FirstDiesel- about Headlight Wires

**ucdavis** · 08-25-2003, 11:41

FirstD,
In a recent post you sounded like you'd been thru some headlight wiring "issues" with success. I'm hoping you can elaborate on the problem.
I've noticed the headlight dimmer rheostat heats up significantly on my rig (on/off switch is rocker type, next to a wheel-type rheostat dimmer in a combined unit; same used on many GM cars of my vintage) and have wondered if that is, as Martha would say, "a Good Thing?"

**FirstDiesel** · 08-25-2003, 13:44

I have not been through wire issues. I prevented them. Bought a Kennedy harness. If you take off your headlights and look at the size of the wires there it will make you wonder how GM ever though drawing all the power throughb wires of that size would work!! And all the current goes through the switch too, no relay.

Bought the Kennedy harness and it has numerous advantages.

1. You get decent size wiring
2. You get relays controling the lights so the switch only runs enough current to control a relay.
3. The lights get full voltage and get very bright.
4. There is an option to make the low beams stay on when you turn on the high beams.
5. It took only about 25 minutes to install

StephenA · 08-25-2003, 15:17

Now that's what my lights need! How much? Does he make an ignition upgrade too?

**HowieE** · 08-25-2003, 15:31

The dimmer resistor is wired in series with the instrument lamps and depending on how bright you run our instrument lamps will determine how hot the resistor gets. 12 volts will be dropped across one or the other. i always run my instrument light at full bright to reduce the heating in the resistor.
In general the GM headlight switche are grossly undersized and the wiring leading to it is equaly undersized. While the headlight kit will improve your headlights brightness resulting from the undersizing it will not effect temperature resulting from the resistor.
Take a look at my web page to see another way this switch fails. If the parking lamp load is increased with a trailer the parking light circuit connector in the headlight switch will melt.

**ucdavis** · 08-26-2003, 17:25

Thanks for the replies.
I'll take a look @ wire sizes & see if there's something I can do on my rig (its different than yours in that headlights & their wiring is installed by the motorhome manufacturer rather than GM).

**FirstDiesel** · 08-26-2003, 19:26

Look under truck accesories on Kennedy's website.

135 bucks I think and well worth it.

StephenA · 08-27-2003, 07:07

Nice website Howie... Since I tow a 31' TT, I'm interested in rigging up the trailer running light relay you devised. My switch is fine, so the resistor isn't fried. I haven't opened the switch, but when I do, I'm considering wiring in a bigger resistor with a heat sink, maybe, unless you think the stock resistor will be fine once the relay is rigged. [I'm going to install JK's headlight harness as well.]
Where did you get the power for the relay - off the fuse box? Did you leave the Sub running lights as they were and use the relay for the trailer lights, or does the relay power both? Could you fax or email me a drawing?
Thanks, Stephen

**LanceW** · 11-26-2003, 21:12

I know this is an old topic, but... I've been having parking/marker light problems too lately. I finally went and bought the new switch kit and new wiring block- mine looked just like the autopsy pics on HowieE's website.

I'm only posting this reply because I skinned this cat a different way- I ran a separate toggle switch from a hot blade (labelled "green") in the box to my trailer harness. I used a 5-amp inline fuse, a 25 amp toggle switch with an LED drilled through the dash, and popped it into the parking light wire. The added advantage is that it's on a separate circuit from the truck's lights- easier to flash a 'thank you' to the trucker that just let me in.

I have also added a headlight relay kit to the wish list- going from a headlight switch with 196,000 miles on it to a brand-new one makes a difference that is literally "night and day".

**G B Sisson** · 11-27-2003, 09:41

HI, I'm right in the thick of this one. I have a new switch ordered from NAPA,it's only 14.00 and easier to get in my island location,should arrive Friday.I intend to do the upgrades too. Anyone feel the GM switch is better quality?I could pick one up next time Im in town to use with the proposed Kennedy components... Thanks, GB

**BETA** · 11-27-2003, 11:53

Sometime ago, there was an article on the DP regarding brighter lights - maybe it's time to re-run it!

**VinDiesel** · 11-29-2003, 14:24

Glad to see this thread started. The low beams on my '98 are miserable even after installing the Kennedy harness. The voltage at the bulb (lights on, engine running) is 13.86 and 12.17 lights on, engine off. Great care was taken grounding the harness; that shouldn't be the problem. Is there something else I can check to be sure I didn't mess anything up? I am running Phillips 9006's rated at the usual 55w. (Highs seem fine but how often can you use them??)

**Scooby** · 11-29-2003, 17:52

I just polished the plastic lenses on my 96 1500. There was a night and day difference in my lights. My low beans are as bright as the high beams used to be !! I got the polising kit off Ebay, for 19.95 I believe. It took about 10 minutes, and I did the tail lights too. WOrked great.

