Frt parking lamps and rear tail lights not working

Just this evening I got pulled over because none of my taillights or front parking lamps were working. The funny thing is I checked this just a week or so ago and everything was fine then.
This is a 1994 XJ6 with the battery in the trunk. The headlights work fine as well as the brake lights and reverse lamps. Also the hazard lamps work.
So if I turn on the four way flashers, the various front and rear running lamps do indeed flash.
I looked for a fuse that would control all of these but I did not see a master fuse for the running lights.
I did some research and found a mention of the DBC10009 light control relay so I was able to unplug that and then replug it a couple of times just now but no change in the car’s condition.

Still no working running lights.
Suggestions would be most welcome since this is my only car right now.

Are you saying that when you turn on the hazards the side and rear lights are flashing, or your turn signals are?

Sorry, I think you are correct. When I activate the emergency flashers, it is the turn signal lamps that are flashing rather than the tail lamps and front parking lamps.

BTW, the cigar lighter and the power seats still function.


If fuse B2* in the left side fuse box is good, the common factor affecting only the side and tail lights is element H3 in the relay module H (the infamous DBC10009) in the yellow base under the passenger side dash (aka “the Auxilliary Sidelights Relay”)

*BTW, do the glove box and under-hood lights work?

AFAIK the '94 models had neither (no glove box, passenger air bag instead).

94’s don’t have under-hood lights either :slightly_frowning_face:

That’s very odd. The circuit diagrams I have for a '94 model’s electrics show both glove box and under-hood lights.Maybe they left them off in North America so that leaves DBC10009 Relay Module H as the prime suspect in Steven’s problem.

My 94 had both under bonnet and glove box lights. Prime suspect is as Bryan says the DBC10009 or ‘H’ relay box as it is sometimes called. The solder joints crack on the little board inside the box, an easy fix if you can use a soldering iron.

I have temporarily solved the problem by taking the DBC10009 relay out of the car, disassembling it from it’s case and “playing” with the relay contacts. The relay was remarkably clean inside with no corrosion or anything on the circuit board. I did this a couple of times and then re-installed the relay. It then worked upon installation and has mostly worked reliably since. However one time, this evening in fact, I got in the car and did not think the running lights turned on. I reached over under the passenger’s dash and tapped on the DBC10009 relay case and then the lights snapped on. So it is not 100% reliable but probably 75% - 85% reliable. So as a result I have been checking the state of the running lights before pulling away when I have to drive that car at night.

I have ordered a spare relay from a seller on ebay so I will have one just in case.

Have you dismissed Cassos’ suggestion to re-flow the solder joints on that relay? Fairly easy to do.

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Yeah, I’d do the reflow if I were you. Replacement modules are often suspect in the solder dept., just like yours. (and like the fuse boxes!)