View Full Version : Need some electrical help!

Dustin Yenny
03-11-2003, 07:35 PM
I just purchased another 1989 SC from a member of the club. The car has some issues. The brake and anti-lock lights are on all the time and the pedal is hard. The PO replaced the accumulator and I replaced the brown pump relay. I believe I hear the relay clicking when I turn the key on but the pedal does not ease up. I went through the same exact thing with my first SC (a 1989) and it turned out to be the pressure switch. I haven't had time to check for power to the pump or ground pin 4 of the pressure switch connector but I'll do that later.

The car has some issues with the following accessories:

lighted visors
auto ride control
rear window defrost
blower fan (doesn't run)

I have checked all the fuses and everything is fine. Now this is where it gets tricky. The car sat for a year or so. I was backing the car up and down my driveway and for a split second the fan kicked on and the brake pedal eased up. I haven't been able to recreate this event since.

I'm hoping someone that has had a similar problem with these circuits can guide me in the right direction. My best guess is on a bad ground wire somewhere.

Thanks for any help!

03-11-2003, 07:48 PM
Check your fusible links, with that many things wrong I doubt it would be a ground since most have separate grounds (they all donít connect to the same ground point)


Dustin Yenny
03-11-2003, 07:53 PM
The fusible links are in the underhood power distribution box, right? I checked all those links and everything was fine. Damn, I was hoping there was a common ground somewhere.

03-11-2003, 07:57 PM
You know the fusible links can look just fine right? You checked them with a meter?


Dustin Yenny
03-11-2003, 08:02 PM
No, I didn't realize they can look fine and be bad. I have a digital multi-meter and an analog multi-meter. How would one go about testing the fusible links?

I'm heading out to go back to my house. I'll check for power to the radio/vmm and the other accessories.

03-11-2003, 08:29 PM
I had similar electrical problems and it ended up being the ignition switch, if the switch is loose or doesn't feel " RIGHT " change it.

03-11-2003, 08:31 PM
From where the connection begins there is +12V, check at the base of the link and again after the link. Usually the wire burns up and desinegrates so the link will feel like there isn't any wire in it. Sometimes it doesn't. Just probe the wire b4 and after.


Dustin Yenny
03-11-2003, 09:25 PM
You know you might have something there with the ignition switch. I could get the pump to kick on for a second by playing with the ignition switch the other day and it does have some play.....although the car seems to start and run fine! Fusible links are good. I guess I will try to replace the ignition switch....if that doesn't work I might have to invest in an electrical manual.....the factory Helms manual does not have any wiring diagrams.

03-11-2003, 09:42 PM
I bot the s/c cheap from an import shop who had replaced the head gaskets but couldn't get the fan to come on and still overheated. I spent a month diagnosing the thing, headlights worked some times , radio sometimes, fan never etc. etc. Went thru fusible links, relays, bot wiring diagrams, and then i decided to start from scratch and changed the entire steering column, from my good s/c ,and ALL my electrical prolems were solved. Because the multi-function switch could also be bad and cause some of your problems, don't freak out if all your problems aren't solved by the ignition switch. good luck

03-12-2003, 12:09 AM
Good call BARTHWY59.


Dustin Yenny
03-12-2003, 10:00 PM
Thanks guys! I replaced the ignition switch today with a Motorcraft replacement and everything is working again including the brakes. I feel like I stole the car now at the price I paid.

03-12-2003, 10:20 PM
my bill is in the mail. Congratulations..

03-13-2003, 01:13 AM
nice information have, this shoudl be in the FAQ section ;)

BARTHWY59, nice job :-D

03-13-2003, 01:33 AM
Dustin, the SC gods gave you a payback for your last Sc leaving you at the side of the road ( fuel pressure problem was'nt it ?) BTW what happened with that car ??
Good call Barthwy59

Dustin Yenny
03-13-2003, 08:53 AM
Actually, the 1991 left me beside the road twice in two days. I replaced the fuel pump and ended up dropping to tank the next day again to figure out why the car quit running. I sold that car to XR7 Dave after a small deer incident and I believe he did some work to it and it is currently for sale.

P.S. The deer incident happened the night that I finally got the car back together and running. I don't have very good luck!