High beams do not work

(Greg) #1

88 XJS with quad headlights

My low beams and parking lights all work fine. But no high beams.

Fuses in left side engine compartment look fine.

When pulling back left switch on steering column, I hear no click anywhere. Also, the switch stick does not click into another position, it only returns back. Is this how it works on the XJS, a toggle? Or does it have two positions (which would explain my issue-bad switch on steering column)

Not sure where to start otherwise. Thanks.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #2

The stalk switch is not supposed to stick in another position; it is a momentary contact switch. And it often fails by having the ground wire break. On my '83, I simply attached a new ground wire to the outside of the stalk with a strip of metal formed into a tiny screw clamp, located near the base so it was all hidden within the column cover.

If the stalk switch is working, your problem probably lies in the headlight relay itself. It’s a “locking relay” and it ain’t cheap. It should be simple enough to test to confirm whether or not it is working.

(Greg) #3

Thanks Kirby, good to know how the switch works. I’ll take apart column and look, luckily without airbags, pretty easy I guess?
And I take it high beams will work like low beams, with no key in ignition?

Is the relay under the dash by the fusebox? I saw no relays in engine compartment.

(David Jauch) #4

I assume it is identical to the XJ.
The flasher is a toggle. It will give ground to the coil of the dip/flasher relay. That is in a silver can in the engine bay on the XJ6; hella made it. It is about 2-3 times the size of a normal one.
What happens is that brown (from the light switch) powers blue to the relay (along with the parking lighting and so on, unrelated).
Blue and brown enter the relay. Blue is switched (latching) to blue/white (high) or blue/red (low).
If blue is not powered then all the lights flash when you pull the stalk. Not sure why it won’t latch in this case, maybe it does.
I believe the stalk grounds the relay coil: from brown to stalk - ground.
The system is always hot.

TL;DR/Simple analysis: If there is neither click nor flash the ground wire to stalk is the first choice, but also check for power at brown to relay and if you can actuate it by grounding.
If it is stuck you can carefully open it. Inside the can the relay frame is hot, so better disconnect power.

Column probably easy, but not my first choice. Probably not needed for access… just the casing? Careful about the hazard if it is still in that dumb position behind the stalk.

Update: Ditched my glass fuse box for fused relays and can confirm everything. The stalk cable is blue with a black tracer.

(Kirbert - author of the Book, former owner of an '83 XJ-S H.E.) #5

Yes, but note: On my '83 the headlight switch had four positions: Off, Parking lights, Headlights, and Fog Lights. In the Fog Lights position, the high beams would not work! This is because in most states in the US, it is illegal to have more than four headlights, and since my '83 came with the four round headlights, the high beams had to be disabled to operate the fog lights. And the car HAD fog lights – but the power from the headlight switch went to the REAR of the car, and the fog lights didn’t work. In the UK “fog lights” are at the rear, warning lights for others when you’re driving in fog.