Topic: 65 GT Fog Light switch installatiion

[Brian Conway]

     Have the dash out and would like to explore a little and maybe learn a few thing from some of you guys ?  Fog light switch is out and identified by a C5ZB-15A214-B FOMOCO ink stamped on the one wire.  It does have the Flat spot on the threaded bezel mount.  The dash however is just a round hole.  In the area behind the AMP gauge the harness bundle has a paper tag C5ZB 15A006A FoMoCo C.P.C.  The harness behind the GAS gauge has a paper tag;C5ZB 11328-B SX FoMoCo.  Further; the tail lights DO NOT light up when the fog  lights are flipped on. The question: Factory GT Fog Light switch and harness's or Dealer installed ? Any other hallmarks to look for or stop here ?  Brian

[jwc66k]

Brian,
  For 1965 the fog light wiring was part of the under dash harness, and part of the engine compartment lighting harness. The switch part number, C5ZB-15A214-A, is correct for 1965; the hole is suspect but most likely legitimate, the book say make a hole, not a "D" hole ; C5ZB-15A006-A is the part number for clock wiring; C5ZB-11328-A fits into the group of numbers for starters as defined in Ford Car Parts (1975 ed) so it is a mystery. SX and C.P.C. are probably manufactures IDs. Is part number C5ZB-11328-A marked on a wire? I don't see the paper tag in your picture for this item.
Most add on Fog Lamps use the 1966 style switch, 1966 style under dash wiring, 1966 style under hood wiring, but the same circuit breaker. I think you may have a mix.
Jim

[Brian Conway]

     Thank you for taking a look and the sharing the info and your thoughts.  The C5ZB 11328-B  is on the tag in the last picture to the left side of the cluster opening.  The C5ZB 11328-B is on the backside, of the Tag, and I had to use a mirror to get the numbers. 
     I have read in the past and heard again recently that when the fog lights only are turned on they also light up the rear lights. Mine do not do that.  Should they ?  My fog lights only function when the headlight switch is pulled out.   An Alarm system was installed sometime back and the installer took some liberties with the wiring.  Thanks, Brian

[jwc66k]

Brian,
 The tail lights should come on with the fog lamp switch, I think my 65 Fastback does, it was built 5/11/65 in San Jose. Getting to the car to see if that's true is a bit difficult, a 66 Fastback is in the way sort of temporarily disassembled. I could not find a 65 wiring diagram for the fog light circuit in either the assembly manuals or the service manual.
I see the C5ZB-11328-B tag in lower corner, and all I can say is take another look. That block of numbers, 11328, falls in the starters group and that don't compute. I looked in the 65 Electrical manual looking for "close" numbers (xx328) but there was nothing. What options do you have?
(And I detest amateur wiring specialists, as you are discovering on your own.)
Jim

[rocket289k]

Hi Brian,

One thing that I couldn't see in the pictures is the plug on the fog light switch.  A factory '65 fog lamp switch will have 2 female plugs and 1 male plug.  I grabbed a quick picture of a '65 style fog switch reproduction part so you can see what I'm talking about. 

The '66 style (and typically the dealer added version) used 2 male plugs and 1 female plug. 

PS - Provided you have a complete wiring harness setup correctly the rear taillights will come on when you turn on the fog lights (with the headlights off).  I have a '65 GT as well.

Regards,

Ron

[Brian Conway]

     Thanks for the lighting info and these lights don't light up independent of the headlights.  About the  C5ZB 11328-B tag; had a second look and it may read 11B281-B .  From a past discussion about license plates I know your car is close to mine date wise.   Nice to know their are a couple of these cars and owners here to compare notes with.  My 65 is a basic GT no frills or extras except the Pony Interior.  A better picture of the Plug shows it to be the two female one male configuration ? 
     I think about removing the alarm system and then I see the wiring spaghetti mess and feel like leaving well enough alone.  Thanks,  Brian

[Brian Conway]

     Got a picture of the harness tag in question.  Reading backwards and in a mirror.  What do you get ?  Brian

[jwc66k]

