Headlights refuse to retract, 1974 car with headlights that refuse to retract Options

[Jezibel]

Main lighting switch raises lamps, lights up, but pushing switch back in fails to lower the lights.

AI says 1) Check fuses for failed or faulty fuse; 2) check headlight relay on fuse-box backside; 3) check grounds; 4) check headlights switch for possible corrosion on contacts.

System was working fine last week. It just decided today to not lower the lamps.

I have a replacement main lighting switch on order, also several Bosch 5-pin relays, and all the fuses check out OK (no corrosion on fuse block contacts.

I lowered the headlights manually, using the motor-end knobs, per the protocol, but it irritates me to not be able to immediately fix this apparently quite common problem on my '74 1.8 liter.

Any helpful suggestions, other than the cited "4-most likely causes' AI pointed out, above?

Thanks in advance.

[emerygt350]

Main lighting switch raises lamps, lights up, but pushing switch back in fails to lower the lights.

AI says 1) Check fuses for failed or faulty fuse; 2) check headlight relay on fuse-box backside; 3) check grounds; 4) check headlights switch for possible corrosion on contacts.

System was working fine last week. It just decided today to not lower the lamps.

I have a replacement main lighting switch on order, also several Bosch 5-pin relays, and all the fuses check out OK (no corrosion on fuse block contacts.

I lowered the headlights manually, using the motor-end knobs, per the protocol, but it irritates me to not be able to immediately fix this apparently quite common problem on my '74 1.8 liter.

Any helpful suggestions, other than the cited "4-most likely causes' AI pointed out, above?

Thanks in advance.

Did you check the relays on the headlamp assemblies in the frunk?

[Jezibel]

No, I did not. Where are they located in the frunk? The only relays I am familiar with are those on the underside of the fuse panel. Thanks.

[Jezibel]

No, I did not. Where are they located in the frunk? The only relays I am familiar with are those on the underside of the fuse panel. Thanks.

Below iz what AI sez:

What's NOT in the frunk: The main dimmer/combination relay (which switches the headlights on/high-low beam) lives under the dash, on the back side of the fuse panel — right where you've been working, not up front. So the core headlight power circuit is a dash-area relay, not a frunk relay.

What IS in the frunk (near each headlight): The 914's pop-up headlight doors each have their own dedicated headlight motor control relay, and these are mounted up front near each headlight bucket/motor, not under the dash. Here's the logic: the dashboard switch doesn't drive the pop-up motors directly — it just sends "extend" and "retract" command signals up two wires to the front trunk area. At each headlight, a cam-operated switch on the motor mechanism reads the physical position of that headlight door and compares it to which command line is energized. If they disagree (say, switch says "up" but the headlight is still down), that local relay near the headlight motor energizes and runs the motor — pulling +12V through fuse S12 — until the door position matches the switch position, at which point the cam switch drops the relay out again.

So to directly answer it: yes, there are relays at the headlight assemblies themselves, but they're the motor-control relays for the pop-up doors, one per side. The relay that actually controls whether the headlight bulb is on, and whether it's high or low beam, is back at the dash-mounted fuse/relay panel you've already been dealing with.

This matters practically if you're troubleshooting: a "headlights won't pop up" complaint points you to the frunk relays near each motor, while a "headlights won't come on" or "stuck on high beam" complaint points you back to the dash-mounted combination relay behind that same fuse panel giving you access grief.