Slee Headlight Harness Fail? (1 Viewer)

[Heckraiser]

I'll preface this by saying I suck at electrical and really have no clue.

My LX came with an aftermarket headlight harness wrapped in yellow loom, which I can only assume is a slee harness, judging by photos I've seen online.

My low beams are very unreliable. Sometimes I'll get a passenger side, but no driver, sometimes I'll get a driver but no passenger, on rare occasion I'll get both or neither. I used to be able to get both working by jiggling the wires (which seem to be bundled in a bit of a rats nest in front of the battery), but that is becoming a more rare occurrence. High beams are reliable, thankfully.

Any thoughts as to what might be wrong or where I should start looking? Should I just rip the thing out and replace with factory harness? Anybody experienced anything similar? Since I'm not starting from a stock "baseline" it's hard to know where to begin. I'd appreciate any thoughts or experience you could share.

Please and thank you.

:edit: I just wanted to throw in here, in case anyone interprets the thread title as bashing a vendor, that I'm just using internet jargon. Slee is a great company to work with and they did a great job tricking out my stepdad's 4runner. Good chance my electrical problem could be installer error anyway.

 

[SteamerF18]

I suck at electrical and have no clue as well, but I did install a Slee harness recently.

All of your stock wiring is still there, the Slee harness adds a couple of relays and better wiring to improve light output by pulling power directly from the battery.

Here is the link for the Slee installation instructions:

http://www.sleeoffroad.com/installation/headlight_upgrade_harness_v1.3.pdf

@NLXTACY did a write-up many moons ago that I believe became the Slee instructions and that thread can be found here:

Installing Slee's new style headlight harness

I can’t recall which of the LC wrenching demigods has commented on ripping numerous Slee harnesses out, but you may be able to track down issues similar to yours by searching. Thus far I haven’t had any issues w/ my harness and with the placebo effect of spending $ on my LC, I’m experiencing at least a doubling of lumen output. HTH

 

[Heckraiser]

I have read @NLXTACY 's thread, but I didn't realize the factory wiring is still all in there (hopefully, anyway). Taking a closer look at the slee instructions, it looks like my 30 amp relays were never secured to the inner fender (they are just hanging out loose in there). Seeing the warning "The relays should be installed with the wiring socket to the bottom." maybe the relay has been damaged by water getting into the underside? Would that be consistent with my symptoms?

 

[SteamerF18]

Not sure how to diagnose a relay for water intrusion.

Check all the connections, put some dielectric grease on, check the ground, connection at the battery and look for chafed wires. Outside of that you could disconnect from the harness and try the stock wiring, assuming it is there, to see if your symptoms go away. If it does, it is the harness or something related to harness install.

I’m sure someone more savvy on electrical can chime in on a better path. How far are you from Slee?

 

[western flyer]

My Slee headlight harness failed after 5 years or so of service. I just pulled it out and replaced it last month with a harness from a diff manufacturer (now running some projectors). This was not particularly hard or wet use. IIRC, someone else on here had similar a failure. Because of these failures, I also am not using a new Slee harness I have still in the bag that I was going to use to run some AM lights. I like Christo's stuff otherwise, just not their harnesses.

The Slee relays were hard mounted near the battery, bottom down. I am a big fan of dielectric grease on most all connections, btw.

 

[NateMob]

I have read @NLXTACY 's thread, but I didn't realize the factory wiring is still all in there (hopefully, anyway). Taking a closer look at the slee instructions, it looks like my 30 amp relays were never secured to the inner fender (they are just hanging out loose in there). Seeing the warning "The relays should be installed with the wiring socket to the bottom." maybe the relay has been damaged by water getting into the underside? Would that be consistent with my symptoms?

I had a basically brand new relay s*** the bed that came with a Baja Designs harness on my LT Tacoma. Symptoms were identical to yours til it eventually wouldnt work at all, turns out it went bad because its connections were face up, catching and holding water inside til it went on the fritz. I was told the same thing by their customer support; it needed to be mounted so water could run out of it.

