Open ground somewhere? Bad switch? - Mustang Evolution

Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 1979-1995 Mustang GT



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 01-29-2014, 05:32 PM   #1
Registered Member
Regular
 
Join Date: Dec 2013
Location: mt airy
Region: North Carolina
Posts: 29
Open ground somewhere? Bad switch?

I've got an 88 gt and for some reason my wipers will not cut off unless I pull the fuse. What could it be? A bad switch? Maybe and open ground somewhere?
sawyers_15 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-29-2014, 06:22 PM   #2
Registered Member
Regular
 
ALMOST STOCK's Avatar
 
Join Date: Jul 2012
Location: Prunedale
Region: California
Posts: 366
If it's not stopping without pulling the fuse it could be the motor, switch, wiring or governor.
This from the 89 Mustang EVTM which is the same as the 88 Mustang EVTM.

INTERVAL WIPER WASHER CIRCUIT WORKS
1989 EVTM



HOW THE CIRCUIT WORKS
The Interval Wiper/Washer allows the driver to select LO speed, HI speed or Interval wipe. With the wipers in the interval position, wipes are spaced two to ten seconds apart.
The Interval Wiper/Washer Switch has a momentary Washer Switch, a four-position Wiper Switch and a Variable Resistor which sets interval time.

Washer Operation
Pushing the wiper/washer control knob sends current from Fuse 2 through the Washer Switch to the Washer Pump.

LO/HI Speed Wiper Operation
When the Wiper Switch is in the LO or HI position, section A of the Wiper Switch powers the interval override input so that the Electronic Switch and the Governor Relay are pulled in continuously. Wiper Motor current then flows through Fuse 2 and the energized Governor Relay contacts to the L terminal of the Wiper Motor. Power is applied to the H terminal of the Wiper Motor through section B of the Wiper Switch for HI speed operation.

Interval Wiper Operation
During interval operation, the wipers makes single wipes at lo speed separated by a variable length pause.
When first switched to INT position, section A of the Wiper Switch activates the Interval Timer. The Interval Timer momentarily closes the Electronic Switch, energizing the Governor Relay. Current flows to the wiper motor L terminal through the contacts of the energized Governor Relay. Ground is connected to terminal C of the Wiper Motor.

As the wiper motor turns, the wiper motor switch changes from the grounded PARK position to the hot RUN position. Current now flows through the R wire. Run contact of the wiper motor switch and resets the interval timer, which opens the electronic switch. The current path continues through the de-energized governor relay contact to the L terminal of the wiper motor. Wiping continues to the completion of one wipe. The wiper motor switch returns to the PARK position contact, power is removed and the wiper motor stops. After a pause (controlled by the variable resistor) the interval timer pulls in the governor relay to start another wipe.

Braking takes place when the wiper motor switch moves to the PARK position. The wiper motor L terminal is grounded through the PARK contact of the wiper motor switch and the de-energized contact of the governor relay.
ALMOST STOCK is offline   Reply With Quote
Old 01-29-2014, 07:11 PM   #3
Registered Member
Regular
 
Join Date: Dec 2013
Location: mt airy
Region: North Carolina
Posts: 29
Thanks almost stock for the reply, that gives a little insight on exactly how they work. But I'm still not sure where to start. I know that an open ground would cause them to constantly run, but where could it be?
sawyers_15 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-29-2014, 07:30 PM   #4
Registered Member
Regular
 
ALMOST STOCK's Avatar
 
Join Date: Jul 2012
Location: Prunedale
Region: California
Posts: 366
This might be more helpful with the wiring and ground locations it's form the 1988 EVTM...
1988 EVTM

Start with page 0 find what your looking for and then go to the corresponding page or pages.

Probably page 83 and work from there.

Hopefully this helps you track down your problem.
ALMOST STOCK is offline   Reply With Quote
Old 01-29-2014, 07:35 PM   #5
Registered Member
Regular
 
danbb24's Avatar
 
Join Date: Jan 2014
Location: El Paso
Region: Texas
Posts: 20
Quote:
Originally Posted by sawyers_15 View Post
Thanks almost stock for the reply, that gives a little insight on exactly how they work. But I'm still not sure where to start. I know that an open ground would cause them to constantly run, but where could it be?
Actually, an open ground would cause the wipers to not operate. A voltage short to ground, meaning voltage finding a path to ground, would cause the wipers to run continuously. First thing, do a visual inspection of the wires that lead to the wiper motor. Check for wires rubbing on the body of the car. The wire that supplies power to the wiper motor can be exposed to a ground source. The entire body of the car is a ground source so look closely.
danbb24 is offline   Reply With Quote
Old 01-29-2014, 07:44 PM   #6
Registered Member
Regular
 
Join Date: Dec 2013
Location: mt airy
Region: North Carolina
Posts: 29
Ok thanks danbb24 that's a good starting point.
sawyers_15 is offline   Reply With Quote
Old 01-29-2014, 07:51 PM   #7
Registered Member
Regular
 
danbb24's Avatar
 
Join Date: Jan 2014
Location: El Paso
Region: Texas
Posts: 20
No problem

Sent from my SCH-I535 using Mustang Evolution mobile app
danbb24 is offline   Reply With Quote
Old 01-29-2014, 09:03 PM   #8
Registered Member
Regular
 
89GTstanger's Avatar
 
Join Date: Jan 2014
Location: parsons
Region: Tennessee
Posts: 267
I would test the motor using an ohms meter. Use Google to find out what the ohms on the wiper motor should be and the test points. If its not correct and you need another one, take your meter with you and test the new one to make sure its good. I do that with my electrical parts. You'd be surprised at how many new parts are already bad.
__________________
You can't lose if you put God first!

1989 LX, 306 with TF top end kit, Anderson N-21 cam, TKO 600 trans with steel splatter shield,full Maximum Motorsports Mustang maximum Grip box, Detroit locker rear end with 31 spline Moser axles. Staggered wheels with Nitto 555 315/35/17 out back.
89GTstanger is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 1979-1995 Mustang GT

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Open headers Bschmidty General Mustang Discussion 1 01-14-2014 12:43 PM
Check engine soon light came on? KamzGT Pre-2005 V6 Mustang 27 09-14-2013 05:33 PM
Useful Mustang Information - READ THIS FIRST! Trojan Horse 1979-1995 Mustang GT 24 11-19-2012 10:54 PM
Trunk Wont Pop Open CodyNelson 1996-2004 Mustang GT 1 01-24-2012 11:34 AM
Bad luck... Blackedout Pre-2005 V6 Mustang 20 07-29-2011 08:50 AM

» Like Us On Facebook



10:46 PM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.