seattlecard

Hi all -

I have a 94 SR5 4runner and am having the following issue:

Headlights work in low beam, but when I switch to brights, the headlights shut off.

Now, interestingly, if I use the hi-beam "flash" mode (pulling the handle toward me) the brights indeed DO come on. They just wont stay on when I switch it to stay.

Anyone have any clues?

Thanks!

RAD4Runner

Bad High-Beam contacts of your headlight dimmer-combo switch.

After you fix this, I suggest you do the H4 conversion harness, to fix the retarded stock wiring that leads to death of dimmer-combo switch contacts.

Shady Cadence

Please elaborate on this, as I have the same issue in the same truck.

seattlecard

Thank you - I found this link as a starting point: http://www.4crawler.com/4x4/CheapTri...eadlight_Combo

RAD4Runner

On Stock circuit:

• Wires are thin (AWG 18/20?)
• Ground circuit goes from bulbs, to cabin, to dash to dimmer switch, back to engine compartment to ground inside passenger-side fender (exactly a convoluted path as 4Crawler describes it), causing a lot of resistance, a lot of voltage drops and reducing voltage that actually reaches the bulbs.
• Dimmer (combo) stalk switch contacts carry high current (10 Amps on 60-watt high beam, 17 Amps on 100-watt high beams). This will shorten contact life.

H4 Harness retrofit will fix this.

Shady Cadence

Thank you. I had considered doing this when I priced a combo switch. Figure I'll just fab the harness a little differently to minimize costs. I'm beyond broke right now.

Shady Cadence

When I pulled the schematic to figure out the light issue I looked at it and just knew the current had fried the contacts, couldn't understand why they would wire it this way. Had planned on adding relays and re-working the wiring, but didn't figure you could dismantle the switch and fix it. SO going this route.

I knew of the circuit issues, just had never heard of "the H4 conversion" before.

RAD4Runner

If you're comfortable with a little rewiring and wanna minimize cost, you can try my method. Only required ONE relay and some wire.

I rewired this way.

Basically, stock control circuit is used to control relay. Relay contacts took the place of dimmer switch contacts.

wyoming9

iTrader: (1)

Was this issue ever fixed in the newer models??

If so what year or does it still continue in the 2015 models ??

I have yet to have any problems on any of the fleet.

I guess to many other maintenance items need attention .

To many projects not enough hands

RAD4Runner

They probably have fixed it in newer models. However, I haven't seen schematic yet.


Well... it's partly because Yota parts are made so robust, they withstand abuse, so we do not notice the problem on most trucks.

LOL! Yep! I'm currently unemployed but I still can't seem to find enough time to work on my truck- just lots of little details to fine tune here and there... rattles, etc. Nothing to keep me for daily driving or even road trips.

bswarm

You can find the wiring harness kit on eBay for around $25, and the H4 kit for about $85. There's a thread about this at https://www.yotatech.com/forums/f131...w-pics-235789/ You will lose the high beam indicator with the new harness. The headlamp difference is like night and day, well worth the money.

Shady Cadence

Love it! I WILL be going that route, even scrounged a relay out of the magic tool box drawer.

Did you ever wire up the HBI lamp?

RAD4Runner

Not yet. Havent had the chance to dig into wiring to modify. Stock config is also retarded. Uses LB to shunt across HBI lamp to keep it off, meaning current thru LB lamp still flows thru the LB switch contacts. I may just connect a current-limiting resistor from that positive side of HBI section to load side of stock headlights relay (as high a resistance as possible that wud still light up the HBI).

Terrys87

iTrader: (1)

Here is how I fix mine without replacing the combo switch https://www.yotatech.com/forums/f199...l#post51724567