PDA

View Full Version : Intermittent brake and wiper motor problem



combatmedic
12-09-2016, 06:28 PM
1990 Super Coupe,
Problem: started out as accumulator pump and wiper motor would intermittently stop working also getting parasitic draw of almost .5 amps. Isolated the draw to be fuel pump motor circuit by simply removing fuse in high current box under hood. The wiper and abs pump problem happened a few times but now not working at all. I have run test on all circuits/relays/fuses and I believe I have Isolated this issue to ignition switch. Because....when I turn key all the back, wipers work, accumulator pump kicks on. Turn key forward to on position or run, and they don't.

Question #1 does anyone concur with my findings and if so can switch be rehabbed or am I resigned to getting new switch.

Question #2 does anyone know where I can locate ignition switch wiring diagram?

KMT
12-09-2016, 06:53 PM
It may be as simple as spending less that $15 at autozone [ http://www.autozone.com/batteries-starting-and-charging/ignition-switch/duralast-ignition-switch/368100_0_0?checkfit=true ] for a new ignition switch...this isn't the traditional key cylinder switch, but a multi-connector switch that sits down on the right side of the steering column, activated by a rod, driven by turning the key cylinder. Takes a special security torx to remove, but otherwise a fairly straightforward task.

It's a very common point of failure on older SCs. Remove the two-piece plastic bezel around the steering wheel where it meets the dash and the kick panel, or, just try to look up and under to see if the current switch is opening up when you turn the key. Be careful if you remove the kick panel to not bust the pins that hold it in place...try to use a removal tool, etc.

http://contentinfo.autozone.com/znetcs/product-info/en/US/wl2/LS514/image/2/

Ken

TBirdJKC
12-09-2016, 08:20 PM
It's a very common point of failure on older SCs.

Ken

Common point is an understatement. All 7 of the birds/cougars I've owned in the past have needed the ignition switch replaced at one point or another due to the ceramic separating from the metal frame of the switch.

KMT
12-09-2016, 08:37 PM
All 7 of the birds/cougars I've owned in the past have needed the ignition switch replaced.

;)

How are they holding up? Done any of them again, since?

Mine was wonky when I got my Anny in 2008. Reminds me I've had some strange issues that might be related...pretty sure the one I bought has a lifetime warranty, so it might be time to wash/rinse/repeat.

combatmedic
12-09-2016, 09:29 PM
Just picked up new switch. Going to install tomorrow. Will post results.

TBirdJKC
12-10-2016, 12:23 AM
;)

How are they holding up? Done any of them again, since?

Mine was wonky when I got my Anny in 2008. Reminds me I've had some strange issues that might be related...pretty sure the one I bought has a lifetime warranty, so it might be time to wash/rinse/repeat.

Knock on wood. The newer plastic/metal design seems to hold up better. I've never had to change out more then one per car. I really think it's an aging/ambient temperature cycling issue more than a wear and tear problem with these.

I know exactly where to look when I start having weird electrical issues. From the radio not getting power to the ignition cutting in and out over bumps.

combatmedic
12-10-2016, 05:00 PM
New switch did not cure abs or wiper issue. Ready to procure a couple sticks of dynamite for an ultimate fix.

sam jones
12-10-2016, 05:34 PM
Good afternoon


The Electrical and Vacuum Troubleshooting Manual (EVTM) would be of great help. As KMT has stated many times check grounds. The Anti-Lock Brake System and Interval Wiper/Washer motor share Ground Bus 121 located in the drive side radiator support next to driver light assembly. Check for corrosion and or check condition of wire(s).



Good Luck.

combatmedic
12-16-2016, 04:12 PM
Thanks to all for the advice. Sam, thanks for pointing me in the right direction. Cleaned and remounted ground. Problem solved. Thanks

KMT
12-16-2016, 04:54 PM
Cleaned and remounted ground. Problem solved.

Which ones, exactly? Might be helpful to those w/intermittent ABS pump issues, thanks.

Also, did you check the one that runs from the pass. side motor mount over to the body?

Ken