What are these warning lights?

I believe 83 QV has 2 cats, thus 2 slow down (overheat) lamps. 84-85's have single cat & one light (mine can't be trusted, light would come on with thermocouple disconnected)

 

No cats at all on a "stock" euro '85 308QV, so no cat overtemp warning light(s) (unless added during conversion).

I'd bet that even if they added a cat, most didn't get an overtemp warning system -- but just a feeling/guess...

(Larry's comments apply to US version 308QV).

 

Yep, my 83 has two cats. The lights come on when they overheat.
I've only had one bank light up once when a mechanic fouled up the distributor rebuild causing one bank not to fire. On the bright side, I know the lights work.

 

Larry,

When I bought my 85 308, my cat light was intermittant...even with the engine off. Thanks to a great brother who set me up with a 308 wiring schematic, I was able to figure out that the cat warning light system is pretty easy to diagnose, it has a thermo couple, a warning light, and a module with only 6 wires on it.

2 wires for the warning light,
2 wires for power,
2 wires for the thermocouple.

I found my thermocouple wires had been pinched by the modules mounting plate there in the trunk.

Look carefully for pinches, twists, or maybe even the cover mashing the wires together. That may fix your light.

Doug Crall

 

You should be able to tell by a visual examination. A typical cat is about 18" (0.5 m) long with flanges on both ends, and the central "body" of the cat will be larger than the general exhaust tubing size.
The "stock" '82-'85 308QV euro exhaust shape/layout is not particularly well-suited to easily adding a cat (or cats), and, with the dual-entry muffler design, it is somewhat more similar to the '83 US 308QV approach (but I believe you can't just "bolt-on" the US version stuff -- either the single or dual cat set-up). However, with a tubing bender and a welder, it wouldn't be that difficult to do a custom system so you could have anything.
I'll post some jpegs from the OMs and SPCs for reference.

 

The single-cat '84-'85 308QV US exhaust system (OM page 74):
Image Unavailable, Please Login

 

The single-cat '84-'85 308QV US exhaust system (from the SPC):
Image Unavailable, Please Login

 

The dual-cat '83 308QV US exhaust system (OM page 73):
Image Unavailable, Please Login

 

The dual-cat '83 308QV US exhaust system (from the SPC):
Image Unavailable, Please Login

 

The no-cat '82-'85 308QV euro (standard) exhaust system (from the SPC):
Image Unavailable, Please Login

 

A stock '84-'85 308QV US cat:
Image Unavailable, Please Login

 

A typical "aftermarket" '84-'85 US cat:
Image Unavailable, Please Login

 

It may, or it may not. Some cars got through US customs and entry without having cats added (I had one of those, and '84 Mondial QV). They were typically brought in a "collector" cars and were supposed to be driven limited miles. Over the years, and as cars changed hands, that dropped away and folks just registered them are regular cars. They only had a problem at inspection, but often snuck through because state inspectors were baffled by 'exotic' sports cars.

The only way to tell if you have them or not is to look. Steve did a nice job of showing the configurations and the differences. Pop the engine compartment bonnet and look down the rear of the engine, or lay down on the ground and look forward of the muffler/exhaust. Either the headers and down pipes run straight to the muffler unit, or you will see the cats (or one cat depending on set up). One or the other.