Electrical Gremlins II - Headlight Wiring

[hivewax]

OK, I'm focused on getting the headlights to work. The dimmer switch is toast and the ground wires are fried. I will need to ground the wires somewhere else other than the rusty radiator core support... likely the frame.

Can I use a toggle switch from Radio Shack to replace the floor dimmer switch? I'd like to put the toggle switch on the dash and not the floor, which is prone to get wet.

I'd like to keep it simple by following the original schematics for now. After I get the headlights working, I can do the headlight relay(s) for full potential lighting.

I replaced the turn signal switch and the fuse block. Brake lights work and turn signals kind of work... they flash fast in the back; probably has to do with park lights in the front causing the problem.

[basketcase0302]

You could run dedicated grounds to the lighting front sockets with confidence knowing that it will repair them, any other "cobbled" ground and you might be looking at the same issue. The faster flashing is usually an indicator of one bulb in the circuit not working properly, (I've never understood why though)...
Never heard of anyone using a toggle switch for the dimmer before-could probably be done though. Not real sure how LEO's would view a toggle for a dimmer though, (if you got pulled over)? I'd start with a 20A heavy duty single pole-double throw toggle. Still might not work properly until the harness to the lights is upgraded if someone's put halogen bulbs in the truck.

[hivewax]

30A toggle switch connected, but forgot to take a photo of how the old dimmer switch wires were connected.

Does #34 and #12 green w/black stripe go to power, #15 red w/yellow to ACC, and #13 red/black to ground? Click image to enlarge.




Ground wires are tightened to one of the front bumper bracket bolts on both sides of the frame. Wire wheeled to bare metal around the bolts for good contact. I'll paint over it for rust prevention.

[basketcase0302]

Loren, I hope you didn't turn that switch on like that?! That is a "single pole-single throw switch" meaning it only has an off and an on. You have to have a "single pole-double throw" switch. One leg of the switch is where power is fed to-and the other two legs get the power when the switch is thrown from one position to the other. If you wanted a lighted toggle it will wind up having four terminals,
1) power into the switch
2) low beam feed
3) high beam feed
4) ground for the light in the switch itself
(I'm not sure they make such a switch) maybe someone else can pipe in here on that?

Edit after looking at the above wiring diagram:
Wire#15 (red with yellow stripe) will be the 12 volt feed from the headlight switch (to dimmer)
Wire#12 (Green with black stripe) will be either low or high beams
Wire#13 (Red with black stripe) will be either low or high beams
Wire#34 (color not identified in diagram) will be your hi beam indicator (It will connect to the same terminal you find to be the hi beam-either#12 or #13.
I'll see if i can find a simple "one-line" diagram for the single pole-double throw switch and come back here in a few, that will make it so much easier to explain.

[hivewax]

Lucky for me, I had the headlight switch out also. If I did, I might of turned it on.

I checked all the switches at Radio Shack and all are 3-prong. The old dimmer switch is even 3-prong. I need to read up some more. I think the toggle switch I have is lighted red. Where does it light up?!

[basketcase0302]

Loren,
Here is a good "one-line" to describe a single pole-double throw switch:
http://en.wikipedia.org/wiki/File:SPDT-Switch.svg
I'm not sure if even Radio Shack would have it?
I know it could be found easily on the net.
BRB...
Here's a 15 amp, (not real sure how many amps our headlights pull-maybe not strong enough switch):
http://www.ebay.com/itm/Dedenbear-TSWRT ... 9d&vxp=mtr
And here's a 20A version that should be more than strong enough:
http://www.ebay.com/itm/Painless-Switch ... ae&vxp=mtr
You have to realize that our lights is what would be referred to as resistant wiring, (similar to a electrical heating element) that pulls a lot of power. Maybe the most power consumptive device in our truck besides maybe the heater fan motor?

[hivewax]

http://www.1728.org/project2.htm - Basic Electrical Switches

Wow, that price is not painless. Can this DPDT switch work? I can get it from Home Depot for under $7. Comes with 6 screw-in terminals. 20A, 12V DC.

[basketcase0302]

That should work, you'll only be using three terminals on it as it appears to be a "double pole-double throw".
Typically you would use three terminals on one side, (in a line with each other) of the switch for single throw application. I always throw a big red caution flag up when I see switches this cheap, too much china stuff on the market now.

[hivewax]

I'll do more research on the best quality switches at a decent price. Thanks.

[mr_josh]

Honestly, Radio Shack should have more than just those switches- do you have more than one Radio Shack nearby? My local RS has a very large cabinet with 12v switches (specifically for automotive applications) and at least a few SPDT options.

A SPDT switch will have three terminals. Check out this little graphic:

spdt.png

As basketcase0302 said, power will come from the headlight switch via wire 15, and head out to the high and low beams via 13 and 12. The dimmer switch just decides which way it's going to go.

FWIW, this would be a great time to add a relay to your lights (either one for both beams, or one for bright / one for regular). 30 amp 12v automotive relays are pretty cheap at Radio Shack, as well.

[hivewax]

Cool, thanks. Know where I can find Bosch relays or similar? Or, the relays at Radio Shack will do just fine?

[basketcase0302]

For a headlight upgrade? You can get KC light relays, (or similar brands) at most any auto parts store.
I've also got a seller in my evilboy favorites, (if you want to upgrade your headlight sockets as well), to ceramic-versus the original plastic crap. Not really sure if the guy ripping folks off here was including this in his "headlight upgrade harness" or not. But it should be done, as it is a known weak link in the wiring.

[hivewax]

Yes, I would like the link to the ceramic sockets! Mucho gracias. And, please add anything else you think might help with the headlights.

[hivewax]

Do I get the H4 / 9003 or H4 / 9145 ceramic sockets?

[basketcase0302]

Uh-oh...put myself on the spot LOL! I had to filter through my sellers and now can't find the seller. I know I'd have an invoice here somewhere-but dodging tornadoes right now isn't a good time to look for it.
Here's one seller I found though that has a "plug and play" type replacement socket.
http://www.ebay.com/itm/CERAMIC-H4-HI-H ... 48434ffdca
I'm not real big on adding more wiring connections-it usually is just another weak spot down the road. I opted for the solder type sockets-sorry I can't find them right now. I believe that LMC and maybe one more company make the entire harness with relays and possibly sockets too. maybe someone who has done that harness can chime in here?