Jaguar Repair/1984 XJ6 Vandenplas Cigarette lighter
My Vandenplas has 2 cigarette lighters, one on front dash, the other in the rear console for rear passengers. The rear wasn't working so I pulled off the rear console and found the center positive wire disconnected. I hooked it up but it didn't help and now my front lighter doesn't work ! I looked for the fuse on the right side of the heater box, and found 2 in line fuses there. Bottom one kills my stereo if I pull it and the top one is only 5 amps and tested fine for zero ohms on a multimeter. So I'm not sure if it's the lighter fuse or not. There is also a 30 amp in line fuse in the transmission shifter console, it seems ok too. See picture - is that the right fuse for the lighter ? It has 2 brown wires with yellow strips coming into the bottom and a single yellow with brown stripe coming to the top.
ANSWER: Hi Steve,
Both lighters are powered by one wire from one fuse holder and that should be heavy brown wire in and either a brown wire out or a purple wire out to both lighters.
The heavy brown wire is hot all the time. and if the fuse and the wires are ok each lighter should have a purple wire on each that is hot all the time too. The small red w/blue tracer wires on the lighters are for lights only.
I learned that to find a fault in any electrical circuit you need to start at the "load" (lighters in this case) with either a 12v test light or a volt meter. Then follow the wiring diagram toward the source (battery). If necessary one joint connection at a time and you can not fail to find the problem.
Confirm that you have no power on the purple wire, then proceed to the area under the dash on the right side. Look for a fuse holder with a Brown wire in one end and a Purple wire out the other end. (It could have a Brown in and a Brown out and connect to a double connector and Purple wires further down toward the lighters.) Check all Purple wires for power and if you find one with no power, check between there and the lighter with your ohm meter to see if it is the correct wire and then continue on toward your battery power (There are two power posts in the firewall. One on the right and one on the left. I don't have info as to which one powers the brown wire for the lighters but I would guess it is the right one.
Lucas has a lot of faults but they are very consistent on their color codes and almost every British car uses a Brown or a Purple to power a lighter. So it is no use looking at other color wires unless someone has rewired it.
Look at one of your photos I sent back.
Let me know.
---------- FOLLOW-UP ----------
The power wire to the rear lighter is purple as you mentioned but I need to take the console between the front seats more apart to trace it since it goes into a harness wrapped in tape so I can't see the colors. The fuse on the right side of the heater box with brown in and brown out feeds under the trans shifter and terminates in a relay that kills the stereo if disconnected. There are also lots of plastic connectors that look like fuse holders but are just butt connectors. There are a few splices in there from previous 'repairs' mostly to power the stereo I think. I updated the stereo after Christmas with what I thought were stock wires for accessory and battery power but I think now they were added by a stereo shop. I'll spend some more time with it and let you know. Thanks again for all your help.
Steve, you still didn't tell me if you have power at either or both purple wires at the lighters.
I wouldn't open the harness unless you have power on one lighter and not the other. If you have no power on either wire I would go up under the right side pannel and look for and prob all purple wires for power. If you find several and any are dead use your prob and a ohm meter to see if that is the wire to both lighters. (most purple wires are powered with the key off on most any British car.)