I replaced my glow plug controller relay on my 87 wagon with the 95 version, also installed the coolant sensor and afterglow rated glow plugs, works great, no stumble or rough running irregardless of outside air temp. Just started the car here in CO. , temp 15F, smooth as silk. Much better result than the purple wire, up to 180 seconds of afterglow when needed.
Bought the relay from Potomic for $30.00, the coolant sensor from the dealer. Takes maybe 30 min. not including the glow plug change. Good luck.