 

[inkpot]

I bought my 80 in 2010 with a yellow Slee harness in it. After about a year of fiddling with it to keep lights on , I just pulled it out and went back to the factory harness that was still intact. Never could understand how using longer wires with extra connectors would make my lights brighter. Now I just run upgraded bulbs in the original wiring and fixtures.

 

[Tedward]

Slee harness removed.
Original harness in use.
Headlight issues solved.

 

[TXBruiser]

Slee Harness on both my 80s. The 93 went on the fritz so i removed it. The 97 is still there, but the first sign of issues im just going back to the stock harness.

 

[LINUS]

I had a crappy connector on the triggers from the Slee harness side, so years ago I nipped off the ends of the Slee triggers & added insulated male spades & T-taps on the factory headlight leads - solved everything (intermittent lowbeams IIRC)

Did that some 5-7 yrs ago, fixed it for good.

 

[Tedward]

Crappy connections and a relay that needed smacked 99% of the time.
After step #6 one night the whole shebang came out.
No hang over in the morning.

 

[L8Shift]

I bought my 80 in 2010 with a yellow Slee harness in it. After about a year of fiddling with it to keep lights on , I just pulled it out and went back to the factory harness that was still intact. Never could understand how using longer wires with extra connectors would make my lights brighter. Now I just run upgraded bulbs in the original wiring and fixtures.

I think the idea was to use the original headlight harness as the trigger for the relay, the relay acted as the conduit to power the headlights. The Slee harness provided the power directly to the headlights via the relay. Power itself to the headlights is more direct.

 

[Tools R Us]

I think the idea was to use the original headlight harness as the trigger for the relay, the relay acted as the conduit to power the headlights. The Slee harness provided the power directly to the headlights via the relay. Power itself to the headlights is more direct.

May want to check your EWD. IIRC, the power comes off of the main white wire in the fuse box by the battery, through the HD (50a?) relay, to the headlights. So the the aftermarket harness uses the output from the 50A relay to switch the 30A relay. On some older cars the power went all of the way to the dash, had benefit. Everyone of the aftermarket harness that we have measured, have delivered less, or best case same voltage as stock. At a loss to understand how the same or less voltage would make more light?

 

[gummycarbs]

The stock harness draws 12V pretty much straight from the battery, but the ground side goes through the harness, all the way to the light switch in the steering column, then to a ground. That adds some resistance.

As for a Slee (or other) harness going bad, if it uses one or more relays, replace them. They eventually go bad. I've probably used a dozen or more simple Bosch-type 30 amp relays over the years and I've had three go bad. One stuck on, one slow to switch, and one stopped powering the "normally closed" contact.

 

[Heckraiser]

I'm not sure if I'm more or less confused now, but these are some good ideas to look into. I think I'll start by pulling the upper radiator support thingy and just getting a closer look at what I've got. Visual inspection of the harness didn't show any damage to wires, but about half the harness is covered up anyway.

Slee is about 20 minutes away, but I wouldn't want to bother them when I'm not even the original purchaser, and they've no doubt got bigger projects to worry about.

 

[Mr Cimarron]

I had same issues as others. Went back to factory config. I did keep Slee auxillery harness for lights on bumper. Slee makes some awesome stuff but “upgraded” headlight harness is not one of them.

 

[JohnVee]

Relays. Swap the low beam and hi beam relays around and see if the trouble follows.

EDIT: And gently clean the contacts at all low beam connections. A brass brush or very fine sandpaper will do the trick.

 

[FXR UPR]

The slee harness I installed in my LX450 lost low beams after a few months. It ended up being a faulty relay. No big deal.

 

[Corbet]

I also would assume it's the relay. Simple solve if it is.

 

[ppc]

I'll preface this by saying I suck at electrical and really have no clue.

My LX came with an aftermarket headlight harness wrapped in yellow loom, which I can only assume is a slee harness, judging by photos I've seen online.

That may not be a correct assumption. I purchased a harness that looks very similar to the Slee harness from another vendor back in 1996 which was long before Slee Off Road came into existence.