1999 Tahoe Headlights

[writer]

Is it normal for high beam lights to only be the center headlights and the low beam to be the outer headlights? I thought all four headlights should be on when you turned on the high beams.

 

[lesterl]

That is normal, either or, now if you install a relay you can have all 4 on with high beams, I have done that for years with all my composite headlights.......

 

[writer]

Thank you. How did you connect the relay?

 

[lesterl]

Find the wire that feeds the Low beams, find a good spot to do some wiring (on mine it was between the core support and the washer fluid resivoir, cut that one wire.

[Common] terminal on the relay goes towards core support on that wire.
[NC] terminal goes towards resivoir on that wire.

These 2 complete the low beam circuit when deactivated.

[NO] terminal needs a fused feed off one of the battery studs on the fuse box.

This fused feed (about 10 amp is what I use) will power the low beams when the relay is activated.

Ground one side of the coil on the relay.
Other side of the relay coil gets tapped into the high beam feed wire.

Colors on my rig were.....
Low-Tan
High-Lt Green

1995 Tahoe.....

 

[lesterl]

As a side note or just for a laugh (I have been wiring and doing electrical/electronics for many years) when I wired this up on my 95 a couple months ago when I got it I got the COM and NC backwards so it did nothing.......

 

[writer]

Thank you .. I will give it a try.

 

[lesterl]

Good luck....

I attached a pix of the relay on my 95 to maybe give you a hint or so......

 

[writer]

That is very helpful. It will make a difference.

 

[lesterl]

The brown lead running to the Left is a power feed thru a 10A fuse from the fuse block, the black ground wire is just grounded to a scuffed up bare metal on the washer fluid resivoir, the other 3 wires just splice into the harness above......

 

[writer]

The picture you sent is a great help. I think I can see five wires .. is the relay you used a DPDT or SPDT? My relay understanding is limited. When I look at the bottom of the relay I see numbers .. 85 and 86 are coil indications, 30 is the common and 87/87a or 87b are switches either normally closed or normally open. Please forgive my simple questions. The brown power feed, which number on the relay does it attach to? Does the ground wire go to terminal 30? I see two red wires and a yellow wire, what terminals do they attach to on the relay and what wires do they attach to in the vehichle wiring harness?

 

[lesterl]

It is a SPDT relay, common automotove 30A relay.

The brown Power feed feeds the NO terminal (because when we activate the relay we want to supply power to the low beams), the low beam wire gets cut and the side going towards the front of the truck gets the COM terminal (because we either want it operating off the headlight switch when low is selected or getting its own power when hibeams are on), the NC contact will be on that cut line but headded back to the cab side because when the relay is deactivated we want that circuit to be complete.

One side of the coil gets grounded, the other gets TAPPED into the highbeam feed so when hibeams are on the relay gets activated.

Hope this helps......

For extra stuff might check out www.the12volt.com I love that site for car stuff.......

 

[writer]

Thank you .. I already found the www.the12volt.com site. I agree, it is very useful. Your guide fills in the blanks for me. We are going to Atlanta for a few days .. I will try this when I get back and let you know how it goes.

 

[lesterl]

Cool, let us know how it goes....