Q
HAVEN’T THE FOGGIEST
I have a low-mileage ’82 GT in perfect shape except for the fog lights, which
won’t come on. I’ve checked for power at the lights with a test light. No power.
I went ahead and tried installing new bulbs anyway hoping it would fix the
lights. I don’t know much about electrical systems short of just checking for
power at the lights. What should I do next?
Joe Sawin
Via email
A
You started out correctly by checking for power at the lights. Most
of the time it’s a relay that’s stuck open, but let’s go through the motions.
For these tests, make sure the key is in the ON position and the
headlights are turned on. First, check for power at the switch. Using a
12-volt tester, test the red wire with a black stripe. If there’s no power,
check the No. 10 fuse. If it has power, then go to the relay and check the
orange wire with a black strip. No power there means there’s an issue
with the main power feed wire and/or the 20-gauge fusible link.
If you do have power at that wire, then check the tan wire with an
orange stripe. This is where I suspect you will have an issue. If there’s no
power here, then you have a stuck or bad relay. In 1979-1985, Ford used
a relay with a metal housing. These are next to impossible to find new.
The Ford part number is D9BZ-14512-A. I recommend going to any
auto parts store and getting a new pigtail for a Bosch-style relay and a
new Bosch relay. Use these to replace the old metal-style relay and your
lights should be working.
Q
VACUUM LEAK
I need help finding a vacuum leak on my engine. I can hear it under the intake but can’t find it. It’s a ’93 LX
convertible with a 5.0 and five-speed.
Frank Bickel
Viroqua, WI
A
With the right equipment you can pinpoint a vacuum leak in seconds. We use a smoke machine. (It’s
the same principle as the smoke machines used at concerts.) Any good auto shop should have one of
these. You simply hook it up to a vacuum line feeding into the intake and plug off the throttle body. Smoke
will soon come out of the hole where the vacuum leak is.
If you do not have access to one of these machines, there are a few common places to check for intake
leaks. Check the PCV valve grommet. As these get old and hard, they shrink and lose their seal. Next is
the canister purge vacuum hose. This is on the front of the intake just under the plenum. And, of course,
there are always those small, hard plastic lines that love to crack if you look at them wrong.
MEET MATT HIGHLEY
Matt, owner of Fox Mustang Restoration, brings years of experience, a passion for Fox-bodies, and a deep knowledge of
these cars to Fix My Fox. In 2004, Matt opened Fox Mustang Restoration to help keep these cars on the road.
To have Matt address your Fox Mustang issues just send your question, and a pic if possible, to
[email protected]. Put “Fix My Fox” in the subject line.
Issue 8 FOX Mustang Magazine 91