Testarossa Dash Light

You can do a search on the topic, as it has been widely discussed and is a very typical problem. Most likely the fault is due to a defective ECU that controls the operation of the 7-12 slow-down light. They have pretty much a 100% failure rate and were replaced by an updated unit (which will have green potting material instead of the original black material). The ECU's for the 1-6 and 7-12 slow down lights are located under a panel at the right side of the engine compartment. You can follow the wiring from the exhaust thermocouples to the ECU's to find them. You can test the ECU by swapping the the 7-12 unit for the 1-6 unit. If the fault follows the ECU, then you know that that is the culprit.

 

Hi Dave, congrats on the purchase of your car. Better to post specific questions about your testarossa in the Boxers/TR/M section. Your issue has been well documented and a PITA. Read this thread and then head over to the testarossa section to post more questions.

https://www.ferrarichat.com/forum/threads/slow-down-lights-coming-on-at-same-time-always.448200/
Cheers

 

The panel is the one just above the fuel pressure accumulator with the plastic clips for the main wiring harnesses, and has angled corners on the ends. Un-clip the harnesses from the plastic clips and you will see the two 6mm bolts (10mm heads) that hold the panel on. In your photos you can see the braided wires (with the yellow and red heat-shrink tubing on them, and masking tape) and connectors coming from the thermocouples in the exhaust going to the ECU's for the slow-down lights. Usually the connectors are hidden behind this panel, and you can only see the wiring from the thermocouples.
The panel that you removed has the two ECUs that control the fuel injection lambda systems.

The masking tape indicates that someone has already been in there investigating the issue. You don't want to mix things up as far as the correct thermocouple is providing information to illuminate the correct warning light 1-6 or 7-12