The sensor in the rad only triggers the fan. The sensor in the manifold, the one on the right when you face the engine, is for the ECU, the one on the left, at the back on the head is for the dash, depending on the sensor and dash it shows either only overheat, or the actual temperature.
did the donor have a gauge?
the simplest course is to remove both senders from old engine similarly after a sender fails order for old engine a warning light for a sei needs a sender with a switch not temperature dependent resistor.
These posts could be the holding the answer. The temp light glowing dimly suggests it is getting a low voltage, rather than just being turned on. So it is expecting a temp switch, but its got a temp sender. Swapping the ones from the original engine seems like a good idea.
The fitted sensors are the Original ones that cam from with the 1.2 MPI engine.
It starts glowing first but it's bright after a while.
I think I'm gonna fit a gauge in that hole.
As the Sei has no tempature gauge.
As everything else work, fan and so one I guess nothing can go wrong... and it's just a fault.
The fitted sensors are the Original ones that cam from with the 1.2 MPI engine.
The used ECU came with the donor car
the fan switch and dash temp sensor do not go through the ecu, the rad switch goes through a relay and turns the fan on at a predetermied temperature and the warning light goes straight to the dash this too is set to come on at a set temp, the ECU only controls the running of the engine on the pre 2000 cars i have this set up on my car and it has run ok for 7 years and 60000 miles (only the temp sensor in the manifold goes to the ECU)