I should almost start a new thread on this, but it's a follow-on to my original problem and Art will be following this so I'm hoping for his thoughts.

I replaced the failed bulb sensor relay with a KAE (Kaehler, Germany) as they're about half the price of the genuine Volvo/Hella ones plus not many suppliers bother carrying the grossly expensive Volve ones anymore, including FCPEuro.

Since then, I've had nothing but aggravation with the KAE relay, two of them in fact (second one an exchange unit for the first). Both intermittently misbehaved in the same way, turning the warning light on for 1-3 mins for no good reason then going out. I swapped both of them into two different cars -similar misbehaviour. Swapped in a known good Volvo relay -no problem in either car. I've done the usual bulb/socket cleaning/greasing in both cars and swapping bulbs left right. Both cars have stock lighting and I try to match brands left/right whenever possible, especially the headlamps.

Anyone else had problems with these KAE bulb sensors? The are very few reviews, but none indicate such problems.

I thought KAE stuff was pretty good, although my local Volvo indie guru feels otherwise and won't touch them anymore. I always used to go with the KAE 240 fuel pump relays, in fact I much preferred them over the Volvo/Striebel (higher amp rating can better handle the increased draw of worn pumps).

I'm at the stage of thinking the KAE design is simply too sensitive for my lighting and charging circuits. It may also just be a bad batch as the second relay came from the same supplier just a week later. KAE in Germany doesn't seem to offer customer support, leastwise not on their English pages, nor does my supplier and they're not keen to replace the unit a second time.

It's inconsistent which lighting circuit irritates them. In one car, it only seems irritated when the headlamps are on -momentarily turning off the headlights resets the indicator for at least 15 mins. In the other car, it's much more irritable and I've yet to identify a pattern -momentarily switching off the headlights, park lights or touching the brakes usually resets it for a few minutes. The second KAE was initially less sensitive than the first, but the sensitivity seems to be increasing with age, initially one false indication every few trips, now multiple times every trip.

Any thoughts Art, others? An errant capacitor, resistor or semiconductor perhaps?

I've yet to open it up. Before I throw it in the back of a box and put in my bridged sensor, I may give it a re-solder just for the heck of it to make myself feel useful.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now