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Electrical Testing fog light switch

  • Thread starter Thread starter Nightstang00
  • Start date Start date Aug 8, 2019

Nightstang00

Active Member
Mar 20, 2017
133
12
28
Aug 8, 2019
#1
  • Aug 8, 2019
  • #1
I have a 93 gt and I’m trying to test if the fog light switch is working correctly. The fog lights haven’t worked since I had the car, the harness plug was a little melted but still worked. I wanted install a relay and wire it to be able to run by it’s self.
First I would like to know how to test the switch outside of the car. Then while it’s plugged in to see if there are wires messed up. Nothing looks bad but I haven’t looked under the hood just behind the dash.
 

jrichker

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@Nightstang00

Use a Multimeter with the low Ohms ( Ω ) or continuity setting. With the switch in the ON position you should see the same reading as you get when you firmly hold the meter leads with the metal tips touching each other. With the switch in the OFF position you should see the same reading as you get when the meter lead tips are not touching anything.

The fog light circuit also runs through the steering column and the multifunction turn signal/wiper/high beam switch. Check the wiring for the multifunction turn signal/wiper/high beam switch wiring for melted plastic connector shells and heat damage for the wiring.

Saleen0679 was nice enough to dig this up for us awhile back: How to replace ignition switch on 1979-1993 Mustangs. The process to gain access to the multifunction turn signal/wiper/high beam switch wiring is the same as the ignition switch.

Replace a 1979-1993 Ignition Switch Assembly

Electrical gremlins can surface in any car. Let&#8217s face facts. The more options you have and the more wiring running through your car, the more something is bound to creep up.
www.mustangandfords.com

Pigtail wiring repair kits are available from the auto parts stores for most of the connectors. You just need to be smarter and more persistent than the person using the computer to look for the parts. Google is a great help there as long as you don't lookup a political candidate...
 

Nightstang00

Active Member
Mar 20, 2017
133
12
28
Aug 8, 2019
#3
  • Aug 8, 2019
  • #3
jrichker said:
@Nightstang00

Use a Multimeter with the low Ohms ( Ω ) or continuity setting. With the switch in the ON position you should see the same reading as you get when you firmly hold the meter leads with the metal tips touching each other. With the switch in the OFF position you should see the same reading as you get when the meter lead tips are not touching anything.

The fog light circuit also runs through the steering column and the multifunction turn signal/wiper/high beam switch. Check the wiring for the multifunction turn signal/wiper/high beam switch wiring for melted plastic connector shells and heat damage for the wiring.

Saleen0679 was nice enough to dig this up for us awhile back: How to replace ignition switch on 1979-1993 Mustangs. The process to gain access to the multifunction turn signal/wiper/high beam switch wiring is the same as the ignition switch.

Replace a 1979-1993 Ignition Switch Assembly

Electrical gremlins can surface in any car. Let&#8217s face facts. The more options you have and the more wiring running through your car, the more something is bound to creep up.
www.mustangandfords.com

Pigtail wiring repair kits are available from the auto parts stores for most of the connectors. You just need to be smarter and more persistent than the person using the computer to look for the parts. Google is a great help there as long as you don't lookup a political candidate...
Click to expand...
Ok thank you. I’m wiring a relay into the fog lights to take the load off and to run the fog lights eight the parking lights on.
 
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