Headlight problem persists after new bulb

[RMcG]

SOLVED: I AM EDITING THIS ORIGINAL POST SO THAT READERS CAN UNDERSTAND THE CONCLUSION (SOLUTION) OF THIS THREAD.
AS STATED IN MY POST AT THE END OF THIS THREAD "I THINK THE MAIN PROBLEM WAS THAT THE FEMALE PLUG WAS NOT FULLY PLUGGED INTO THE MALE
PRONGS OF THE NEW HEADLIGHT BULB. THIS POINTS UP ONE OF THE PROBLEMS WITH REPLACING THE BULB "BY FEEL" INSTEAD OF "BY SIGHT" AS
CAN BE DONE IF YOU TAKE THE BUMPER COVER OFF AND TAKE THE HEADLIGHT ASSEMBLY OUT OF THE CAR. I THOUGHT THE BULB WAS FULLY PLUGGED
IN, IT FELT LIKE IT WAS FULLY PLUGGED IN, BUT IT WASN'T." The technique of replacing the headlight bulb without taking off the bumper cover is
discussed at the end of this thread Advice needed for replacing headlight bulb
that was started (and essentially ended) by me just before I started the present thread here.

Thanks,

The Original Poster, RMcG

Hi everybody:

I thought replacing my passenger side headlight bulb would solve my headlight problem as described in my recent
thread/post: "My low beam passenger's side headlight is abnormally dim (much dimmer than the driver's side headlight).
The high beams are normal and equal on both sides, so it appears that the passenger's side bulb is almost burnt out."
(I think my passenger side running light was also out at that time too.)

I replaced the bulb today with a brand new Sylvania Silverstar 9003; and I tried to carefully clean the old dielectric grease from around the
connector and the contacts of the new bulb with mineral spirits, a toothbrush and Q-tips. But, I am still having passenger side
headlight problems: no running light on the passenger side and a dim passenger side headlight on low beam (and also with fog light on) and now I
have no high beam on the passenger side either. I had a normal high beam on the passenger side before -- I think. The driver's side headlight
appears to be behaving normally.

Now I am wondering, what should I do next?

I could check voltages with a multi-meter. So, for example, this forum thread (post #6) says: "For 2007.
Left Hand. Green Low Beam,Brown Hi Beam,Grey Common.
Right Hand. Blue Low Beam,Green Hi Beam,Black Common."

And this thread (post #2 from Australia) has a Diagram that I have inserted below that gives voltages and ground for various headlight switch positions.

Maybe it's a blown fuse or a relay problem. I don't think Chilton's has pictures of fuse boxes, And I have looked at wiring diagrams in
the library's Chilton's and they are hard to understand. I have attached a picture of the actual fuse box cover under the dash on my driver's side of the car.

Recently the lights for the lower dash circular knobs for fan speed, air flow direction/defrost and air temperature are no longer working
(see attached) picture). Also the headlight on reminder alarm went out several months ago. I can live/drive without those lower dash lights,
but I can't drive at night without headlights.

Questions:

Does anybody have suggestions as how to find relevant fuses and/or relays?

Would the wiring and voltage information given above from other posts apply for my 2008 Hatchback base model?

Does anybody have any suggestions as to what I should do before consulting/spending a fortune on, a mechanic/dealer?

Would a dealer or independent mechanic be able to diagnose the problem relatively easily? Say using on board diagnostic
testing?

Any other comments will be welcomed.

Thanks,

R.

[RMcG]

Update: I am feeling somewhat more encouraged today that I have a fighting chance to figure out the source of this problem. But I’m not sure I can do it.

QUESTION: If I do end up taking the car to a mechanic, do people recommend a dealer in place of an independent mechanic, since it is an electrical problem?

An interesting tidbit: there is low power to both headlights with the headlight switch turned to the lowest position ("the dot," on page 139 of the Owner’s Manual,
Headlight Switch, attached). . (This is a lower power than the running lights.) But according to the owner’s manual it seems like the headlights should not come in that
lowest position. Only the “side marker, parking, tail, license plate, and instrument panel lights” should turn on. (Again, see page 139 of the Owner’s Manual, Headlight
Switch,attached. I don't have foglights.)

