1990 Mercury Sable Multiple electronic failure

KROISIN

MEMBER
1990 MERCURY SABLE
6 CYL
FWD
AUTOMATIC
10,000 MILES

My alternator failed, causing a voltage spike that destroyed my digital dash and EATC control. I keep blowing the # 5 fuse (electronic instrument cluster/EATC). Also, my multi function wiper/turn signal switch is not working. I was having issues w/it before the spike but now wipers don't work. (Only things that work is high beam, manually have to flash my turn signal, the washer pump works, and the turn signals work only if I have my foot on the brake. The other thing out is my rear defroster switch. My main thing tho is, even though I am going to get a new digital dash, EATC control, defrost switch, and replace the turn signal, what chances are that any of these will work? I am wondering as far as the dash and EATC goes, what else is going wrong? A short someplace? I am not going to replace anything until I find out if there is a root cause. Any ideas would be a great help. I am going nuts here!

1 Reply

MERLIN2021

MECHANIC
17,250 POSTS

5 - 15 Amp Electronic Cluster, Heated Rear Window Switch, Electronic Flasher, Back-Up Lights, Heated Oxygen Sensor (HO2S), Illuminated/Keyless Entry Module, Electronic Climate Control (1992), Brake Interlock Solenoid (1993-94), Eletronic Door Lock Control Processor (1994)
Unplug the connectors for each of these circuits, one at a time, plug them back in, when the fuse blows, you have the circuit located that needs to be traced and repaired.02 sensor, if it is blowing the fuse, replace it.