S2 xj6L no main beam headlights

XJ
1

Hi all,
I have been doing some work on my xj over the winter, replaced brske booster anf kower steering colunm among other things. Since putting eveything back together I have kost main bam on the head lights. I
I have trolled through the forums loojing for solutions and have check all connections fuses etc. I can get all four lights working if i switch the two wires on the relay, I have tried a twin relay set up that was intended for my MG with the same result of outer lights only.

I did see some info on how to check the switch (lever) but can’t find it now, anyone have any suggestions?
Pictures of ground wires on steering colunm and relay attached.

20200301_205509
20200301_2055092576×1932 1.63 MB

Thanks,
Dennis

2

On my Series 1 the lamps themselves ground via black wires on the leading edge of the inner guards, below the level of the lamps. I have found these to be at high resistance on more than one occasion. Expect a Series 2 will be similar? Paul

3

That would be my first check as well although OP says he can get them working by swapping the feed wires?

4

**
Your problem description is a bit unclear, Dennis
?


but the relay is a worthwhile starting point. A blue wire connects the light switch to relay #56; with the light switch ‘on’ - this powers either ‘high’ beam (outer and inners), relay #56a blue/white, or ‘low’ beams (outers only), relay #56b blue/red.

With light switch on; check for power on these wires/connections.

The relay has permanent power, brown wire to #81a - this provides switching power to the relay and ‘flash’ function; ‘high’ beam power when the stalk switch is pulled at any time.

A ground wire, black, is connected to relay 31b - grounded by the stalk switch when pulled.

The relay has a latch function alternating between ‘high’ and ‘low’ beam by stalk switch action.

The wires from the relay goes to 4 fuses on the fuse box; ‘low’ beam left outer + ‘low’ beam right outer + ‘high’ beam left, inner and outer, + ‘high’ beam right, inner and outer.

Remember that ‘all 4 lights working’ means that ‘high’ beam is powered - brown to 56a (blue/white wires|will do that. Actually proving that there is nothing wrong with the lamps or fuses. ‘Low’ beam (white/red) only works the outer lamps - but both ‘high’ and ‘low’ beams is to be powered from the light switch blue


Checkpoint for power at fuses, verifying that power is delivered properly through the relay


Without a more complete list of the work done it’s uncertain what has gone wrong. It may just be the infamous ‘fiddle factor’; while working in an area you have inadvertently touched tender points. Light switch connections springs to mind - but the first step is checking power at the relay for clues


The key is wire colours and connection points - the brown wire is always powered, to be treated with care, it is unfused
:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)
**

5

Thanks for your replies,
It seems I have power to the thick blue wire when lights switched on but not the brown one so I’ll go check that out first.
I rigged up a two

IMG_7662
IMG_76623024×4032 2.56 MB
relay set up borrowed from my MG that bypassed the brown wire with a red fused one striaght to the battery but still no main beams (picture).
I unplugged the firewall connections and had the steering colunm apart, but that was cleaned all seems to check out.
(Switching to my laptop as I see from my last post I can’t type on my tablet)
Dennis

6

Dennis,

as Frank wrote: your “is” situation is a bit unclear. With the main light switch on “Head” and the high beam stalk switch on “off” (ie no blue light in the cluster) what do you get? No light on outer headlights?

Then, with high beam stalk switch on “on” (ie blue cluster warning light on) what do you get? All four lights should be on, while the outer lights are on the high beam file.

If the latter one works, but the former doesn’t, my money would be on the fuses. Low beam outer headlights have separate fuses mounted on top of the radiator frame. Ground connections are prime suspects as well, as Paul wrote. While working under the steering column you also might have disturbed one of the two connectors between the light switch pin 4 and the head light relay pin 56.

Good luck, send more pics of the car and maybe use a full size keyboard;-)

Best

Jochen

75 XJ6L 4.2 auto (UK spec)

7

Hi Jochen,
With the main light switch fully on and main beam stalk off I do have outer dipped headlights.
When I pull the stalk nothing happens, no blue dash light or hi beams.
I switched the feeds at the relay and all lights come on including the blue dash hi beam indicator.
This indicates to me the fuses and grounds to the lights are OK plus I have cleaned the fuse holders and swapped out the fuses.
It looks like I don’t have power to the large brown unfused wire so i’m looking into that.
The steering column connections seem to all be in place, thanks for your patience I’m not an electrical whiz but I’m enjoying learning.
Pics attached
IMG_5302|640x480

IMG_2021
IMG_20213264×2448 2.72 MB

8

**
To clarify, Dennis; the stalk switch grounds the relay at each pull, alternating relay between high and low beam - there is no ‘off’ position. Secondly; the light switch ‘fully on’ m,ay be in the ‘fog’ position. In which case; the relay is disabled - preventing it from switching to high beam
so
?

