Hi all

I have a problem where my retractable headlights won't stop going down when the headlights are turned on using the lighting switch.

So, I turn on the headlights, they pop up but then go down again, then they pop up and again and then down again, and around and around it goes.

The only way I can keep the headlights up with the lights on is by toggling the headlight retractor switch.

I checked all the fuses for the lighting system and cleaned all the grounds but it didn't make any difference. I don't think its the relays because both headlights play up at the same time.

This problem has come and gone a couple of times in the passed after washing the engine, but this time the problem is here to stay.

I had a look at the circuit diagram; I am really tired and the diagram is beyond me, so I'm hoping someone can see what's going on.

Attached Images

	Lighting system circuit diagram (1).png (179.0 KB, 5 views)
	Lighting system circuit diagram (2).png (136.6 KB, 6 views)

To add more information, they stop going down when turning off the headlights but not turning off the park lights.

I'm thinking its perhaps the lighting switch. I'll play around with it. If I can be bothered I'll remove and strip it and see if there's something I can do.

No ideas here...have been busy with a hurricane this week.

__________________
Jamie
'92 Prelude Si, '01 Miata, '63 Suburban
Occasional mechanic on Alpina B10 3.5 #92
38 years continuous years with Preludes
Speed Demon Racing
Jamie on LinkedIn

Yeah the circuit diagram is beyond us.

Hopefully your cars are okay. If not, I know someone who may need a new light switch. LOL

I played around with the light switch by turning it on and off slowly, pushing the stick in and pulling it out while toggling the switch. It didn't make any difference.

My motivation to fix this problem is low.


I saw your hurricane in Florida on the news. Wow! It looked like Hiroshima!

All I can think of is that the rotary switch for the headlights keeps sending a signal to the headlight retractor relay to keep going, so it flaps the headlights back and forth. The retractor button overrides that, so pushing it tells the headlights to stay up, whether they're on or not. So it does sound like the headlight switch -- no surprise that it's discontinued, so your only option is to pull one from a wreck if you can find one. Or keep using the override switch.

We got lucky. The hurricane was supposed to hit the coast about 30 miles north of me...instead, it turned early and hit 150 miles south, so everyone down there got the Gulf of Mexico knocking on their front door, and I just had all the dead palm fronds blown out of the tree in my front yard. Dodged a bullet.

__________________
Jamie
'92 Prelude Si, '01 Miata, '63 Suburban
Occasional mechanic on Alpina B10 3.5 #92
38 years continuous years with Preludes
Speed Demon Racing
Jamie on LinkedIn

Nah that's not how it works. The signal is analog. The retractable headlight control unit senses electricity when a switch is toggled and changes the position of the headlights accordingly. Have a look at the wiring diagram. See how in the headlight retractor motors there is that circle thing that opens and closes two different circuits depending on the position of the headlights, and those circuits go back to the retractable headlight control unit. It's a bunch of logic gates.

The fact the problem happens with both headlights suggests the problem is at a single point rather than like both relays going bad at the same time or something. Maybe one of the circuits going back to the retractable headlight control unit is not opening when it should after the headlights go up to signal to the retractable headlight control unit or perhaps the problem is the retractable headlight control unit itself.

There is no troubleshooting guide in the shop manual for this symptom.

Now that I think about it, it can't be the light switch because when you turn on just the park lights, the headlights don't go up, and then when you turn off the headlights but keep the park lights on, they stay up.

I just remembered something. This problem happens when a headlight blows when the headlights are turned on. The retractable headlight control unit must sense the current being drawn from the globes?


I am glad to hear you got lucky and dodged a bullet.

I saw that you are retired USAF. I wonder how many F-22's the air force lost from a hurricane this time round. LOL

I never had any headlight problems when I had a 2d gen, so never dug into it that deeply. Happy the 4th gen just turns on the lights.

No F-22s lost this time around. The only base under the gun this time was here in Tampa -- tankers, and nothing had to stay behind.

__________________
Jamie
'92 Prelude Si, '01 Miata, '63 Suburban
Occasional mechanic on Alpina B10 3.5 #92
38 years continuous years with Preludes
Speed Demon Racing
Jamie on LinkedIn

I was just outside shooting a video of the problem and noticed that the headlights actually don't stay up when they are turned off but the park lights kept on. That's not normal, they should stay up when turning off the headlights but keeping the park lights on.

I tried to upload my video to multiple file sharing sites but they aren't working or there is something wrong with my internet connection.

So, my computer monitor shat itself and I got myself a soldering iron and some new Japanese capacitors are on their way from overseas.

The air conditioner in my Prelude has never worked since I got the car ten years ago. I think the control module has a problem which is common, as described here:

Compressor Control Unit Fix


I'm now wondering if the retractable headlight control unit has suffered the same fate.

From what I have seen online, the air conditioner compressor control unit is manufactured by Oki Electric Industry and the retractable headlight control unit is manufactured by either Mitsuba or Stanley, however, they use the same plug, so in a couple of weeks I'm going to pull the retractable headlight control unit out of the car, open it up and have a look at it.

I'll report back what I find.