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I have noticed recently on these dark mornings while warming up our '91 base that there is a rapid pulsing of all the lights (dash, dome, and headlights). It's only just noticeable, it's not enough to distract while driving but at stops, there it is! So I'm wondering if anyone else has experienced this or are there any ideas out there. Alternator? Voltage regulator?
 

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I have noticed recently on these dark mornings while warming up our '91 base that there is a rapid pulsing of all the lights (dash, dome, and headlights). It's only just noticeable, it's not enough to distract while driving but at stops, there it is! So I'm wondering if anyone else has experienced this or are there any ideas out there. Alternator? Voltage regulator?
Is that pulsing related to the engine RPM? Do the lights get brighter if you step on the throttle?

A worn down or just plain too small battery can supply a little less current than the alternator gives when you step on the throttle. In other words, the available power when the car is idling is a little less than when you rev-up the engine. Just for testing, hook up another battery as if you were jump starting the car. See if the same effect occurs when you've got that extra power going in.

As you're about it, check the battery terminals for wear. Replace them as necessary, it's cheap anyway and I've never liked the lead terminals as the lead always seems to stretch a bit and becomes loose over time.
 

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Discussion Starter #3
Thank you for responding Mr. Architect, the pulsing remains constant and unchanging through the rpm range and the lights do not brighten or dim at idle or with increased rpm's. The pulsing condition is not constant, at other times I notice that it is not doing it at all. It also doesn't seem to matter if the engine is warm or cold. With 190,000 miles on our bambino I'm afraid all the electrical components are wearing out together. I will check on the battery condition as you suggested and maybe the voltage regulator as well. Happy motoring!
 

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I'm afraid all the electrical components are wearing out together. I will check on the battery condition as you suggested and maybe the voltage regulator as well. Happy motoring!
My 164 is actually a bit older than myself. It just doesn't have as many kilometres as yours.

If there was only one source of light pulsing I'd suggest you might had a corroded or otherwise faulty ground on that circuit. But then it seems you've got several circuits with that issue and they might not be on the same ground, I haven't checked that.

Do you have a cardisk? You owe yourself one if you don't...

Being an intermittent problem just makes it more difficult to diagnose. You say sometimes it happens, sometimes it doesn't. Does moisture seem to play any part?

Wish I could help you more but It's just never happened to me. Good luck and happy motoring.
 

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Also important to check the ground connections as well as those at the battery.
You're not using those battery clamps with 2 bolts and the little plate to hold the cable are you ?????
 

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Also important to check the ground connections as well as those at the battery.
You're not using those battery clamps with 2 bolts and the little plate to hold the cable are you ?????
I did knew I had an issue with the battery and the clamps (bought the car with a suspected dying battery and worn lead clamps). Today I couldn't start it. Had to ask my sister to borrow her car to go to the supermarket to buy a battery and new clamps.

The new clamps I've got have a nice brass colour, but I suspect they're not brass at all. They do have the little plate with two bolts but for good practice, I soldered them. I hardly ever trust crimped connections at all.

The results?

Haven't properly tested the old battery but I feel a lot more secure with a new one. I've now got two old batteries in my garage and I've modified a UPS so I can connect it to outside batteries. I used it for the first time in a prolonged blackout in the winter to power the circulating pump on my wood fired central heating boiler. The new clamps, though cheap, will outlast and in my experience outperform the lead ones, as long as they are bolted and soldered.
 

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Oh, I forgot to tell you the slight flickering I had on my lights is gone. It was just what I suspected.
 
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