I had the stalk replaced, and the dimmer switch replaced, and my brights stay on anytime the headlights are turned on. How can i test it myself to see if i have a defective relay, or other problem? Thanks, Sparky

 

When you pull back on the stalk does the high beam relay click? The relay is on the LH side of the engine bay, just forward of the master cylinder.

There's a blue/black wire at the relay. Remove it. Do the high beams go out?

Do you have a 12v test light? If so, configure it to check for ground. Is the blue/black wire always 'grounded'? Or does it alternate ground/neutral when the stalk is moved back and forth?

The relay is a 'latching' type and I suspect it is stuck. Or the blue/black wire is always grounded....which would keep the relay engaged

Cheers
DD

 

Its almost certainly the relay. People focus on the dimmer/flasher switch but its actually just a simple contact that sends an earth to the relay. All the complexity and latching between high and low beam is in the relay can.

To test pull the blue black wire off the relay.

Check that you see an earth on the wire only when you operate the high/low lever.

If that is the case , with the wire still off, then turn on the headlights. If its still on high then the relay is stuck.

Choices then are:

1. Replace with correct OEM relay
2. Replace with generic relay (I did this a while ago)
3. If you like a bit of a tinker, you can open the can and see if you can see whats wrong. It make just be two contacts stuck together.

- oops I see Doug has arrived while I was typing, follow what Doug says, you cant go wrong :-) He's in your time zone as well.

 

he said he replaced the stalk switch, why was it replaced?

 

Once in my misspent youth, just after I came to this part of the world, I had 100w high beams get stuck on in the Feather River Canyon. It was a Complete Disaster as I could Not dim for surprise oncoming traffic that appeared around all those curves. Too much current through the single relay had fused the points.

Solution: I found a wide spot, lifted the hood and bashed around under there in the general area of the relays until I hit one and the highs went out.

Right after that I learned 100w were not legal in California so when I put in 75w I also wired a relay for each fixture; 4 relays. Never had another moment of trouble. I sold the car with that setup several years later, Summer 2015.
(';')

 

Bless your heart. You must be the last person who cares about other drivers' eyes. Thank you.

In my neck o' the woods the courtesy of dimming lights is just an old memory. Not only do people not dim their lights but everyone and his brother has all these upgraded bulbs...and fog lights...and driving lights....all in use 24/7/365. Very annoying and inconsiderate. It's some sort of power trip thing.

I've outfitted many of my cars with high powered and/or additional lights...to be used *when needed*.

Cheers
DDD

 

Thank you, Doug,
If you've ever driven that stretch of highway 70 from Oroville to the junction with SR89 you're familiar with the vertical cliffs rising from the road on one side and a sheer drop-off a couple hundred feet to the Feather River on the other side of a 2 lane road that has more curves and twists than a malaria germ. (It's a Ton of fun in a Jag!)

I had the inside lane as I was coming West, so the other poor suckers had the drop-off into the drink if they missed a curve, guard rails notwithstanding! I was afraid I might kill someone that I had unintentionally blinded!

I don't like being blinded by inconsiderate drivers (I hate the blue bulbs most), so I sort of feel that consideration begins with me.
(';')

 

Ditto:


Road manners. Gone or going fast....


1. Way back when, my driving was on highways, two lanes only and in opposite directions. Texas! Operation of the 'dimmer switch" on the floor boards an essential part of night driving. Not only dim for oncoming cars, but on approaching a slower car from the rear. Two fold.
''I don't want to blind you via your mirror, and I'm going to pass".


2. Yes, I've added extra lights. Both "fog"' or '"driving" lights. Actually, more for looks than anything!!!


3. My daughter was planning a trip to the coast at night. she was concerned with the fog. Rightfully so. When I mentioned that using the 'brights" was counter productive, she was perplexed! Yes, the brights reflect back in to your eyes and do little to illuminate the road. Dim is better, actually the beam is just as bright, but aimed down.


She reported back that there was little or no fog and all was well.


4. CA has rules on what lights must be lit at night, supplemental ones or not.


Carl

 

Amazing that you paid someone to replace those parts to fix a problem and you still have the problem?

 

No diagnostics, mere tossing parts at it.


Carl

 

thanks for all the tips, so I found the problem, relay was wired with crossed wires, guess the pros I took it to couldn't follow a wiring schematic. Ordered a new relay, as this one is fried, just have low beams. I have another issue as I've worked on this, when my headlights are on, my gas guage pegs past full, some sort of feedback issue? now, where to start with that mess.

 

Comments:


1. With a name like yours, these things oughta be right up your alley!


2. The pro's". What a misnomer???


3. head light to gas guage back feed? Wowee, that is a strange thing.


As you refer to schematics. Do you have jaguar Publication S57? Even I, with limited electrical skills find it the best Iv ever encountered. I get it.


Does the tank selection switch change the reading from right tank to left tank and vice versa ? Or full, in each case, no matter what level the fuel is ?


As the stalk switch is on the ground leg of the light relay and the fuel level sensors are also ground driven. I sense a crossing of grounds.


Just a guess. A better process would be an exam of the aforementioned schematic to see where these paths might cross.


I punched the on button on one of my coolers a bit ago. NADA! Oh, ...
Odd, I turned the knob to select compressor on. The compressor energized. 1/2 function. So, I did a "Jaguar thing". on/off the button a couple of time. Yeah, fan on. So, I'm running the fan, but not the compressor. OK, now. early AM. Vent the house. Cause later, it will be shut down and AC on!!!


Odd, how things transcend.


Carl

 

To clarify, after installing a new, correctly-wired realy, you have only low beams? If so, check/clean the fuses at the headlight fuse box and bullet connectors nested below. And clean the headlight grounds on either side of the radiator...you'll see 'em with the hood open.

Almost certainly a poor ground as Carl mentioned.

As a stepping-off point......

The instrument panel has a metal backing with two ground tabs and wires (next to the speedometer and tachometer). Make sure the ground wires are secure...maybe consider adding a redundant ground.

A good practice on these old Jags, as you are performing various tasks here and there, is to clean and secure every ground wire/contact point to happen across. In so doing you'll preemptively solve most of the much ballyhooed "Lucas, Prince of Darkness" problems.

Cheers
DD

 

the two ground wires / connectors that Doug mentions are located:

one below the BATTERY gauge, at 5:00 pm position,

one below the TEMP gauge, at 7:00 pm position.