and my Van. Looks like it will work on both. How about a mod where the fog/driving lights stay on with the high beams!

unionlandlord

Thanks, grate info.



Paul G.

Zilla

i had done this one my 89 Z24 back in '91 and it was awesome on how much light was put out and how much you could see.

I also did the mod to have high beam bulb in the low beam sockets.

MrLeadFoot

You could do the same thing for the fog lights. Use a relay, just like the first schematic shows, but instead of connecting pin 30 to the low beam power, connect pin 30 to the power wire of the fog lights, which on my '01 coupe is the purple wire.

MrLeadFoot

I also, up until two days ago, had high beam bulbs in the low beam sockets. But I recently got the HID low beams, and WOW, the HID lows alone put the lows-in-the-highs sockets to shame! In fact, when I turn on my brights now, because the low beams stay on, I can barely even tell the highs were turned on. So, next week I'm going to add HID high beams. This mod will REALLY come in handy then, because HIDs take a few seconds to reach full power, so keeping the low beams on while the highs power up will prevent me from a momentary lag in lighting, which is extremely important, because the whole reason you even turn on your highs is because you need more light at that moment, and dropping lighting power for even a few seconds at a moment like that can mean the difference between life and death.

0TheRadioFlyer97

for clarity and the diagrams I was to lazy to draw.

mcgilles

nice write up! I use my running lights 24/7 because I like to be seen, and I like the way they look

one modification you might want to think about making though:
the way you have your two relays setup you will be running your low beam power through both of them when you have your hi/lo feature on. fewer connections make for fewer places where things can go wrong. it might be a better idea to run the power for the hi/lo only through one relay, and use the contact of your extra relay to turn on and off the high beam signal to the trigger of the hi/lo relay. so take your high beam signal and run it to 87 on your new relay, then out from 30 and into 86 on your hi/lo relay. You could use a lower current capable (and thus cheaper) relay for the new one since in this case it will only be passing the coil current of the hi/lo relay (60mA for some of them, almost nothing). it might also make the setup more reliable, but it will work either way.

nice work!

Vetteman Jack

Great write-up. Thanks for all the info.

MrLeadFoot

But isn't that what the Daytime Running Lights are for? In any case, if you prefer using your running lights 24/7, then Mod 2 won't help you. And, that means your contribution is coming directly from your passion to help your brethren on this forum. I, for one, appreciate your extra effort here, and salute you for taking the time to make your valuable contribution!

While at first glance your suggestion sounds more complicated, I think it merits clarification because if I understand it correctly, it reduces the amount of current that flows through both relays, which is a benefit to all of us interested in this mod:

In my second diagram above, relay 2 regulates 12 volt power supplied to relay 1 in a manner that routes that 12 volt power power through both relays.

What you propose instead is to use relay 2 to regulate the high beam signal supplied to relay 1, as depicted in the diagram below.



In other words, when the side marker signal triggers relay 2, rather than allowing 12 volt power to come through both relays, relay 2 would instead allow the high beam signal to trigger relay 1 , which in turn would allow relay 1 to let 12 volt power through. Then, when the high beams are turned on, only relay 1 needs to supply the 12 volt power to the low beams, exactly the same way as depicted in diagram 1 at the top of this thread. So, the difference between your suggestion and my setup in diagram 2 is that 12 volt power would only need to run through relay 1, instead of both relays as depicted in diagram 2, correct?

Also, do you happen to know if there's a side marker power wire that can be tapped up near the fusebox, after the fuse, instead of having to tap the wire in the area down below the headlight? It sure would make it easier than reaching down in that bumper recess, you know what I mean?

mcgilles

looks like you've got it!

what I do is sort of like DRLs, but I hate DRLs with a passion! the difference is I want all of my lights on except for the headlights, I want the sidemarkers and tail lights also, which the factory DRLs don't turn on. so I have disabled my DRLs by doing the relay mod, and I flip the parking lights on every time I get in the car. I want to make the DRLs work my way, I'm working on that one. the change would be, when the lights are OFF the DRLs are OFF, when any light (running lights, headlights, whatever) are ON the DRLs would turn ON. this is the opposite behavior for the factory DRL lights, which are on when all the other lights are off, but turn off when you turn on your regular lights...I think I've found a way to do it, more details on that later.

as for your side marker lights, according to the service manual the power which goes to the front side markers is the same wire which goes to the parking lights, its a brown wires which runs to all 4 bulbs up front. that wire does come through the underhood electrical center, but it is fused in the instrument panel electrical center. according to the manual there is a splice pack for that wire in the underhood electrical center (one wire comes in to the center, and 5 go out, 4 of them go to the two side markers, and two go to the parking lights. the 5th goes off the page and looks like it hooks up to something else. Since there is no fuse or anything with a location attached to it where you know which wire it is though, it may be difficult to find. with the number of wires in that center its likely that there are more than just these 6 brown ones. just check and double check before tapping into any of them!

MrLeadFoot

OK, I just got back from getting another relay, and I'm going to install it today. I think I might have to tap the connection near the side marke/running lights themselves if the power wires to them at the underhood fuse center have no connectors I can separate to test, you know what I mean? We'll see. I'll post back up here in a bit when I'm done.

MrLeadFoot

OK, lifted the underhood fuse center, and all I can say is !

It was much easier to just tap into the side marker light down in front. Piece of cake install, and now I have all 4 lights on when I use the high beams, as well as still have my stock flash-to-pass feature which does NOT raise the headlights when I flash-to-pass with the lights off.

HID high beams, here I come!

jrprich

So to get all the lights on at once, Fogs, Low, and High do we just use

The Alt to Mod 2 diagram ?

oneshot

Could you do the same thing with diodes. I have a 04 tahoe and they had a write up on how to get the fogs/DRL/low/High on using diodes at the fuse box....any one hear of this on our cars.

jacks996

thanks for the write up

MrLeadFoot

Mod 2 and Alternate to Mod 2 provide the same results. When your headlight stalk switch is turned on, and you turn on your brights, both methods provide power to the low beams so that the low beams are on when the high beams are turned on.

I used the Alternate to Mod 2 diagram, which works great.

Note, however, that the fogs are not part of the equation in either of the three diagrams.

Although there are a couple of different options to keep the fogs on, too, I just don't see the point of that if you have your lows on with your brights. You wouldn't need the fogs on then, because those 4 lights would drown out the fogs. Consider as well that the whole reason you would want lows on with highs is so that you can see down the road as best as you can, and fogs are just not going to help in that regard (seeing down the road), even if you had HID fog lights.

old stingray

Thanks for the write-up.