A summary of the behavior of the headlights:

The driver’s side (left) headlight seems to be normal.

The passenger side (right) headlight seems to only have low power with the headlight switch turned to the lowest position or turned to “headlights on.”
There are no running lights, low beam or high beam for the passenger side headlight, even though I put in a brand new Sylvania SilverStar bulb a day ago.
There is just the lower power to the right headlight (and the left headlight) with the headlight switch on the lowest position ("the dot," on page 139 of the attached
owner's manual, see below). This lower power seems to be equal for both headlights in "the dot" or lowest position. But the driver's side headlight gets more power
(and brighter) as a running light, low beam and high beam. But the passenger side headlight stays the same low intensity for lowest position (the dot), running lights,
low beam and high beam.

I figured out how to test relays today and tested the three relays in the small fusebox near the passenger side headlight and they were all good. I will check
some more fuses and relays tomorrow. I'll try to check voltages at the input contacts to the headlight bulb by making a male probe that can stick into the
female plug. And maybe I can make enough sense of the Chilton’s wiring diagram for the headlight to help figure out the source of the problem.

Any comments from anybody will be welcomed.

Thanks,

R.

[bronsin]

I’m afraid the only question I can answer is it wouldn’t matter what you took it to a dealer or an independent shop.

[RMcG]

Originally Posted by bronsin

I’m afraid the only question I can answer is it wouldn’t matter what you took it to a dealer or an independent shop.

Thanks for your reply bronsin. I asked the question, because I have had the impression (but am not sure that it is true) that when you have a complicated problem, it is better to go to a dealer. And this seems like it could be a complicated problem if it is a wiring problem: I am not sure if the recent failure of my headlight on reminder alarm, no illumination lights for the central/under the dash controls (fan speed, air flow direction, blown air temp) and headlight problem are related or not. If they are related, it seems like it would be a complicated problem.

As everybody knows, dealers tend to be significantly more expensive than independent shops). So I am interested in people's thoughts about dealer vs independent shop for this problem and will welcome anybody else's opinions on this.

Regardless of what happens, I will post what the end result is. I feel that this is the major & best way for me to give back to the forum. I try to give back as much to the forum as I can, rather than just take, so to speak. But my knowledge & expertise is limited for doing this.

Again, any other comments will be welcomed.

Thanks,

R.

[sh0rtlife]

ok first off any shop s going to screw you out of alot of money so dont

firt thing first check your relays and your fuses the passenger side fuse box as i recall is the high/low relays and drl...honestly since you have no way to "test" them..turn on the headlights and remove one if the light you have goes out, then you verifyed the "socket" for the relay, at this point you can remove and swap the other relay in there to that socket..if the bulb fails to light you have abad relay in your hand.....im pretty sure toyota ran 1 relay per side..so theres a good chance you have abad relay

next thing we need to verify is if were getting voltage to the socket or if the bulb is bad..brand new items can be faulty
swap the good OLD bulb from the passeneger side into the driver side socket and see if it lights DO NOT install it into the headlight housing

if it lights then the new SS is bad

if it doesnt light first thing to check is a ground issue for this youll need a length of wire as i prefer to prove the issue WITHOUT a meter
i need a little time to go out and verify the yaris wiring..as not every manufacturur wires the H4 bulb the same, some power the main conector and GROUND for high/low while others ground the main and power high and low independently..the bulb doesnt care and will work both ways


99% of the time on a bad bulb its either a fuse, relay or bad ground and a simple fix..the other 1% is a headlight switch

the fact you have 1 side working also leaves the option to bypass everything and make a mini harness using a couple relays and conectors ..same harness they give away with HID's...yes it sounds like alot but "if you have some catostrophic hiden wiring problem(as unlikely as it is) this would be a perminant fix

anyway gimmy a couple hours and ill report back on the verification of power/ground on the yaris and see if i can lead you further down the road of fixing it...

hell come give me 100$ (labor)and ill sort it out for ya..worth the drive to save ya money?
i used to have a shop..long story short my partial buisness partner lied,ripped me off and took the shop..so i do it all by word of mouth and out of my 30x20 shop at home..i still hold the buisness name and logos

[RMcG]

Thanks for your reply sh0rtlife, I appreciate very much your encouragement:

I figured a bunch of stuff out today, to a great extent by following your suggestions. First I unplugged the Sylvania SS headlight bulb. And I immediately saw that I still had a lower power light in the right (passenger side) headlight, so that light is coming from an other bulb and not the Sylvania SS bulb. That other bulb may function something like one of the "fog lights." But like I said in my previous post, I have a base model Yaris and I don't have fog lights per se. So I have no fog light switch as described on page 141 of the Owner's Manual. Anyway this other bulb clears up some of the confusion I had about the lowest ("dot") setting on my headlight switch. Put simply, the Sylvania SS was not involved in providing that lower power light.

