when the dash is hot, our lights blink 17 times, but if the car is cold, this won't happen. doesn't matter if fan setting is 0 in any case.

everything functions great unless it is very hot (100+) then the fan operation is somewhat dicey and indicator lights in the instrument panel can twinkle and twitch, making me very nervous. the blower was replaced three years ago, but not the resistor. lots of codes are set but I don't trust that they really indicate the source. I could list them if that was helpful, but you've probably seen the list before.

temp sensors were replaced in 04 as well (near grab handles). how should I diagnose this? why don't the lights blink all the time? why does heat seem to make a difference? could this be related to my other issue - knock sensor signal absent or faulty (4-3-3)?

car is a 94 turbo wagon w/ECC and 150k.

thanks
matt

The lights on my 1998 do that on cold days! You have a vent/flapper that is not responding rapidly enough when hot, that's all. But, the ECC will not go into automatic mode as long as the lights blink right after start up.
Those codes in B-1 do mean something. They tell you what the problems are. Try erasing them, then post back with the numbers - I have definitions if needed.

Your knock sensor is totally different. They are known to slowly degrade over time/miles. Blame the wiring, it gets pretty hot up against the block. Replacing them is no fun, at least 5 hours of DIY, but you can then also replace the oil breather box and lines at the same time.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

Does system do a self-check on start up?

Matt

All Volvo ECC systems do it at start up. That is why you hear the compressor kick in/out even when it is cold.

I reccomend never setting the fan speed to zero, or off. You need fresh air in the cabin.

Klaus
--
The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)