Topic: "Driving Lights"

[Kevin]

My friend has a 77 Esprit that he cloned into a Trans Am and has installed these little rectangular driving lights in the area where the parking lamps should go. We're trying to figure out a wiring solution, and I have an idea, but the only wiring experience I have is in the stock realm (dash harness, forward lamp, engine). I was thinking running a wire from the battery to a switch in the interior then back out to the respected lamps and then just ground them to the chassis. What's the best way? I think my idea wouldn't work for some reason (don't really know what reason that is) but I'm doubtful.

I wouldn't think he'd need relays if he just ran it straight to a switch from the battery through a fuse and then back out to the lights.

Let me know guys, I'd really appreciate some help as I told him I'd do some research and try to figure out the best way.


78W72 (?) - I'm looking for you on this one man.




Thanks in advance,

Kevin

[Mongo]

All depends on the total current draw of the lamps he is using. A relay set up would be best but if the lamps dont draw too much then the switch and wire idea you have should work just fine.

[Kevin]

I think relays would be cool too, but I know nothing about the right kind to get or how to wire something like that up. My aftermarket headlights are wired up with aftermarket relays that M and H built into my forward lamp harness, but I don't know how to do it honestly.

[Kevin]

LOMILETA did something like this on his car.  It came out great too.  Hopefully he can help. 

Are you thinking of the Angel Eyes?

[brian c]

I wouldn't think he'd need relays if he just ran it straight to a switch from the battery through a fuse and then back out to the lights.

Err...wrong!

A simple lit toggle switch can't handle the power you're going to be putting to them. You NEED to use a relay. 4 pin will work fine. You can pick them up at any Radio Shack or autoparts store. I can say that if you pick it up at Radio Shack they have a diagram on the back for what pin needs to go where. I can try talking you through it here but my drawing skills are absolutely abominable so please don't ask for that

OK here goes....

Pin 30 - this is your + feed from your battery. Make sure its fused!
Pin 87 - this is your + feed to the lights.
Pin 85 - this is your GROUND connection.
Pin 86 - this is what you connect your on/off switch to.

As for your actual switch, any on/off switch will work. With a simple, non-lit, on/off switch there are only 2 connections. First is your out to Pin 86 on the relay. Second is your activating + source. Can be ignition hot OR always hot. **IF you use the latter then you need to make sure you turn the switch OFF otherwise you'll drain your battery.

A lit switch as a 3rd connection. First is out to pin 86. Second is your activating + source. Third is a ground to provide a complete circuit for the light inside the switch to light up.

IF you end up buying a 5 pin relay, just ignore pin 87a unless you want to trigger some other electrical device when you turn off the driving lights.

[Kevin]

Will this work?
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_5760055-P_x_x?cm_mmc=CSE-_-Google-_-VALUE3-_-VALUE4&ci_src=14110944&ci_sku=5760055#fragment-2

Also, he'll need two relays, one per light correct? Just like my headlight setup?

Also, once it's all wired up, can I run the two wires that go to the switch together?


I seemed to have found a diagram.   http://www.mp3car.com/vbulletin/faq-emporium/117895-faq-relays-how-they-work-how-wire-up.html

[brian c]

Kevin,

1 relay is all you need. That's how my driving lights are hooked up in the Tundra. I think I used a 30A which will be plenty unless you're running some "Baja offroad 17" gonna make the driver in the other lane blind" lights then at that point you may want a relay per light.

Diagram looks good.

[Kevin]

Kevin,

1 relay is all you need. That's how my driving lights are hooked up in the Tundra. I think I used a 30A which will be plenty unless you're running some "Baja offroad 17" gonna make the driver in the other lane blind" lights then at that point you may want a relay per light.

Diagram looks good.

Yeah, I'm just concerned about how well I'm going to run two sets of wires to each point on the relay and keep it clean. I guess I could run the ends of the wires into the female plug and crimp down before connecting it to the relay. Let me know what you think. Is there anything wrong with using two relays not for extra "power" but to keep the setup cleaner?

[brian c]

Kevin,

You're only running (1) wire from the relay (pin 87) to the + feed for the lights. Split that into (2) legs to feed either of the driving lights. The ground I listed is the ground for the relay and NOT the ground to be used to complete the circuit for the headlights themselves. Instead, ground the lights at the nearest good ground.

Is there anything inherently wrong with using (2) relays? No. It's just major overkill.

Looks like I'll need to hand draw something for you. Give me some time to come up with it for you. It's really simple stuff - you're really over thinking this a heck of a lot.

[Kevin]

Kevin,

You're only running (1) wire from the relay (pin 87) to the + feed for the lights. Split that into (2) legs to feed either of the driving lights. The ground I listed is the ground for the relay and NOT the ground to be used to complete the circuit for the headlights themselves. Instead, ground the lights at the nearest good ground.

Is there anything inherently wrong with using (2) relays? No. It's just major overkill.

Looks like I'll need to hand draw something for you. Give me some time to come up with it for you. It's really simple stuff - you're really over thinking this a heck of a lot.

Ok, thanks Brian. I've got it understood for the most part, but I haven't taken time to draw it out yet so that's why I'm probably asking so many questions. You've coached me through 3 wiring projects, so I know you'll get me set up here too. Thanks Brian.

[brian c]

Quick and dirty drawing:



The leg from the + Battery to Pin 30 on the relay should be sized to handle the current that the relay can switch. So if you buy a 30A relay, size the wire for the run to handle at least 30 A. And fuse that leg!!!

The leg from Pin 87 to your + lights should be sufficient to handle the power the relay can output. So if the relay is 30A size the wire for the total length of run to handle at least 30 A.

The keyed +12 source can be standard 18g wire as you're not using that much current to switch the relay.

Here's what I did for my Tundra:

* 30A relay under the hood right next to the battery.
* 8Gauge wire from + Battery to Pin 30 on the relay. Fused to 30A.
* 8Gauge wire from pin 87 down to the center of the car. That splits into (2) runs of 12Gauge wire which feeds the + side of my fog lights.
* 12Gauge ground wire from each of the fog lights to a good chassis ground.

From the cabin, I tapped into a keyed 12 source and ran (1) wire from the lit on/off switch through the firewall to the relay. That's the only wire that needs to run from the cabin through the firewall to the relay. Very tidy.

All my wiring is wrapped in convoluted tubing and zip tied to avoid any chance of an electrical fire. I'd recommend you do the same. A very good place to get this is Waytek. I bought 100' of the stuff for under $30 shipped.

[Kevin]

Oh yeah, that's perfect Brian. And I'm a HUGE fan of the convoluted tubing, I used it on my dash harness to protect from any chafing or fire. Thanks a lot this is perfect man!

Kevin