Does anyone have a backlite heater?

[71fast]

I was looking at the electrical drawings in the data section showing a backlite heater. Where is the switch and dashlite located? What do they do? There doesn't seem to be many parts for this anywhere.

 

[kcmash]

I was looking at the electrical drawings in the data section showing a backlite heater. Where is the switch and dashlite located? What do they do? There doesn't seem to be many parts for this anywhere.

I have one. THe slang term is rear window defogger. Switch and indicator light are by your left knee on the lower dash,

 

[Mike429cj]

I was looking at the electrical drawings in the data section showing a backlite heater. Where is the switch and dashlite located? What do they do? There doesn't seem to be many parts for this anywhere.

Here is a picture of mine. I have since replaced it since the switch was broken. Also replaced the "Belts" light which I was missing. Thanks to member Eddyw for selling me that hard to find part.

And yes the parts are hard to find. Switches can be rebuilt using a power top switch but you have to already have a switch to do that. The back glass with the heater grids is also rare and not reproduced. I picked up a nice one on Craigslist last year for next to nothing. Guy just wanted to get rid of it. I figured it was good to have a spare just in case!

 

[71fast]

I didn't think anybody would call a rear window a backlite. I never made the connection.

Do you know where the backlite relay is located? Maybe above the glove compartment?

 

[Steve73QMach1]

Here is a not so great picture of mine. Like Mike, the knob was broken off when I purchased the car from the original owner. I had a spare switch in my stash of parts so that made replacing it pretty easy. They tend to break off when the drivers feet hit the switch on exiting from the car. I have to be real careful getting out of this car so I don't kick it and snap it off. The indicator light for the unit is just to the left of the switch and glows red when the defrost is on.

 

[OMS]

I didn't think anybody would call a rear window a backlite. I never made the connection.

Do you know where the backlite relay is located? Maybe above the glove compartment?

Yes the relay would be on the electrical plate above the glove box

Don

 

[eddyw]

I was looking at the electrical drawings in the data section showing a backlite heater. Where is the switch and dashlite located? What do they do? There doesn't seem to be many parts for this anywhere.

if you are interested:

http://www.ebay.com/itm/1973-Mustang-Heated-Backlite-Switch-Harness-Relay-Etc-71-72-/301520730224?pt=Motors_Car_Truck_Parts_Accessories&hash=item4634093870&vxp=mtr

Eddy[attachment=29722]

 

[Carolina_Mountain_Mustangs]

I was looking at the electrical drawings in the data section showing a backlite heater. Where is the switch and dashlite located? What do they do? There doesn't seem to be many parts for this anywhere.

if you are interested:

http://www.ebay.com/itm/1973-Mustang-Heated-Backlite-Switch-Harness-Relay-Etc-71-72-/301520730224?pt=Motors_Car_Truck_Parts_Accessories&hash=item4634093870&vxp=mtr

Eddy

Just info,

I have read somewhere that I think 7% or the Mach 1 and Sportsroof cars had the "Electric Rear Window Defroster" as stated on the window sticker. Don't know how they could come up with that. I had asked Marti to try to sort the data by options once and he said it was not set up to sort. My 73 Mach and 72 T-5 both have the option that cost $57.00 new. I did break the knob of my switch also with catching my pants leg on the handle. I think it was maybe 1975 and when I went to the dealer to get one he said they were not available. So I had him do a nation wide search for them at dealers and I think there were three so I bought all of them. That is another one of those parts that turned into gold.

Will watch the one on eBay to see if it sells.

David

 

[Boss1Ray]

For historical purposes I decided to post up the different wiring components of the defroster glass from the ebay ad.











Ray

 

[eddyw]

A few photo's extra:

 

[midlife]

That flat white connector with two locking tabs is as rare as hen's teeth. It is not reproduced and is also used on 1970 Mach 1 sportslamp switches.

I've run across about 60 71-73 harnesses and have yet to see a rear defogger system. If the 7% figure is accurate, I would have seen at least 3 of them. However, they are separate harnesses so I dunno...

Marti's Mustang By the Numbers has the following numbers for rear defroggers (apparently, the number of frogs were increasing in the early 70's):

6578 of149,682 in 1971 4.4%

8478 of 125,093 in 1972 6.8%

16289 of 134,867 in 1973 12.1%

 

[Carolina_Mountain_Mustangs]

That flat white connector with two locking tabs is as rare as hen's teeth. It is not reproduced and is also used on 1970 Mach 1 sportslamp switches.

I've run across about 60 71-73 harnesses and have yet to see a rear defogger system. If the 7% figure is accurate, I would have seen at least 3 of them. However, they are separate harnesses so I dunno...

Marti's Mustang By the Numbers has the following numbers for rear defroggers (apparently, the number of frogs were increasing in the early 70's):

6578 of149,682 in 1971 4.4%

8478 of 125,093 in 1972 6.8%

16289 of 134,867 in 1973 12.1%

I was looking through some of the stuff in the garage and I have 3 of the switches NOS in the box looks like bought them in the 80's.

David

 

[jb73Mach]

Midlife,

PM me if interested. Can probably work something out.

 

[Carolina_Mountain_Mustangs]

That flat white connector with two locking tabs is as rare as hen's teeth. It is not reproduced and is also used on 1970 Mach 1 sportslamp switches.

I've run across about 60 71-73 harnesses and have yet to see a rear defogger system. If the 7% figure is accurate, I would have seen at least 3 of them. However, they are separate harnesses so I dunno...

Marti's Mustang By the Numbers has the following numbers for rear defroggers (apparently, the number of frogs were increasing in the early 70's):

6578 of149,682 in 1971 4.4%

8478 of 125,093 in 1972 6.8%

16289 of 134,867 in 1973 12.1%

I was looking through some of the stuff in the garage and I have 3 of the switches NOS in the box looks like bought them in the 80's.

