fog lights - what's the deal?

[140cilx]

I ran a search and couldn't find an answer.

My fog lamps working 6 months ago, quit working about 3 months ago. Switch no longer lights up. I think I read somewhere a common failure on these, but cannot find it anymore.

The bulbs are fine, wiring is all there. Checked all fuses (fusebox) and they are fine.

Anyone know the problem and solution? I'd like to fix these permanently before the reunion. Thank you.

-140

[svobud]

think you answered that one yourself...the switch. Have you pulled it and checked it on a meter?

[140cilx]

no bud I haven't. Ok, I'll check it. If bad, where do I find a switch (besides Cane Lakose - sorry bad joke)?

Is there an improved suggested switch?

Thanks again.

[svono50]

Check with Paul @ SVPU (sounds like a broken record, doesn't it). I don't know of an improved one, but there are replacements that work. The problem with the circuit is that the full current of the fogs go through the switch and sometimes end up melting it (ask me how I know). I added a relay in my circuit under the center console, so far so good.

[svobud]

Originally posted by 140cilx


Is there an improved suggested switch?

I'll try to bring some to the Reunion. I've got spare parts that I've had for store away for years now...that I need to go through. I know I have some spares from my junkyard scouring days...or, you can call Paul - he may have some.

[140cilx]

Bud,
-if you bring'em, I'll buy one or two.

-Just out of curiosity, these are specific to SVO's again, or are these switches used interchangeably on other Fords?

[Jman]

I say wire in a relay when you do it. They sell automotive relays at autozone there like 6 bucks. 275-226 is the part number if you like to know. They are rated at 30 amps. And the great thing is, if it blows all it takes is the relay and not your switch.

[140cilx]

thanks for the relay part #. I would like to go that route, new switch w/ a relay for protection. I'm an electric/wiring retard - always have been. Great wiring successes for me have been wiring new stereo's in with all the speakers in phase.

A relay is like a fuse? Or it "relay's" power overloads elsewhere? Is it wired in series to the power going to the switch?

Anyone have install instructions for a do-it-yourselfer that doesn't know much?

-thanks for the assistance.

[Jman]

if you just remain calm about a relay its really simple.

think of it as 2 crossing circuits. 1 circuit triggers a switch that makes the other circuit complete.

it'll have the connections listed on the back of the box

12v in is connected to battery, 12v out goes to fog lights. then there is a ground, which obviously goes to the ground. the other one is a power wire that is wired to the fog light switch. when you flip the switch it completes the circuit between the switch and the ground which flips the internal switch on the relay and completes the circuit between the 12v in and 12v out.

It would be a good idea to put a fuse on the 12v in as close to the battery is possible. because if the wire somehow gets cut and you don't have a fuse it could short out.

[svobud]

The switch itself is not a SVO specific item. As a matter of fact - the switch used for the Prem Fuel and Fog light are exactly the same with different bezels.

You can try looking for the switch in any 86-back Mustang that had fog lights. Maybe even something like in a EXP Turbo.

I'm not sure if the MRK VIIs or Turbcoupes use the same switches - even though they did use the same marchal fog lights.

Maybe someone else can expand the answer a bit further...

[KevinK]

86 fog light switch was an under dash thing with a bracket that one would expect from the 60s. At least that what Ford sold me when I added the GT fog lights to an 86 back in 1987. It was nothing like the SVO switch. I could be wrong.

[SVO9844]

relay install help

can someone tell me how you would install this , battery and ground connection no problem, the other two accessory connections go to which wires? one from the fog light switch? which one. what about the other one.
thanks!

[Pat_in_L.A.]

Consider accessory the light.

Consider accessory terminal the switch.

Now go get a beer.

[SVO9844]

wires

which wire that comes off of the light switch to the fog light switch will
no longer be used? that same wire to the fog light switch should be cut and spliced to the accessory terminal on the relay from foglight switch? and the other terminal goes to the fog light wire harness before it splits to the two lights? which wires would they be? colors would help if anyone knows. I think I wrote that correctly.
Thanks alot

[Pat_in_L.A.]

You determine the colors, since you do the rewiring.

What used to be the load now becomes the signal to the relay.

I posted a diagram this month that has a good example regarding bosch style headlamp relays. Try a search using those terms.