Ensure that the light switch is in ‘head’ position - third step of the switch


Switching over blue/white (high beam) and blue/red (low beam) simply connects power (from wherever) to the high beam instead of the working ‘low’ beam. And since all this shows that power reaches the high and low beams when applied; there is nothing wrong at the lamps or the fuses


The brown wire must have power at all times. Correctly connected to the relay; it both operates the relay and powers the high beams in ‘flash’ function. If no power to brown you sure must look into that. As an aside; a brown is also connected to the main light switch - powering the headlamps (high and low) in normal operation


With the light switch ‘off’ - pulling the stalk switch should light up high beams


Frank
xj6 85 Sov Europe (UK/NZ)
**

9

Ok got it Frank,
Light switch is in head position, fog light switch is not enabled.
I’ll dive into the brown wire no power issue and let you know what I find.

Thanks,

Dennis

10

Aye, with no power on the brown, I don’t understand why anything lights up ?

At some risk. Jump 12 v to the brown and see if all things come alive.

The brown sources volts at one of the two posts on the bulkhead in the engine bay. just as fun, clean those terminals. Battery disconnected as you work .

Carl

11

Nice car, Dennis! I envy you if it’s a sand belt no rust car!

The outer headlights on on low beam sounds good. That means you have not interrupted the connection from the light switch pin 4 to the head light relay pin 56. The same is true for all lights on - exclude grounds and fuses from here.

No power on the brown wire at pin 81a is definitely wrong. There is a snap connector upstream and it might have come loose. Check out that the blue/black wire is connected well to pin 31b. This is the wire that is triggered by the stalk dip switch. Could be that your stalk switch is bad.

Good luck

Jochen

75 XJ6L 4.2 auto (UK spec)

12

OK I’ll give that a try,
I did disconnect a large bulk head wire and refit, I’ll start there.

13

Thanks Jochen,
I did buy the car from a semi desert area, Love working on it, driving it, polishing it
Going to keep improving as i go along as its a worthwhile car to keep nice.
Thanks for the good tips on the electrical issue.

Dennis

14

**
The lamps are fed power from the light switch, blue wire, Carl - the light switch also have a (‘different’) brown.

The brown on the relay normally operates the relay, as Jochen says - but powers high beams in the ‘flash’ function if the light switch is ‘off’ or ‘park’. It’s electrickery - one way of solving a dual function


Frank
xj6 85 Sov Europe (UK/NZ)
**

15

**
Without power on relay brown, Dennis - the relay won’t shift out of ‘last position’. However, relay itself may have failed, or being misconnected - or, as Jochen says; the stalk switch does not connect to ground


Frank
xj6 85 Sov Europe (UK/NZ)
**

16

I do have power to the plain blue wire, I checked the brown wire back as far as the connector under the plastic shroud on the left hand wing and have continuity but not checked back further yet. Someone said the brown wire should be permanently powered. If/when I get power back to the brown wire and if I still have problems is it worth pulling the cover back off the relay and try to manually operate it while its plugged into the loom? Or can the relay be bench tested? The connections to the relay were undisturbed prior to the problem so the connections should be correct. Plus I have been able to use the schematic in the manual to verify the connections.
I appriciate everones advice
 I know just enough electrical stuff to be dangerous.

17

**
All brown wires are permanently powered, Dennis - and they are unfused, ‘directly’ connected to the battery, so some care is required when manipulating them. If in doubt; disconnect the battery while browns are disconnected


Easy test; jumpwire between the powered blue(relay ‘56’) and brown (relay ‘81a’). This will supply power to the power to the missing brown power.

As a precaution, in case there is a loose brown end somewhere, the relay brown should be disconnected. Or at least; briefly touch the jump to the brown - if sparking; disconnect brown from relay
:slight_smile:

With both blue and brown connections powered; the system should work normally.

If not; there is no point in opening the relay - likely defective, it should be replaced. Bench testing is no better than tests done in-car - and it is easier in the car


If system works OK with the jump; restoring brown power is the obvious solution - eventually making a new permanent connection from a brown - like from the joining post at the firewall
? Disconnecting the original relay brown, of course


However; the idea that there is a loose/disconnected brown, somewhere, is a bit awkward


Frank
xj6 85 Sov Europe (UK/NZ)
**

18

Thanks
All the info has given me a good trouble shooting path
results to follow.

19

PROBLEM SOLVED!
The brown wire was was indeed the problem

OK I WAS THE PROBLEM!!!
When I was working around the brake booster I decided to clean up the firewall electrical contacts and wiring and I neatly tucked one of the brown wire up out of the way and only reconnected the other two of the three brown wires.
I traced the dead brown wire back from the relay which led to me finding the disconnected brown that Frank, et al, had advised should be powered continually.
On the plus side this exercise has taught me more about my cars electrical system.
My next project will be to do the headlight relay upgrade so the dipped headlight switch is via a relay.
Thanks everyone,
Dennis

20200305_193654
20200305_1936542576×1932 1.5 MB
20200305_193633
20200305_1936332576×1932 1.36 MB

20


?..

Frank
xj6 85 Sov Europe (UK/NZ)