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Re: Shifter Quadrant / Nacelle Light

Posted: Tue Feb 19, 2019 11:36 pm
by Glyn Ruck
Jose ~ as I said in my first post "The resistor had multiple forms during production....." :)

Re: Shifter Quadrant / Nacelle Light

Posted: Tue Feb 19, 2019 11:41 pm
by Jose
so if that resistor goes kaput, no quadrant light?

Re: Shifter Quadrant / Nacelle Light

Posted: Tue Feb 19, 2019 11:42 pm
by Glyn Ruck
Yes ~ No quadrant light with the lights turned on if that resistor fails!

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 12:29 am
by Jose
so the question of HOW that quadrant light comes on, is resolved? That is, it NORMALLY COMES ON with the Lights Switch?

or does it come on with ignition/run during daylight hours? I'm still not sure.

I can do electrical mods, so if something needs to be rewired or "rethought" in the wiring harness, I can usually achieve it. What are fuses for?

A good example is the fact that American XJ-6 side marker lights do not flash or "blink" with the Turn Signals like they do in European or Australian XJ-6. I don't know about SA cars.

So I started experimenting and blowing fuses by the dozen until I made the Side Markers blink with the Turn signals in my XJ-6 and not one more blown fuse. It has been done to many American XJ-6 since I published the instructions in forums..
Safety First. The XJ-6 FRONT Turn Signals are buried in the front bumper. Can't be seen from the side.

Like I said, What are Fuses for?

here's a link to the video I made.This was a while back, probably 2003 or 2006.

http://jagupgrades.webstarts.com/blinki ... s_mod.html

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 12:40 am
by Glyn Ruck
In most cars the quadrant light/overdrive light etc. operates with the ignition on (you want a visual indication that the overdrive is operating during daylight hours. It is the same circuit). It is dimmed the minute the sidelights etc. are operated.

Fuses are to ensure that you don't overload the car's standard wiring. Draw too much current & any wire will overheat. You need something to protect that from happening hence a fuse of lower value than the wire that will blow sacrificially. Effectively disconnecting power from that circuit.

A car battery is capable of putting out huge current. It could fry every wire in the car with ease apart from it's own connector cables & the starter motor cable & it could make them hot enough to start a fire. The battery would likely explode if you shorted cables of that rating.

Heed my fuse value warnings earlier in the thread!

Not blowing fuses when you modify things could mean the fuse values are too high & you are placing the vehicle at risk.

Fuses are supposed to blow to protect the circuits in your vehicle. NEVER increase fuse values without OEM authorisation.

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 11:54 am
by Orlando St.R
Thanks, Glyn, for the extremely valuable info re fuses. Now I look, some suppliers do make it clear that they are continuous current rated, eg: https://www.autoelectricsupplies.co.uk/ ... tegory/243 and https://www.12voltplanet.co.uk/30mm-gla ... fuses.html.

I think that would explain a couple of times where, whilst working on the car, I would have expected a fuse to blow but it hasn't.

The Durite branded fuses seem to be most useful, since they display both the continuous current and blow ratings in the fuse: https://www.gsparkplug.com/durite-fuse- ... 74-35.html

EDIT: The Durite branded fuses I ordered, unlike the photo in the link above, actually do not have anything displayed inside the glass and only have a continuous rating imprinted on the metal end, which I doubt anyone would be able to read without a torch and a magnifying glass. :(

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 4:05 pm
by awiedie
Glyn, thanks for the heads up regarding the different type fuses. I'm off to the auto parts store for some 15A ones. And thanks for pointing out where the front door switches are - I just never stood on my head far enough.

Do you think that switch resistor is a replaceable part by pulling the circlip?
Glyn Ruck wrote: Tue Feb 19, 2019 11:28 pm Warning ~ Fuse values


Also remember that Lucas fuse values of 35 & 50 amp etc are old British 1 second blow standard.

Fuses you buy today unless you order specially are American Carry Current rating.

In modern fuse values you should select a fuse of approx half the value of the Lucas rating shown in Jaguar Manuals.

e.g. Lucas Horn fuse = 50 Amps. In modern US rated glass fuses you should fit 25 to 30 amp.

Failure to do this could cause a fire in our car's wiring in case of a short.

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 5:30 pm
by awiedie
Forget that last comment about pulling the circlip to remove the resistor, I can see now that the resistor appears to be held down with the terminal screws. There is a part number in the Lucas electrics book for the resistor, however - 54334020. Probably never find one though.

Now that I have located my front door plunge switch, I find that there must be a bad ground at the switch because the light now comes on but sometimes bright and sometimes dim and sometimes not at all. The switch/ wire connection is not accessible from inside the car. If you removed the nut at the plunger, could you withdraw the wire and switch back through the grommet hole in the side panel?

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 7:13 pm
by Jose
those switches always corrode inside, similar principle as the glovebox switch.

I have had good luck spraying WD40 or similar through the front of the switch and pushing and releasing it many times to clean the contact area.

you might find original door switches or you can also use the ones found in XJ- or any other car for that matter.

As far as I remember fixing mine, the door switches in the S type are screwed on to the metal, i.e., the door jamp metal is threaded. Release the nut and see if you can unscrew it out.

Re: Shifter Quadrant / Nacelle Light

Posted: Wed Feb 20, 2019 9:35 pm
by Glyn Ruck
Orlando St.R wrote: Wed Feb 20, 2019 11:54 am Thanks, Glyn, for the extremely valuable info re fuses. Now I look, some suppliers do make it clear that they are continuous current rated, eg: https://www.autoelectricsupplies.co.uk/ ... tegory/243 and https://www.12voltplanet.co.uk/30mm-gla ... fuses.html.

I think that would explain a couple of times where, whilst working on the car, I would have expected a fuse to blow but it hasn't.

The Durite branded fuses seem to be most useful, since they display both the continuous current and blow ratings in the fuse: https://www.gsparkplug.com/durite-fuse- ... 74-35.html
Yes ~ You don't want any 50amp continuous rating fuses in your Jag. :) You are lucky you have decent options in the UK. I got all my fuses from the UK.

Here you can only get US Rated stuff.