I'm having trouble with the headlights on my '90 4Runner SR5 (canadian version, i.e. daytime running lights). Initially the truck had a set of headlights in it for 10 years+, never burnt out, and on all the time (120K km), just your basic sealed beams (Sylvania's I think). Then they both burnt out within 2 weeks of each other. No problems, just replaced them.

The problem now is that they burn out every 6 months or so, both lights. I've tried multiple brands, (Sylvania, and GE Nighthawks) and it makes no difference. I tested the voltage to them and they're getting 14.5V while engine is running (same as battery while charging).

Does anyone know why this may be happening and/or have a fix for it? Its frustrating to say the least.

Thanks for the input.

 

Did you try reading the amperage going to the bulbs? Clean the connectors real well and check the harness for any chaffed wire.

 

I cleaned the connectors, but didn't check amperage. I assumed if for some reason they were drawing too much, the fuse would blow.

I'm not sure if its possible to have too high an amperage since V=IR, unless there was a short... not sure, just thinking out loud.

 

Thats true....but you could have wires rubbing, broken or hanging on just enough to blow the bulbs, but not the fuses. They should be seperate fuses, so you should find something in the schematic that has them both in common. You never know, electricity does weird stuff, I'm a helicopter electrician, I'm seen some crazy stuff..lol...........Are you touching the surface of the bulbs when you replace them? That will shorten the life considerably.....

 

Likely you have the dim DRL feature on your truck. if so, that will kill high end halogen light bulbs in short order. Why? The voltage is too low with the DRLs on and that kills the halogen bulb lifetime (the halogen cycle in that type of bulb needs a certain temperature to work):
- http://www.4crawler.com/4x4/CheapTri...ghts.shtml#DRL

Two options are:

1. Use plain old sealed beams, nothing fancy.
2. Upgade the wiring harness and bypass the dimming DRL mode and then you can use high end halogen bulbs.

 

My DRL's are OEM, but since its a 1990 (the first year they were required in Canada) its not any different from just turning on the switch. All headlights, taillights and dash lights come on at full strength. The only difference is when the headlight switch is on, the interior clock gets dimmer and it allows me to use the brights.

 

Might want to test the voltage at the headlights (under load) and see what value you read:
- http://www.4crawler.com/4x4/CheapTri...ryBeforeYouBuy

A buddy of mine had an early '90s 2-door 4Runner from Canada and it had a reduced voltage at the headlights and he was burning up headlight bulbs every few months. After installing the upgraded harness, he has not had any more issues w/ bulb burnout. You can maintain the DRL feature, just bypass all the 17 year old factory wiring.

 

Thanks for the insight, I'll give it a shot.

 

just a idea here but maybe back when you had the old lights they where made better than todays standards.
look at house hold lights back in the day bulbs used to last a lot longer then todays light bulbs they make them cheaper to keep the cost down and in the process the bulb dose not last as long.

 

But what happens if you start it up, headlights off, release the park brake, does the headlights come on via the DRL relay? I bet it does, and it runs at 40% which is less than stock and the prior posters story on low vaoltage my have merit.

 

When I start my truck, headlight switch on or off, e-brake on or off (makes no difference) the whole truck lights up just as it would with the headlight switch on. It doesn't operate as most newer vehicles DRL systems where its tied to the e-brake to shut them off and there is no dimming feature. I suspect since '90 was the first year of the legal requirement in Canada, it was a rushed job by Toyota to get them released which is why they aren't very sophisticated. It makes it very frustrating at a drive-in theater...

My friends '90 Supra does the exact same thing (wrt the DRL) only instead of headlights, the fogs come on.

 

Where's the voltage regulator on 4Runner's? Internal to the alternator?

 

Should be internal.

 

I have disabled a 90 4Runner DRL system, and it didnt work that way at all. Had its own DRL relay under the radio etc. And the headlamps only would come on and run at 40%, then when the headlamp was switched on, it would run the headlamps at 100% plus turn on all the lights. This sounds like a US rig that was just wired to come on when started. Maybe it was "imported" to Canada?

 

Definitely a Canadian edition. I bought it from the original owner who bought it in Canada plus the speedo and odo are in km as the primary. I'm pretty sure its normal that way due to my friends Supra of the same vintage behaving exactly the same. I know that the system did get better in the following years ('91, '92 etc)

Any other 1990 Toyota Canadian owners who can comment?

 

Its possible the system failed and somone just wired the headlamps "on all the time", easily done by just grounding a wire at the combo switch. Just a thought.

 

don't touch the actual bulb with your fingers, hold it by the plastic connector

 

Sealed beams in '90 - not really an issue.

 

I have a 1991 4runner Canadian Limited Edition. And i have the same problem as mkt478. when i start my engine all my lights (except my dash lights) come on. unless i have the e brake on. But i would like to remove the DRL feature from my truck so that my lights last longer. And down here in Belize only the crazy people drive at night due to the big pot holes that you cant see. And i only drive at night when it is an emergency. But if you would please let me know what the easiest way is to remove this DRL feature from the Canadian version.

 

See:
- http://www.4crawler.com/4x4/CheapTri...ghts.shtml#DRL