Electrical Testing fog light switch

Nightstang00

Active Member
Mar 20, 2017
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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.
 
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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.

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
36
@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.

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...
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.