Howdy folks.

Today was my first day as an inspection tech at a local shop. They seem pretty up and up, and it was a pleasant surprise to me to start the day with an 80's volvo.
I found several problems with it, but there are two oddities I can't make heads or tails of. Also, it has ~450,000 miles on it, and I think this may explain one of the things.

1)It's an 87, but it has single-lens plastic headlight lenses like the 90-92 versions had.
2) There is no knock sensor pigtail at all that I can find. There's a knock sensor on the block that looks identical to the one on my 90 LH2.4 740 turbo, buuuuut there just isn't any wiring to it that I can see.

I can see that a knock sensor is on the wiring diagrams here: http://www.autoelectric.ru/auto/volvo/740/1989/740-89-13.gif so I believe it is intended to have a knock sensor.

This car (still) has the "biodegradable" wiring harness, but I don't see how that's related, unless someone decided to be weird and eliminate the sensor.

My best guess is that 1) The owner put the lights in custom (I know that's difficult on 700's, no idea about 200's) and 2) This is not the original engine, and it's a slightly later model (88-89 maybe?) with an updated knock sensor, maybe in a different location.


Is there some other location for the knock sensor for LH2.2 compared to LH2.4?

Cheers!