TA22 - Headlights Not Working Properly

**hks7mgt** · 07-10-2009, 11:26 PM

I been working on it for ages now and i'm stumped.

When the light switch is on parkers, all is good.

When the light switch is on lights (pulled all the way) none of the headlights are working. So i put the high-beams swtich on and only the far LHS light turns on.

I checked the earths from the battery to the block, from the block to the chassis, from the chassis/block to all the common plugs with earth wires (WB colour) in them and they all earth fine. I stuck my head under the dash and all the earths that i could reach earth'd fine.

The relay in the engine bay has been tested and i even swapped it for another and it seems to work fine. The plugs on the lights is getting power when the light switch is on...

I found the plug that switched the high-beam on, called Hs on the switch side in the wiring diagram (RW colour) and that has battery power 12V (not ACC) and when the light switch is on, it then goes down to 0.25V - 0.45V which varies as i adjust the dimmer. So that seems good...

Can there possible be a chance that all four of my light bulbs are blown? I think not as when i was first diagnosing the issue when the light switch was on (but no action) but with the high-beams switched on, all four lights were on but seemed dimmed. I'm yet to see that again thou

When i bought the car, the fuse for the tail lights was blown (but brake lights worked fine) and the radio is 'still' is not working. The radio was ACC power and all the earths are fine as well. I'm guessing the radio has died, so i'll need to swap it out to prove it.

I'm stumped!

I have the wiring loom with the 8 Fuses so there is no common earth at the light assembly as did the earlier wiring configuration. I can post wiring diagram if anyone requests it.

Any assistance would be greatly appreciated. Otherwise its off to the auto-electrician (but i wont be defeated dam it!)

**Invid** · 08-10-2009, 11:57 AM

You could try wiring up the lights temporarily to the battery or other more appropriate power source (with a fuse) to see if they work. Might eliminate one of the variables?

**"Z" UTE** · 10-10-2009, 08:29 PM

Sounds similar to a problem SillycarChick is having, dive over to the classic Celica thread and see how she is progressing. Maybe you can compare notes.

cheers Chuck

**RAAAH23** · 10-10-2009, 09:14 PM

hey mate

i just had exactly the same problem in my RA.

i was stumped aswell i handed it over the auto sparky and he worked his magic to fix it. my sparky found that the piece (dunno the name sorry) around the steering wheel with the whiper controls and light controls had sufferend from a short and the plug connecting this to the main fuse box/wiring loom had become melted resulting in a bad connection. there was also a second relay placed in for the head lights by a pervious owner was also f**king it up.all the dodgy wiring was reverted back to the original loom.

i dont know if that helps but might be somthing to look for..

**hks7mgt** · 11-10-2009, 08:48 AM

"Z" UTE - yeah i spoke to SillycarChick and her issue was slightly different and was a cause to a leaking earth, hence why i checked all my earths.

RAAAH23 - Thanks, i'll look into it. I did consider that the module thing-a-me-bob behind the steering wheel that controls the switching for the high-beams and indicators might also be causing the issue. The loom in this car seems to be untouched so a burned wire might be the cause here.

You give me an idea actually to use the 'diode' (beep) option on the multimeter and test for continuity (if that is the right term) thru all the wires on each plug under the steering column where all the wires pass thru from the dash and instrument cluster thru to the rest of the car.

**hks7mgt** · 11-10-2009, 10:41 PM

Yeah i fixed it. The issue was not a leaking earth or a faulty plug or a burnt wire or a bad light switch... it was me for not checking to see if ALL the four sealed headlights are actually blown! Who would have thought it - not me!

It now concerns me as to why all the front headlights all blew (except for the LHS highbeam element) but i have just aquired the car and it was been off the road for the best part of the last decade so i'm hoping nothing cause them to blow as they were just ready to die...

Moral of the story, make sure you have a spare car out the back for spare parts and don't assume the worst case scenario.

Thanks for all your suggestions too