No high beam indicator light

[archangel]

Hi all,

My 1990 Rev1 turbo failed its MOT because the high beam indicator light isn't activating. The actual high beams and flash all work fine. I thought it would just be a bulb replacement, but unfortunately it wasn't that easy. I checked the voltages on the indicator bulb contacts and when lights are off it measures 0v, when dipped headlights are on it shows 0.3v and when high beams or flash are activated it goes up to about 1.3v, though if I hold the flash the voltage creeps up slowly up to 2v or just above. I tested the voltage on the high beam pin on the connector to the dash and traced it to the connector under the steering column and verified those are also seeing the 1.3-2v
I've cleaned up the ground in the driver footwell are but no difference. Checked voltages on the right hand headlight bulb connector and it seems ok, about 12v on the 2 live wires on dipped and then the voltage reduces on one of the live wires when high beams are activated so that seems ok too.

Someone suggested it could be dodgy contacts in the headlight switch. Is this what the end of the headlight stalk connects to? And to get it out do I need to remove the steering boss, etc. to pull the assembly off?

Any help or suggestions would be very much appreciated.

[steven63]

mine did this after fitting LED headlight bulbs but dont know why, After refitting stock bulbs the warning light returns

[archangel]

My bro thought this might be the case. I also have LEDs but have replacement standard bulbs on the way so will install those and recheck. Hope it sorts it and thanks for the response.

[archangel]

Thanks again Steven. Have swapped bulbs back to standard H4 halogens and can confirm i'm now getting 12v on the high beam pin for the dashboard connector. Happy days. Now i just need to put the dash back together.

[shinny]

LED (or HID) bulbs will always stop the high beam tell-tale from working. That's because it draws it's current through the low beam filament (genuinely - check up the wiring diagram if you don't believe me - http://shinny.co.uk/toyota/MR2_SW_1993_ ... litusa.pdf) and the much high resistances of LED bulbs or switch circuitry of an H4 HID kit means that the dash bulb no longer "sees" enough voltage (potential divider... yada yada yada).

The easiest solution I came up with is to wire in two of those indicator load resistors (the ones that stop the fast blinking) in parallel with the low beam circuit. That works with the LED bulb I have in the dash; although I've never tried it with the stock filament tell-tale bulb, I strongly suspect it also works fine with that.

The other way I used previously involves cutting wiring under the steering column and some relays up in the frunk. I would no longer recommend that, given the method I describe above.

[archangel]

Thanks mate for the great suggestion. I decided i'm gonna make my life easy and just leave normal h4 bulbs in. So many other things to sort out on the car i can live with dull lights.

[Race Idiot]

I wonder, wouldn't something like this work?

https://www.ebay.co.uk/itm/2x-H4-LED-He ... SwrcxbiSJ4

Seeing as it's even got the correct H4 connector making it just plug and play?

I only ask because I ended up buying some raybring H4 LED bulbs which work brilliantly with the Raybrig housings. But I've never checked to see if the high beam light worked so it might be a bit of a snag come MOT time.

I did keep the sent of PIAA halogens that I had in there before but it would be nice if that just worked without having wire resistors in.