**VinDiesel** · 12-01-2003, 10:31

Scooby-several others seem to repeat the polishing experience outcome. I assume since you said "plastic" that you have the composite version of headlamps. In mine, the low beam bulb sits behind some kind of diffuser which is inside the lighting unit and doesn't look easy to get to. I assume this is not what got polished. Also, I assume it is not easy to tell that polishing is/isn't needed from visual inspection of the outer, exposed covering lens. Mine "look" very clear. Please confirm assumptions as it will help to decide whether to polish or go with a sealed beam system upgraded to CIBA lamps. Note to Beta: agree! If there was a detailed article on brigher lights, it might be useful to those of us who missed it to either bring it back or provide a reference should it reside in the archives (I have the floppies from the last couple of years per order.)

jspringator · 12-01-2003, 14:51

Vin, by your commments, I presume you have a base model that has the sealed beam units. If this is the case, you are in luck. Get Cibe or Hella E-codes {European Spec} to replace your sealed beams. I have been tempted to change out grills so I could switch! I have E-codes on my Miata; they are the best. You can use any size low beams you want with the Kennedy harness, and still won't get flashed.

**G B Sisson** · 12-01-2003, 21:34

My new headlight switch arrived today at the local Napa store.(Made in Taiwan).I willput it in tomorrow. Havent had time away from work to lookinto upgrades yet.Is the poor switch design only problematic while towing?I guess what Im asking is if I dont tow again till next summer is it fine the way it is as stock? Thanks GB

**VinDiesel** · 12-01-2003, 22:35

James- I wish! I have been looking into a grill swap as it seems the E-spec is really the only way to get legal improvement. I've been in touch with an outfit called Daniel Stern Lighting. DS put me onto this possible mod; I just don't know if it's as simple as a grill swap. DS can fit the wiring and some E-spec'd sealed beams. I'm not sure if that's all there is or whether the sealed beams are bigger and won't fit in place of the composites. I'd hate to have to make a spot for them but I'm going to continue looking into this mod as I'm now convinced it's the best solution. Thanks for pointing out that the Kennedy harness won't be wasted!

**Bobbie Martin** · 12-02-2003, 05:15

I did the swap on our 95 Suburban. I can tell you in addition to the grille you will need the headlamp buckets, springs, adjusters, turn signals, etc. It's a pretty easy swap - all the holes are already there. I was able to find a complete grill assembly on ebay, but the grille is pretty big so shipping can be a problem. I bought new springs, adjusters and plastic nut inserts from the dealer for a few dollars, also got a new bowtie as well. One more thing, there are two metal nut inserts you need as the sealed beam grille has two additional mounting screws behind the headlamps. The holes are in the radiator support for these as well. You will need new wires and relays, I made up my own wiring harness with new high amp connectors. The stock wires are so small I worry about them triggering the relays! You can get all the wiring accessories you need from Daniel Stern. The turn signal bulb holders will fit with no modification. There are two additional parking lights the composite grille uses you have to remove, which is no big deal. And yes, its well worth the hassle. One more thing, the composite lights & grille usually bring a good price on ebay, so you can recoup some of your cost by selling the old parts. If you look in the photo contest topic you will see a picture of my Sub with the Cibies & grille.

**Scooby** · 12-02-2003, 07:01

I didnt know there were different headlight configs on these trucks. Mine are plastic on the outside, (lens), and a reflector on the inside that the bulb module is plugged in to. I have not changed the headlight bulbs yet, so I dont know how it is all put together. My truck has the same type as my wife's Grand Prix, except her outer plastic is much clearer than the ones on my truck. I also polished hers, and she noticed a big difference too.

**HowieE** · 12-03-2003, 15:52

Gentelmen we are talking about 2 completely different issues here.

The only connection between the headlights and the parking/instrument lights is that they both are routed throught the headlight switch. It end there.

The headlight problems, low light levels in the low beam mode, can be corrected by upsizing the wireing by a harness and relay kit for JK. This will improve the light level of the headlights but has no effect on the dimmer that controls the parking/instrument lights.

The dimmer control for the parking/instrument lights will function OK as long as you do not add any additional load like a trailer with more than 2 or 3 marker lights on it. If your trailer has a number of marker lights and you do not relay that load you run the risk of melting the connector on the switch and in some cases melting the wire just beyound the connector. GM knows of this problem and will sell you a replacement connector with the same size wires as those originaly used so you will come back for another kit in time.

Kennedy · 12-03-2003, 16:03

Howie "MacGyver'd" mine at the Rendezvous in OH. The park lamps wouldn't go. Trailer clearance lights were just too much.

Draw Tite makes a "Modulite" relay setup. It is a smart play device that pulls 12v from the battery and distributes to the trailer plug. I used one of these on my Iveco as it had the seperate turns/brakes and I needed to tow trailers...

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