I measured voltages. I unplugged the headlight bulb and measured voltages in the 3-receptacle female plug (see diagram my first post) with a small volt meter (part of a cheap multimeter) by plugging the pointed metal probe into each of the three receptacles and touching the other probe to ground. Here is a partial summary of my results (regarding top, left, & right, the plug is oriented as when it is in use with a bulb: right passenger & left driver side). I am giving the results in terms of voltage difference in volts for various headlight settings:

Running Lights: Top +9, Left 0, Right 0
Low Beams: Top +12, Left 0, Right 0
High Beams: Top 0, Left 0, Right +12

Next I took the new Sylvania SS headlight bulb and "bench tested it" in my apartment using the 12-volt Schumacher SJ1329 jump starter I bought (see post #10 of my thread Advice needed for buying a jump starter). Basically used some wires, alligator clips and the jump starter to replicate the voltage differences I measured. And I was able to get both low beam and high beam to work! Go figure!

The only explanations I can think of is 1) somehow I didn't get the plug in far enough on the bulb when I plugged it in or 2) there was some dielectric grease (from the factory installation) that got into the 3-receptacle female plug and/or on the male bulb contacts, or a combination of 1) & 2). (There was some grease on the male bulb contacts that I cleaned off with mineral spirits.)

So, finally, I took the new SS bulb back out to the car and plugged it in (without putting the bulb back in the headlight assembly) and it worked!: I was getting light in low and high beam settings.

So my plan tomorrow is to do the final install by sliding the rubber boot back over the 3-receptacle female plug & wires , then plug in the SS headlight bulb (without putting the bulb in the headlight assembly) and make sure the bulb is working. Then finally put the plugged in bulb back in the headlight assembly; all without touching (or getting dielectric grease) on the glass of the bulb. Then I'll secure the bulb in place and put the boot back in place by feel as described in my post #21 of Advice needed for replacing headlight bulb

QUESTION: Does anybody have recommendations for cleaning dielectric grease from the contacts in the 3-receptacle (female) plug?

(I tried to use mineral spirits and an old toothbrush to try to clean the factory installation dielectric grease off those contacts, but I am not sure it worked.) The mineral spirits I bought (Klean Strip Green) are in a plastic container, so I am thinking they will clean the grease, but not mess up the plastic of the plug.

Regarding checking relays, I'll post something in my next post about how I did that, so perhaps some people may learn from it.

Thanks again sh0rtlife.

Any comments from anybody will be welcomed.

R.

[komichal]

Does anybody have recommendations for cleaning dielectric grease from the contacts in the 3-receptacle (female) plug?

I would just spray the bastard with a full can of brake cleaner (put it in some big jug or something so that the brake cleaner does not flow all around).

[RMcG]

I finally have the new passenger side headlight bulb installed and working properly. I think the main problem was that the female plug was not fully plugged into the male prongs of the new headlight bulb. This points up one of the problems with replacing the bulb "by feel" instead of "by sight" as can be done if you take the bumper cover off and take the headlight assembly out of the car. I thought the bulb was fully plugged in, it felt like it was fully plugged in, but it wasn't.

I kind of followed komichal's advice to make sure that dielectric grease was not interfering with the electrical contact, but I used a degreaser instead of brake cleaner. I did this, because brake cleaner can cause plastic to degrade. I put the degreaser on the prongs of the old bulb and repeatedly inserted the old bulb into the female plug to clean out the female plug. I also tried to degrease the socket for the bulb in the headlight assembly and the rubber boot using degreaser on a paper towel and with a gloved hand (thin disposable rubber gloves).
I used this CRC Degreaser; it says specifically it can be used on plastic and rubber.

