Hi Guys. I have a 2003 Jaguar S-type. V-6. All components except brakes are stock. I followed the threads and also similar ones and am stuck. Both my low beams (I am assuming dip lights?) stopped working at the same time. My high beams work fine. My parking lights work fine. I checked all the fuses in under the hood and a couple in the interior pannel. All seem fine. I cannot find in the manual or online a single fuse that controls both lights. It seems they split the curcuits so that one is right and one is left. The manual shows Engine compartment R-10 HID lamp right side which I assume is the low beam / high beam relay and R-13 as the left side. Only problem is my R-10 does not have a relay in it. Could R 13 be controlling both? Could I be missing something? I did check the power at the lights and there is none for the low beam. I am assuming that is a relay issue just not sure which one as both lights don't work and no R-10 is in place.

Any help would be appreciated

 

Yes, I believe “dip lights” is the British term for low beams.

Wiring diagrams here:

JagRepair.com - Jaguar Repair Information Resource

Sorry, but I can’t play along right now. My tablet locks up with big PDF files. I think the HID and ordinary lights are on different diagrams, so make sure you pick the correct one.

However, before digging too deeply, when is the last time you saw both low beams illuminated? Your description sounds very similar to a coworker’s predicament one morning. He was in a panic and said both low beams were not working. He had to use his high beams to get to work.

He is a top-notch electrical troubleshooter but had convinced himself some common fault had killed both sides. Even more complicated than Jaguar, his car had separate control modules for each side. The only common point was the control switch. He was furiously trying to find one locally.

I asked when was the last time he’d seen both lights working. He poo-pooed the idea, but I finally convinced him to test the two lights individually. Sure enough, two bad bulbs. He’d been driving around with one low beam burned out, but never realized it until the second one failed and left him in the dark.

Is this story over yet?… I humbly present this heartwarming cautionary tale and suggest you test both bulbs before ordering any expensive parts.

 

Good one regarding the bulb-double-blow-out.

I guess a relay double failure is even less likely? If you have HID: R10 is relay for left HID light and R13 for right, see:
maybe check for corrosion on contacts and check the relays:
Diagram is printed on relay, 12V opens relay, and measure for continuity (multimeter) on switched contacts.
And you checked F14 and F34 in engine compartment fuse box AND in passenger compartment fuse box F9, F11, F23, F25?

 

THanks KR. I will check the bulbs as don't remember when the last was I saw them on. I think 2-3 weeks ago. What bothers me is not having 12v at the lights when the switch is turned on so don't think that is it but will double check.

 

Thanks Peter. I did check F14 & F34. Did check some of the fuses you noted in the passenger compartment but not all. Will also try that. I have no relay in R-10 and that bothers me as all the diagrams noted that it is supposed to have one. I swapped R-13 for a like one and no difference. I checked voltage at the light and don't seem to be getting any which makes me think a relay. Problem is I am not sure which one as previously noted there is not one in R10 and R-13 was swapped. Will check the bulbs too but don't think that is it due to not getting any voltage.

 

Or it could be some combination of faults. Maybe a bad bulb on one side, and a broken wire or failed relay on the other. The main gist is he could have been driving around with one low beam failed (reason unknown) for some time, and not realizing it until the other low beam failed.

Majog, does your car have regular halogen bulbs or is it HID? Big difference in troubleshooting, so we need to be sure. If HID, there will be a rectangular ballast on the outboard side of the headlight assembly. Here's an image stolen from eBay. The ballast is the flat silver box to the right of the picture:

 

Karl: Looks to be just regular halogen and not HID.

 

Groovy, making some progress. At the wiring diagrams linked above, you'll want to use figure 08.1. It's a pretty simple circuit.

No idea why you've got a relay installed at position R13 under the hood. Maybe somebody stuck it in an unused spot as a spare? Relays R10 and R13 are only used with the HID system.

For fuses, check F9 and F25 in the Primary Junction Box. This is the small box hidden inside the cabin, near the hinges for the right front door. I had my car for several years before even knowing this panel existed.

If those fuses check good, check for battery power on the brown/white wire at the bulb. Not 100% sure, but you may have to turn on the ignition to get power.

The grounds for the bulbs are switched on or off by the General Electronic Control Module, via the black/red wires. Not sure how best to test for that function, but I'd suggest checking for continuity between the terminals on the bulbs first, to make sure they are good.

 

Thanks Karl. I will check it later today and post my results. Have work now. Appreciate your help and suggestions. Is there a lowbeam or headlight relay for non-HID? I have my original user guide and everything looks to be HID related. Can't find anything on just regular non-HID lights.

 

Kinda, but not directly. Look at figure 01.6. Battery power to the previously mentioned fuses is controlled by two relays in the rear distribution box in the trunk:

Switched System Power Relay #1 (confusingly located at panel location R2) controls power to the right low beam and left high beam.

Switched System Power Relay #2 (panel location R11) controls power to the left low beam and right high beam.

Since you've mentioned both high beams are working, that tells us both relays are working properly. No need to mess with them.

 

Thanks! I have been looking at the schematics trying to find a common component. Will likely go through "All fuses" later today or over the weekend. Also will see if I can jump 12v to the lights directly and if they turn on. Both those are easily tried.

 

If you are going to connect 12V to the bulbs directly, make sure that those directly connected 12VDC cannot flow back into your harness (wiring loom).
Above you mentioned that you could not measure 12VDC arriving at the bulbs, I would not worry too much about that, as I do not trust any measurements in this area, as the signals there are utterly looney, as I had to find out, when trying to find a feed for my DTRL:
https://www.jaguarforums.com/forum/s...s-type-264128/

 

Thanks, Peter. I will do so. Planned on just jumpering the bulb to direct 12v with some pigtails once out of the car. Won't get to it today but will post later this week after I get a few minutes to check some of the things all you great guys posted.

 

Hey, what about me? Aren't you going to check the things I suggested?

 

Karl:

I definitely am. Was going to try yesterday but found out wife took the car for the day and did not get home until dark. Swamped at work today and expecting rain the next day or 2 so will likely have to wait until the weekend. I really do appreciate all the advice and will make use of the suggestions....

 

...if all else fails...

...I guess you could get inspiration from Tin Lizzy of how to design new low beams...
At least you could be sure that the low beam electrics are not going to fail...

 

Hey guys thanks for all the suggestions. So far I have found a wiring harness rats chewed through and 2 burned out bulbs. Had to order some as I wanted to go with LED and local shop only had regular H7 in stock. Will update once I get it all back together and repost.

 

Yep, that wiring loom definitely needs to go to a health spa...

Good idea about the LED bulbs. Hope you picked the right ones. The right ones are like a difference between day and night (compared to OE bulbs).
Also: It makes a massive difference to swap the T10 bulb in the front (those, which switch on after one click only of the light switch) - and again: if you pick the right ones - those are the right ones:
https://www.aliexpress.com/item/4000...672a1802ug7pC4

 

Karl are you a genius? Or can you just see the future?
I mean calling two burnt out bulbs was just brilliant!

12VDC is 12VDC there is no flowing back into the harness? You will have 12VDC EVERYWHERE in that wire and/or harness. That's how DC works?
.
.
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Guys: I just wanted to say thank you again for all the help. Got in my LED bulbs today and they went in without a hitch. I spliced the wiring harness and heat shrink wrapped them then wrapped the whole thing in electric tape just to make sure. Low and behold I have lights again I would have never though both bulbs would go out but be it the wiring harness issue or just that they went out different occasions, I will not know. But the advice that the easiest answer is usually the correct one is still damn good advice. Thanks so much for the wiring diagrams, ideas, and just spending your time helping a stranger!

j