Master Ace headlight high beams staying on?

[podunkvariant]

So this is an embarrassing question but without being able to find any information online I thought this forum would be the place to ask it.

I just was rejected for an inspection because the mechanic said my high beams were staying on regardless of whether the lights were switched to high or low. I looked at the lights when I got home, and when on high they are visibly brighter and pointing "higher" then when on low. All 4 headlamps stay on whether I am on high or low. This, according to the mechanic, should not be the case. He said only 2 of my 4 headlamps should be on when on low beam.

I am ashamed to say I never looked or noticed how many lamps are on when in low beam before.

Should there be 2 or 4? Is the mechanic correct? Thanks for indulging me.

[timsrv]

Here in the states our vans also have a 4 headlamp system. On low beam only the 2 outer headlights are on and the "beam" is directed down as to not blind oncoming traffic. When on high all 4 headlights are on and they light up everything. Of course I can only speak for the vans made for the USA market (we may have different rules than you).

I suppose it's possible your van has fog lights and perhaps the dash switch for them is on..........so check that. Tim

[podunkvariant]

Thanks Tim. That's helpful information, though not the answer that would have saved me some money! It's not the fog lights. I talked to another mechanic who thinks it could be the switch, though it would take some time for him to figure that our for sure.

The high beam indicator on the dash goes on and off normally, but somehow all the lights go on regardless. It's a mystery. I welcome any ideas from anyone who might have additional ideas.

[JDM VANMAN]

This could be way off topic but I know that in Canada the JDM vehicles that are imported get modified/rewired to have daytime running lights... any chance you have the same rules there and the van lights were rewired?

JDM

[podunkvariant]

VANMAN, appreciate your ideas. I don't believe that's the problem because I've owned the van for 2+ years and this issue seems to be fairly new. And up until now I've been using the same place to get my inspections done, so this is something that they've flagged for the first time as well. Thanks for reaching out and taking the time to help.

[originalkwyjibo]

This sounds like a ground issue in the headlight circuit causing current from the lowbeam side to feedback into the highbeam side of the dual filament bulb in search of a ground path. This would in turn energize the highbeam bulb as well. They will usually both be dim when this happens. Do your highbeam bulbs(the inner two lights)get brighter when the highbeams are switched on and the dash indicator is lit?

[Andywear]

Here's my van set up.

Lights on


brights on, "visibly brighter" & "point higher"


fog light button pushed


Looks like I only have 1 bulb that switches from low to high beams.

[podunkvariant]

This sounds like a ground issue in the headlight circuit causing current from the lowbeam side to feedback into the highbeam side of the dual filament bulb in search of a ground path. This would in turn energize the highbeam bulb as well. They will usually both be dim when this happens. Do your highbeam bulbs(the inner two lights)get brighter when the highbeams are switched on and the dash indicator is lit?

Thanks. Actually the inner 2 AND outer 2 get brighter when the highbeams are switched on. Does that still sound consistent with a ground issue? If so, I'd appreciate any tips on how I could try to diagnose that. Appreciate all who have replied so far.

[podunkvariant]

Hi everyone. I have done some troubleshooting today that I suspect will make my problem more obvious to the experts here (though I don't know enough to draw a conclusion from it). Here's what I did:

- separated the big blue connector under the steering column and checked all connections. They looked surprisingly perfect. No decay, burning, discoloration or anything. good as new. I reconnected the blue connector.
- pulled the RH headlight fuse and tried the headlights. On low beam both LH low and high beams were still on even when set on low beam. HERE'S THE SURPRISE...when switched to high beam the LH lights got brighter but the outer RH headlight also dimly turned on, though the RH fuse was pulled. re-inserted the RH fuse.
- pulled the LH headlight fuse and tried lights again. same thing in reverse, where on low both RH lights went on and on high beam the LH outer light also dimly lit up. reinserted the LH fuse.
- pulled the foglight fuse and tried again. No change except no fog lights.
- pulled the 40A fuse from behind the seat and inspected it and the fuse block. again, they looked pristine.

ALSO IMPORTANT...while doing all this and trying the headlights repeatedly on off on off, etc. the lights started to go completely off on their own sometime. Turning the switch back to off and then to on again often but not always made the lights come on again.

My high beam indicator light on the dash works correctly, fyi.

Does all this point to a bad switch in the steering column?? I appreciate any feedback, thanks a lot.

Marty

[JDM VANMAN]

I went to the search feature and typed in headlight relay and 33 threads came up that may have the answer or guide you in the right direction-

https://www.toyotavantech.com/forum/...archid=2936413

take a look at some of these threads and see if your finding the common similarities and post in that thread, hopefully this will help!!

Good luck and keep us posted

sorry that link doesn’t redirect you, please try typing in the search feature “headlight relay”

JDM

[podunkvariant]

Thanks VANMAN. I looked at several of those threads and was hopeful. I located the headlight relay and pulled it. There was no visible signs of corrosion or burning on the connections. I temporarily replaced the relay with an identical one from another part of the system and tried the lights again. No change from my previous situation. All 4 lights still on at all times.

I will point out that the headlight relay had been separately wired (not plugged straight into the fuse box) and cable tied to a red plastic box (for convenience I think the box and color are not relevant). So someone must have been in there at one time rewiring.

Maybe it's the switch in the steering column? Or someone else suggested a ground issue.

I can post to another thread as well, but that's an update and still welcome any ideas.

[originalkwyjibo]

You could try running a jumper wire from the ground pin on the back of the headlight to a clean point on the body with the lights turned on to see if that makes a difference. It wouldn't hurt anything. Just be sure it's the right pin. If the wiring has been hacked at the relay there's no telling what might have been done without hands-on diagnostics.