[xj] Flickering lights

While waiting for my wife to come out of Macy’s last night, I was having a
cigarette, outside the car of course, and while admiring the Jag noticed
that all the lights had this slight flicker with the engine idling.

Interior lights as well, headlights don’t seem to do it.

I am running 80/100 halogens and my ammeter is still reading between 12 and
13 volts.

Alternator/voltage regulator going? Your advice appreciated as always.

Ron
1986 VDP===================================================
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This is interesting.

OK, I’m doubting an alternator problem because the headlights seem normal.
Surely an alternator output problem would reflect (tee hee hee) in the
headlights, no ?

Most, if not all, of the lamps are individually grounded so I think we can
rule out a grounding problem----unless all the grounds degraded at the same
time. Since all the other lights are flickering then the problem must be
well upstream in the voltage supply…before it branches off into different
legs.

My guess, then, is a problem at the headlight switch and/or connector. The
red/silver wire from the switch feeds all the running lamps, and the
red/orange wire supplies the panel lamps (is that what you meant by
“interior lights as well” ?)…give 'em a jiggle or two and see what
happens.

Just a wild idea…

Doug Dwyer
Longview, Washington USA

While waiting for my wife to come out of Macy’s last night, I was having a
cigarette, outside the car of course, and while admiring the Jag noticed
that all the lights had this slight flicker with the engine idling.

Interior lights as well, headlights don’t seem to do it.

I am running 80/100 halogens and my ammeter is still reading between 12
and----- Original Message -----
From: “Ron Reiss” Reron25@nyc.rr.com
13 volts.

Alternator/voltage regulator going? Your advice appreciated as always.

===================================================
The archives and FAQ will answer many queries on the XJ series…
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Ron, which Macys? What is your idle rpm? If 650 or more, I’d say your
alternator may have a regulator or diode problem – a check with an
oscilloscope on its output would show this, but I don’t know if this is
possible for you. Drive it over here. :]–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

Ron Reiss wrote:

While waiting for my wife to come out of Macy’s last night, I was having a
cigarette, outside the car of course, and while admiring the Jag noticed
that all the lights had this slight flicker with the engine idling.

Interior lights as well, headlights don’t seem to do it.

I am running 80/100 halogens and my ammeter is still reading between 12 and
13 volts.

Alternator/voltage regulator going? Your advice appreciated as always.

Ron
1986 VDP

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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Could be Doug, but don’t rely on the headlights not flickeering, because their
heavier filaments have a longer thermal time constant and won’t follow as fast
a power fluctuation as will the smaller lamps – geeky enough? :]–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

Doug Dwyer wrote:

This is interesting.

OK, I’m doubting an alternator problem because the headlights seem normal.
Surely an alternator output problem would reflect (tee hee hee) in the
headlights, no ?

Most, if not all, of the lamps are individually grounded so I think we can
rule out a grounding problem----unless all the grounds degraded at the same
time. Since all the other lights are flickering then the problem must be
well upstream in the voltage supply…before it branches off into different
legs.

My guess, then, is a problem at the headlight switch and/or connector. The
red/silver wire from the switch feeds all the running lamps, and the
red/orange wire supplies the panel lamps (is that what you meant by
“interior lights as well” ?)…give 'em a jiggle or two and see what
happens.

Just a wild idea…

Doug Dwyer
Longview, Washington USA

----- Original Message -----
From: “Ron Reiss” Reron25@nyc.rr.com

While waiting for my wife to come out of Macy’s last night, I was having a
cigarette, outside the car of course, and while admiring the Jag noticed
that all the lights had this slight flicker with the engine idling.

Interior lights as well, headlights don’t seem to do it.

I am running 80/100 halogens and my ammeter is still reading between 12
and
13 volts.

Alternator/voltage regulator going? Your advice appreciated as always.

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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Hello,

The headlights should be flickering too, is just that they are
too bright to notice.

I think is the alternator’s regulator, but first check the switch.
Since it is as easy as turning off the headlights and see if the
rest of the lights continue to flicker. Still, the regulator could
still be the culprit, because the flickering might stop now that
the electrical load of headlights is removed.

Therefore the question is, how bad is a flickering regulator? I
would not worry about it as long as it continues to charge the
battery and it does not interfere with the radio. Check for
over voltage just to make sure, you don’t want to fry your
electronics. Some service stores do charge system checks for
free it you had purchased or plan to purchase a battery from
them.

Full regulator troubleshooting procedure is in the ROM and
also in Hayes’ and depending on the alternator model, the
regulator might be available for less than 45 USD. It
worked for me (check the archives).

Good luck,

Carlos Robert
1982 XJ6 SIII------------------------------
Date: Thu, 11 Oct 2001 22:23:37 -0700
From: “Doug Dwyer” DWYERD@email.msn.com
Subject: Re: [xj] Flickering lights

This is interesting.

OK, I’m doubting an alternator problem because the headlights seem normal.
Surely an alternator output problem would reflect (tee hee hee) in the
headlights, no ?

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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I had this problem, too. Can’t say that I “fixed” it but I did make it go
away. However, on mine, the headlights did flicker. Everything flickered!
I suspected a failing diode in the alternator but did not see much ripple on
the o-scope. Hmmm…

By chance, I happened to install the sound system, which includes a 1 farad
capacitor in parallel with the battery.

The flicker is gone. My chief suspicion, since the flickering was in time
with the ignition pulses, is that some line in the ignition circuit had an
effect that I inadvertently filtered out.

I will add that I am quite pleased with the effect the large cap has had on
both the sound of the amp and on the car’s power as a whole.

Trey McCay> noticed

that all the lights had this slight flicker with the engine idling.

Interior lights as well, headlights don’t seem to do it.

I am running 80/100 halogens and my ammeter is still reading
between 12 and
13 volts.

Alternator/voltage regulator going? Your advice appreciated as always.

Ron
1986 VDP

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

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Trey, with a 1F cap, you can just charge it up overnight and drive all day
with the alt & batt disconnected! :]–
Alex
79xj6L SII (BRG + wires)
86xj6 SIII (Black)
61 Sprite MkII (Red)
Menlo Park, Calif.

Trey McCay wrote:

I had this problem, too. Can’t say that I “fixed” it but I did make it go
away. However, on mine, the headlights did flicker. Everything flickered!
I suspected a failing diode in the alternator but did not see much ripple on
the o-scope. Hmmm…

By chance, I happened to install the sound system, which includes a 1 farad
capacitor in parallel with the battery.

The flicker is gone. My chief suspicion, since the flickering was in time
with the ignition pulses, is that some line in the ignition circuit had an
effect that I inadvertently filtered out.

I will add that I am quite pleased with the effect the large cap has had on
both the sound of the amp and on the car’s power as a whole.

Trey McCay

noticed
that all the lights had this slight flicker with the engine idling.

Interior lights as well, headlights don’t seem to do it.

I am running 80/100 halogens and my ammeter is still reading
between 12 and
13 volts.

Alternator/voltage regulator going? Your advice appreciated as always.

Ron
1986 VDP

===================================================
The archives and FAQ will answer many queries on the XJ series…
FAQs: http://www.jag-lovers.org/xjlovers/xjfaq/index.html
Archives: http://www.jag-lovers.org/lists/search.html

To remove yourself from this list, go to http://www.jag-lovers.org/cgi-bin/majordomo.