The mystery part number is (wait for it) C5ZB-17B587-B which is the windshield wiper switch to motor harness for a single speed wiper.
Now for basic troubleshooting. If you have a 12V trouble light, the type that looks like a pen with a bulb on the top, a sharp point at the other and a 24 to 36 inch wire from the bulb end that has an alligator clip at the other end, you can see if you have power to the tail lights. If you don't have one, get one, it makes electrical life easy.
For all this you need to have the battery hooked up, the three prong connector to the switch disconnected and maybe someone looking at the tail lights (it helps with two people).
1. Find the hot pin in the connector - clip the alligator clip to something metal close by, then use the sharp point on each of the three contacts, pins or sockets, of the connector that goes to the main harness. When the bulb lights up, that's the hot contact. Do all three contacts.
2. Clip the alligator clip to that hot contact (pin or socket and MAKE SURE THAT THE CLIP DOES NOT TOUCH METAL), and then place the sharp point in one of the other contacts. The fog lights will come on with one of those contacts, the remaining one is the circuit that goes to the tail lights.
Some warnings: don't keep the test lamp in the circuit too long; the fog and or tail lights will not be as bright as normal;  you may burn out the test lamp bulb. If the fog and tail lamps both come on, the problem may be in the switch.
Jim

[Brian Conway]

     Gee can clearly see that now.  I do have a circuit tester and will print this page for the next time I am in there.  I really don't like fooling around with this fragile aged wiring.  Thanks again.  Brian 

[Brian Conway]

[quote author=jwc66k   For 1965 the fog light wiring was part of the under dash harness, and part of the engine compartment lighting harness wiring,  Jim

Just to be clear; Does that mean all 65 Mustangs or GT mustangs only ?  Brian

[jwc66k]

Just to be clear; Does that mean all 65 Mustangs or GT mustangs only ?  Brian

For 1965 only, all factory fog light equipped cars, whether they had the GT (PIO) package, or the deluxe interior, had the fog light wiring included. Many deluxe interior cars did not have the fog lights but had the wiring.
Jim

[steve_f]

     Thank you for taking a look and the sharing the info and your thoughts.  The C5ZB 11328-B  is on the tag in the last picture to the left side of the cluster opening.  The C5ZB 11328-B is on the backside, of the Tag, and I had to use a mirror to get the numbers. 
     I have read in the past and heard again recently that when the fog lights only are turned on they also light up the rear lights. Mine do not do that.  Should they ?  My fog lights only function when the headlight switch is pulled out.   An Alarm system was installed sometime back and the installer took some liberties with the wiring.  Thanks, Brian

Brian,
The tail lights do come on with the fog lights on my 5/15/65 SJ fastback GT.
Steve

[Brian Conway]

     Thanks guys.  My fog light switch does not function correctly and for now I will be satisfied with the way it is.  I suspect the problem lies somewhere in that huge gob of electrical tape.  So until I have a good reason to open that can of worms I will have to be happy with what I have.  Brian

[midlife]

     Thanks guys.  My fog light switch does not function correctly and for now I will be satisfied with the way it is.  I suspect the problem lies somewhere in that huge gob of electrical tape.  So until I have a good reason to open that can of worms I will have to be happy with what I have.  Brian

If you are referring to the large bundle next to the steering column, that's the way it is supposed to be (the wiring from the turn signal switch) and has nothing to do with the foglamp wiring.

My guess is that the switch itself is bad, particularly if it is original.  Very few original switches that I've seen work correctly now.

[jwc66k]

If you have the switch out, at least where the back is accessible, you can use a small jumper (a "U" bent metal paper clip works fine) on the terminals to check out the light circuit. What the switch does is connects 12V to both the fog lamps and tail lamps, so, based on Ford's practice (and most other circuits with power in them), the socket in the harness plug is power and the pin in the switch connector supplies that power to the switch. That would be the top wire in your picture, so with a faithful observer at the rear of your car, jump that contact at the back of the switch to either of the two other contacts and see. Again, don't allow the jumper to hit body metal. If the tail lights work (and you can solder) get back to us.
Jim