headlight relay install - The 1947 - Present Chevrolet & GMC Truck Message Board Network

matt67350 · 12-08-2005, 12:30 AM

I did this to my trucks after reading this:
Brighter Head Lights @ madelectrical.com. http://www.madelectrical.com/electri...adlights.shtml

1 Read the artical
2 Parts list 2 bosch relays, spade connecters, wire, and inline fuse.
3 Look at wiring sheet
4 Decide that you can do this
5 Start by finding the 14LG and the 18LT wire on the back of the left headlamp.
6 Disconnect the (-Neg) battery cable. Mount the relays to the core support above the horn. You may have to make room for them.
7 Follow the 14LG wire towards the fuseblock. Mark it. This is the one to cut.
8 Follow the 18LT wire towards the fuseblock. Mark it 1st. Cut this one also.
9 Do the wiring:
cut 18LT (or low beam) and run the wire from the fuseblock to Terminal 86 on the relay.
run the other end and that comes from the headlamp plug to Terminal 87 on the relay.
cut 14LG (or hi beam) and run the wire from the fuse block to the Terminal 86 on the 2nd relay. run the other end to Terminal 87 of the 2nd relay.
10 Terminal 85 goes to ground.
11 Run a heavy wire (12ga.) from + Battery Post to Terminal 30 of both relays. Just run it through the stock wiring across the radiator. Add a inline fuse on this one.
12 make sure every thing is connected, secure wires,
replace (- battery cable )
13 Enjoy Brighter Head Lights

**Already Gone** · 03-14-2006, 04:53 PM

I'm going to put a new Painless Wiring Harness in my truck. Will I still have to do this relay thing so my Tri_Bar headlites will work like they are supposed to.?

jugadro · 04-30-2006, 09:40 PM

Will this stop my headlight dimming when I stop at a stoplight? Man is that annoying.

Longhorn Man · 05-29-2006, 12:13 PM

Already gone, your new lights will work, but they'll work better with this mod. Also, this mod reduces the amount of amps going through the harness, into the cab, through the headlight switch, through the dimmer switch... so they all have less of a load. It increases the amps at the bulb, sop they burn way brighter.
jugadro, this won't stop the dimming all together... you should look into an upgrade on your alt to stop that.

12-08-2005, 12:30 AM	#1
matt67350 Registered User Join Date: May 2001 Location: Benbrook, TX Posts: 1,060	headlight relay install I did this to my trucks after reading this: Brighter Head Lights @ madelectrical.com. http://www.madelectrical.com/electri...adlights.shtml 1 Read the artical 2 Parts list 2 bosch relays, spade connecters, wire, and inline fuse. 3 Look at wiring sheet 4 Decide that you can do this 5 Start by finding the 14LG and the 18LT wire on the back of the left headlamp. 6 Disconnect the (-Neg) battery cable. Mount the relays to the core support above the horn. You may have to make room for them. 7 Follow the 14LG wire towards the fuseblock. Mark it. This is the one to cut. 8 Follow the 18LT wire towards the fuseblock. Mark it 1st. Cut this one also. 9 Do the wiring: cut 18LT (or low beam) and run the wire from the fuseblock to Terminal 86 on the relay. run the other end and that comes from the headlamp plug to Terminal 87 on the relay. cut 14LG (or hi beam) and run the wire from the fuse block to the Terminal 86 on the 2nd relay. run the other end to Terminal 87 of the 2nd relay. 10 Terminal 85 goes to ground. 11 Run a heavy wire (12ga.) from + Battery Post to Terminal 30 of both relays. Just run it through the stock wiring across the radiator. Add a inline fuse on this one. 12 make sure every thing is connected, secure wires, replace (- battery cable ) 13 Enjoy Brighter Head Lights __________________ 69 swb stepside, rebuild and upgrade in progress Last edited by matt67350; 01-24-2009 at 09:24 PM.

03-14-2006, 04:53 PM	#2
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,144	Re: headlight relay install I'm going to put a new Painless Wiring Harness in my truck. Will I still have to do this relay thing so my Tri_Bar headlites will work like they are supposed to.? __________________ 1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021

04-30-2006, 09:40 PM	#3
jugadro that's right! Join Date: Mar 2004 Location: Topsham, ME, USA Posts: 101	Re: headlight relay install Will this stop my headlight dimming when I stop at a stoplight? Man is that annoying. __________________ 70-K20-4X4

05-29-2006, 12:13 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: headlight relay install Already gone, your new lights will work, but they'll work better with this mod. Also, this mod reduces the amount of amps going through the harness, into the cab, through the headlight switch, through the dimmer switch... so they all have less of a load. It increases the amps at the bulb, sop they burn way brighter. jugadro, this won't stop the dimming all together... you should look into an upgrade on your alt to stop that.



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