I also sprayed the bulb with Brake Cleaner and used a Q-tip with Brake Cleaner on it to clean the bulb, I thought the bulb might have grease on it. And I was especially worried about the glass on the bulb.

I wanted to use dielectric grease on the boot (to keep it from sticking to the bulb in the future) and also on the plug after the bulb was fully connected, to keep water out of the plug & contacts. So I slid pieces of plastic straw over the electrical bulb prongs to try to keep the grease off the prongs. This strategy worked to some extent.

I ended up using the following sequence to install the bulb: 1) I just put the new bulb back into the socket by feel and secured the bulb in place using the metal clip. I have had enough practice doing this that it was not too hard. 2) I used a Q-tip to put dielectric grease on the metal around the circular edge on the back of the bulb. I tried not to get any grease on the bulb's metal electrical prongs. 3) I slid the boot over the metal prongs and tried to secure the boot to the back of the bulb with my finger and by pushing a screwdriver against the rubber rim inside the boot as described in post #2 of my other thread here. I could only feel what I was doing and I am not sure I really got the boot fully around the metal collar on the back of the bulb, but the boot fit well enough.
4) I slid the plastic straw pieces off the bulb's metal prongs (some fell off with all the prior manipulation). Then I put Degreaser on my gloved (thin disposable rubber gloves) fingers and tried to get any grease off the metal prongs that I could get. I also used a piece of a paper towel with Degreaser on it too and tried to remove grease from those metal prongs. 5) After letting the Degreaser evaporate, I plugged to female plug onto the metal prongs and tested the headlight to make sure it was working. It was: I had running lights, low beam and high beam on the passenger side. 6) Finally I put dielectric grease over the plastic plug that is now plugged in the back of the headlight bulb.

I hope this helps somebody else who wants to replace the passenger side headlight bulb without taking off the bumper cover. I will not replace the driver's side bulb until the weather gets warmer and less rainy here unless I have to. I may take the bumper cover off to do the driver's side, I can appreciate the advantages of that approach now.

I "lost" a 10 mm socket that I used to move the small relay box behind the passenger side headlight assembly, it fell down onto a plastic ledge behind the headlight.

I decided not to slide the boot back over the plug and then plug the bulb in before mounting it in the socket. There just did not seem to be enough room for this and getting the socket mounted without all this stuff hanging on it was hard enough as it was.

Thanks to everybody for their input, especially sh0rtlife, and also bronsin and komichal.

R.

[Compeer]

Kind of related I had a dim headlight and could not figure it out, for me it was the headlight fuse, it had blown but had refused itself and was allowing right headlight to go but left light only dim.

Only on a yaris does the headlight fuse blow, but still goes enough for you to get home hahaha. Classic built in toyota failsafe??

[sh0rtlife]

sorry i poofed..blew a water main to the house..so ive been busy with that..fun shit! but atleast i grew up as slave labour for dads const company so i knew what i was doing..and now the trucks slowly losing its heater core and the yairs threw another crank sensor and the "new" cv is failing fast

glad you got it sorted out

[RMcG]

Epilogue: The headlight bulb seems to still be working fine. And I bought a cheap magnetic pickup tool from Advance Autoparts and found the missing
10 mm socket. This pickup tool is cheap, because it is not flexible and it is not that long, but it worked for me.

I mentioned that I would post information on how I tested the relays. I did the testing by referring to this video:
How To Test a Relay (and How Relays Work) - in 8 minutes and I used the
12 volt Schumacher jump starter I mentioned earlier in post #6 to "bench test" the relays. There were two types of relays, both Denso. One type
was much larger than the other. I used the information in this video to identify the contacts in the large relay. And I as well as other info I got off
the internet, see attached images.

Thanks again to everybody especially sh0rtlife, but also bronsin and komichal and Compeer.

R.

[Theviking34972]

hi. just joined after finding your post on google regarding this issue, i now wish i had read the post before attempting to replace the passenger bulb as i have now blown all the lights (front and back) except the side lights i believe after putting the connection back on blinded. i often wonder why they make it so hard to replace a simple thing. so my question is now have i blown all the bulbs all will it be just the fuse ? and where is it located please ?