First, check the rad. Was it ever replaced? If it is good, check the thermostat, Does it overheat at idle? or on the road? At idle, most likely the Rad. On the road, could still be the rad. or possible the thermostat. Also, was the water pump ever replaced. That will also cause overheating. As time goes on, the impeller wears, and will not push the water fast enough. Good luck.
According to my Chilton's Auto Repair Manual : For a 1989 Mercury Topaz ( front wheel drive ) ( 15.9 US. gallons )
The 1989 Mercury Topaz has a curb weight of 1,183 kilograms. This translates into an Imperial Weight of 2,608 pounds.
1 - 3 - 4 - 2 ( for the 2.3 liter 4 cylinder in a 1989 Mercury Topaz ) The distributor rotar turns CLOCKWISE
185 - 70 r - 14
It's in the gas tank.
Its on the bottom of the oil pan.
Activating your four-way flashers on a 1989 Mercury Topaz is very easy. All you have to do is reach under your steering wheel and pull the only handle down there.
Have to take off the head, it's there.
On your 1989 MERCURY TOPAZ, the BACK-UP LIGHT SWITCH is: UNDER HOOD, DRIVER SIDE, LOWER ENGINE AREA, MOUNTED ON TOP OF TRANSMISSION
where is the fuel reset swith for a 1989 mercury topaz
25 to 35 watts
Mine's located on the passinger side at the firewall.