David

So a little under 8% for the three years. I would assume that the defogger was offered on the coupe models but do not know that never paid any attention to it. I know when I ordered a Maverick Grabber in 71 I did not get the defogger because I had never had a car with the wire in the back window. I did not get air either just do not like it. When I ordered the Mach 1 I got air but pulled the belt off as soon as I got home.

David

 

[Mesozoic]

I have a car with factory rear defroster and the switch is intact, but the knob has snapped off via PO. I don't understand why the car was ordered with one since it was purchased new in Phoenix, AZ and has been in Arizona its whole life, but whatever. It does appear to be a rare option. Does anyone know where to find replacement knobs and also where to find the little lights that mount adjacent to the switch for Park and Brake?

 

[OMS]

That flat white connector with two locking tabs is as rare as hen's teeth. It is not reproduced and is also used on 1970 Mach 1 sportslamp switches.

I've run across about 60 71-73 harnesses and have yet to see a rear defogger system. If the 7% figure is accurate, I would have seen at least 3 of them. However, they are separate harnesses so I dunno...

Marti's Mustang By the Numbers has the following numbers for rear defroggers (apparently, the number of frogs were increasing in the early 70's):

6578 of149,682 in 1971 4.4%

8478 of 125,093 in 1972 6.8%

16289 of 134,867 in 1973 12.1%

Randy you need to take the convertibles out of the totals

I have a car with factory rear defroster and the switch is intact, but the knob has snapped off via PO. I don't understand why the car was ordered with one since it was purchased new in Phoenix, AZ and has been in Arizona its whole life, but whatever. It does appear to be a rare option. Does anyone know where to find replacement knobs and also where to find the little lights that mount adjacent to the switch for Park and Brake?

You can use the knob from a new power top switch

Item #D1ZZ-15668

71-73 CONVERTIBLE TOP SWITCH ASSEMBLY

Includes correct plastic knob and die cast chrome nut. Made exactly like originals. Price: $49.95

Hard to find PARK and BELTS lights

 

[Mesozoic]

That flat white connector with two locking tabs is as rare as hen's teeth. It is not reproduced and is also used on 1970 Mach 1 sportslamp switches.

I've run across about 60 71-73 harnesses and have yet to see a rear defogger system. If the 7% figure is accurate, I would have seen at least 3 of them. However, they are separate harnesses so I dunno...

Marti's Mustang By the Numbers has the following numbers for rear defroggers (apparently, the number of frogs were increasing in the early 70's):

6578 of149,682 in 1971 4.4%

8478 of 125,093 in 1972 6.8%

16289 of 134,867 in 1973 12.1%

Randy you need to take the convertibles out of the totals

I have a car with factory rear defroster and the switch is intact, but the knob has snapped off via PO. I don't understand why the car was ordered with one since it was purchased new in Phoenix, AZ and has been in Arizona its whole life, but whatever. It does appear to be a rare option. Does anyone know where to find replacement knobs and also where to find the little lights that mount adjacent to the switch for Park and Brake?

You can use the knob from a new power top switch

Item #D1ZZ-15668

71-73 CONVERTIBLE TOP SWITCH ASSEMBLY

Includes correct plastic knob and die cast chrome nut. Made exactly like originals. Price: $49.95

Hard to find PARK and BELTS lights

Thank you for that information. Furthermore, can anyone confirm whether the backlite switch is merely a momentary switch or something more complex?

 

[jb73Mach]

There is no timer relay - momentary on, momentary off. Some of the similar vintage Lincolns did have a timer - rear defroster went off after a specified time but not for the Mustangs.

 

[Carolina_Mountain_Mustangs]

That flat white connector with two locking tabs is as rare as hen's teeth. It is not reproduced and is also used on 1970 Mach 1 sportslamp switches.

I've run across about 60 71-73 harnesses and have yet to see a rear defogger system. If the 7% figure is accurate, I would have seen at least 3 of them. However, they are separate harnesses so I dunno...

Marti's Mustang By the Numbers has the following numbers for rear defroggers (apparently, the number of frogs were increasing in the early 70's):

6578 of149,682 in 1971 4.4%

8478 of 125,093 in 1972 6.8%

16289 of 134,867 in 1973 12.1%

Randy you need to take the convertibles out of the totals

I have a car with factory rear defroster and the switch is intact, but the knob has snapped off via PO. I don't understand why the car was ordered with one since it was purchased new in Phoenix, AZ and has been in Arizona its whole life, but whatever. It does appear to be a rare option. Does anyone know where to find replacement knobs and also where to find the little lights that mount adjacent to the switch for Park and Brake?

You can use the knob from a new power top switch

Item #D1ZZ-15668

71-73 CONVERTIBLE TOP SWITCH ASSEMBLY

Includes correct plastic knob and die cast chrome nut. Made exactly like originals. Price: $49.95

Hard to find PARK and BELTS lights

Thank you for that information. Furthermore, can anyone confirm whether the backlite switch is merely a momentary switch or something more complex?

I have already put the switches up or I would have hooked a meter to one. The pic is some NOS ones that I bought in 1982 and have squirreled away. They cost a little of $11.00 each back then. Sorry the pic is not that good. It looks like they were made by two different suppliers different ink stamping on them. When mine broke it broke the metal part the knob screwed on so getting the convertible top one would do no good since nothing there to attach to. Most if not all of the companies that made these are out of business due to China and such. There was one local company here CTS, Chicago Telephone Service. They made switches for Ford and others. The turn signal switch that also had the cruise control on it was made there. Ford wanted the entire switch for less than $.99 so they went off shore. Can you believe 99 cents and if you went to buy one it was probably at least $30.00 back then. I guess the handling is the expensive part, thanks unions.

David