The Ultimate Headlight H4, Fog Light and Revers Light Upgrade Not LED or HID 1st Gen Tundra Addition

Sounds like the harness has some questionable wiring and/or loose connections.

 

Still odd that a fuse blew once unless a short to ground when jiggled or terrible relay?

then other two failures were blown bulbs?

worth measuring voltage at battery and comparing to the H4 sockets with low and high beam on. Should be a very close match. Any voltage drop Or fluctuations point to harness trouble.

 

No blown bulbs any of the events. I will look into it this week when I have some time.

 

Which harness did you install? From what source?

 

This one from Amazon:

$19 RENMAII-LIGHT 1Set 2-Headlight H4 Relay Harness, H4 Headlight Relay Harness H4 Wiring Harness H6054 7x6 6054 Headlight Relay Kit for 95-97 Tacoma 88-95 Pickup 4 Runner Fix Dual Ground Problem

https://www.amazon.com/gp/product/B089M4DC45/

So... using a multi-meter with the truck not running, my 12v AGM battery was measuring ~12.2v at the posts and around 11.7v at both H4 sockets (in the harness) with both the high and low beams.

Another puzzling observation: if I flick on the high beams while the fog lights are turned on, the high beam will not turn off when you flick it back to low beam; only the fog lights turn off/on, while the high beams stay on constantly.

Wondering if this harness just isn't intended for use on fog light optioned 1st gen Tundras?

 

That harness says its for a Tacoma of an earlier vintage, but is the same style I used for my 2000. The headlights and BCM integration changed around 2004 or so when the Doublecabs were introduced. The newer trucks are load sensitive for function as many have found out with the LED bulb swaps. Not sure if the harness is interfering with that and if a resistor would help like it does with the LEDs.

 

Check the OEM pinout to determine ground or power switched. My ‘02 is power switched when I expected it would be ground switched. Because mine is DRL enabled which basically means low beams on with ignition (which is dumb).

 

Installing now... just to confirm... the resistor gets plugged into the original plugs that are no longer being used... correct?

Edit... just installed the resistor on the passenger side OEM plug that is no longer being used. Before I had no low beam to the driver side, but high beam worked. Passenger side was fine. This solved that issue. So I just tape off the female side of the resistor? This is the one I'm using because it was laying around in the garage... although it's for LED according to the title. Seems to be working:

Xprite H4/9003 LED Canbus Decoder Anti Ficker Harness Error Free Resistor Capacitor for LED Headlight Bulbs, Pack of 2

https://www.amazon.com/gp/product/B07SGCHF5B?ie=UTF8&th=1

The resistor link in the original post doesn't work anymore.

Now the fogs won't work with high beams on. I suppose that's normal and need to do the fog light anytime mod? Or maybe try another resistor on the driver side, although the headlight services harness I am using already has something plugged into that.

 

Fogs do not work with hi beams. In any vehicle.

 

On my Tacoma I'm pretty sure we got them to work with the fog light anytime mod. I haven't tried it yet on this truck. Either way, it sounds like everything's working as it should so far. Edit. Oh I see you're talking about from factory. Thank you