Hello, this could help, it happened on my 164 2L T.SPARK 1989 (no catalyst no clim).
just to say that I had a fail in engine cooling fan, it didn't start at more than 100°.
Lot of work to finally find that the ground (copper inside) wire (black) was totally worn *INSIDE* the electric sheath some 20 cm further the connection lug at the radiators thermo switch. It cannot be seen from outside.
fan wires
fan wires
164 3.0 V6 1988 330000KM
164 2.0 TS 1989 243000KM
164 SUPER 2.5 TD 1993 308000KM
156 1.8 TS 2001 165000KM.
EX : 33 SW 1.5, 1.3 ie, 1.5 ie, 33 1.7 QV 16V, GIULIETTA 116 1.6, ALFA 6 2.5 (X3), 146 boxer 1.6 , 164 SUPER 2.0 TS.
164 2.0 TS 1989 243000KM
164 SUPER 2.5 TD 1993 308000KM
156 1.8 TS 2001 165000KM.
EX : 33 SW 1.5, 1.3 ie, 1.5 ie, 33 1.7 QV 16V, GIULIETTA 116 1.6, ALFA 6 2.5 (X3), 146 boxer 1.6 , 164 SUPER 2.0 TS.