85fortheDrive

Last evening, I installed some new interior LED bulbs (Thanks Nicole!) As I drove the car this evening, I noticed that all of the new interior lights are fluttering. Not all-the-way-on-and-all-the-way-off, but more like on-full-dip-to-half-on. This turned out to be true for the digital clock light and my headlights as well. It seemed like there wasn't consistent power to these lamps.

The battery gauge needle seemed quite jumpy too, wavering as much as a quarter of an inch almost constantly.

Any ideas here?

Relay, relay, relay?

Thanks guys.

Alan

Well Tim,
If the headlights are flickering they could be the cause of all the rest... I'd suspect in order:

1st - Gounding problems with the headlights (most likely cause IMO...)

2nd - Headlight relay connections/grounding issues

3rd - Voltage regulation issue (alternator)

4th - Ignition switch connections

1 - Look in the HL pods for thre ground connections - clean the front ground points, test voltage on the bulb ground to solid chassis gnd point and the voltage on the Hi/Lo beam connections? if yu stay on high beam does the same thing happen?, do the interior lights still flicker with the HL off?

2) Clean the GP's above CE, clean the HL relay blades / swap relay?

3) Check the voltage at the jump post - is it stable

4) Does anything else "waver"? - how about AC blower fan, fogs instead of HL ? wiggle the switch in ignition position... any difference...?

Alan

85fortheDrive

Alan:

As always, many thanks for the suggestions. I've not had a chance to get back to the car yet, but thought I'd provide another possible clue or two:

I did notice that after I turned off the engine, the interior lights did not flutter.
I've replaced the front headlights with H4's within the past six weeks.

Is the voltage needle on the instrument panel supposed to waggle or should it stay pretty stable while the car is running?

Moochas gracias.
Tim

Alan

Tim the voltage should be quite stable @ about 13.5v with the car running except it may droop a little at idle - especially with lots of equipment on (HL etc) - it should not droop below 12v though. The voltage guage may not be reading an accurate value so use a multimeter to test for jump post voltage -but if the car voltmeter is bouncing around that's not good.

If there were no other symptoms it could be just an instrument grounding or connection issue - but you have other tell tales to focus on here first...

If its really stable with the car off and always bouncing around when running (esp. with the lights off) it suggests most likely an alternator/regulator issue.

Alan

85fortheDrive

Well methinks I figured this one out today, thanks to Alan. I disconnected the battery and then reviewed my "handiwork" from a couple of weeks ago in which I disabled the car alarm by jumpering Z1 and Z6. Turns out, my wire clasp wasn't very snug. So I fixed that, scrubbed the battery contacts, cleaned all the relay contacts (thanks for the paint can opener idea from another thread) and the lights didn't flicker no mo'.

Thanks a bunch!

Bill Ball

In my case, the cause of this and some other recent anomalies (intermitent speedo failure, stop lamp warnings staying lit) is the ignition switch. I jiggle it and all is better for a few days. I need to pop the pod out and replace the electrical portion of the ignition switch.

85fortheDrive

Sorry to camp out in your post here, Bill. Have fun pulling the pod. I hope that solves your flickering.

While you're at it, how about some nice LED lights in the instrument cluster?

Bill Ball

Good idea about the LEDs. Thanks, and no problem jumping in on the thread. I just wasn't sure I ever reported back on what I found. The switch is doing a slow death rattle.

carguyhere2

Any luck yet??

928 Head lights shut off when I hit the brakes??? And lost my cruise control

I have a 1988 928S4 5 spd.

Very strange,

When the car is not running, my headlights work fine, and hit the brakes, nothing, no problem at all.

But when I start it, and/or drive it, as soon as I hit the brakes the head lights shut off. I do hear a vacuum click inside, that seems to be operating the middle air conditioning vent.
Have any clue??

And my cruise no longer works (worked the same day before I had the head light problems)

Look forward to hearing from you, Thanks in advance

Bill Ball

Sorry I did not get back to this easlier...

The headlight flickering and the subsequent sporadic speedo and stop lamp warning were all due to a worn electrical portion of the ignition switch. I finally discovered that wiggling the key, not re-seating the headlamp relay, was solving the problem temporarily. So, I replaced the electrical portion of the switch and all is better.

I'm not sure about your brake/headlight issue. Hopefully you have gotten help or someone that is good at this stuff will jump in.