Technical => Electrical Tech => Topic started by: jcassity on May 30, 2009, 11:16:18 PM
Title: bulb question
Post by: jcassity on May 30, 2009, 11:16:18 PM
87coug 20th
one either side of the grille, there are double element bulbs. why are they double element? I swapped out the oem yellow for clear. Also added my new"er" grille and complete clear lamps up front.
I tested a few things and did not see what function made the second element light up.
Title: bulb question
Post by: Watchdevil on May 31, 2009, 01:25:49 AM
Quote from: jcassity;275175
87coug 20th
one either side of the grille, there are double element bulbs. why are they double element? I swapped out the oem yellow for clear. Also added my new"er" grille and complete clear lamps up front.
I tested a few things and did not see what function made the second element light up.
If you have an 87, there are two sets of lights, one on the corner and one inboard. As designed from the factory, the outer ones double as turn signals and parking lamps while the inner ones function only as the parking lamps.
See if it is possible that you got the bulb and wiring sockets mixed up between inboard and outboard. The outboard bulbs should have dual filament sockets. If that is correct, check for 12V in the socket with the parking lamps on. Could be a bad socket not contacting the base of the bulb. It could also be bad wiring connections. Does it not light up on both sides? Another thing to check is to see if the bulb is inserted the correct way in the socket. The sides of the bulb base has pins. One is set higher than the other and is designed to only go in one way. However many times I have seen these bulbs forced to go in the wrong way in the socket.
Title: bulb question
Post by: jcassity on May 31, 2009, 01:36:11 AM
Quote from: Watchdevil;275186
If you have an 87, there are two sets of lights, one on the corner and one inboard. As designed from the factory, the outer ones double as turn signals and parking lamps while the inner ones function only as the parking lamps.
See if it is possible that you got the bulb and wiring sockets mixed up between inboard and outboard. The outboard bulbs should have dual filament sockets. If that is correct, check for 12V in the socket with the parking lamps on. Could be a bad socket not contacting the base of the bulb. It could also be bad wiring connections. Does it not light up on both sides? Another thing to check is to see if the bulb is inserted the correct way in the socket. The sides of the bulb base has pins. One is set higher than the other and is designed to only go in one way. However many times I have seen these bulbs forced to go in the wrong way in the socket.
Im not sure where you are going with all that.
does anyone know the answer to the question? Im a little stumped but the evtm might tell me more.
Title: bulb question
Post by: jcassity on May 31, 2009, 01:58:22 AM
am i reading this right? second filiment was never intended to be used? I do have lamp out warning but it doesnt seem relevent.
Title: bulb question
Post by: Watchdevil on May 31, 2009, 02:02:03 AM
Both inner and outer lamps used double filament bulbs. Whichever lamp serves as your turn signal, the opposite lamp only comes with the parkinglamps... Both inner and outer lamps come on with the parking lamps.
Title: bulb question
Post by: jcassity on May 31, 2009, 02:22:30 AM
Quote from: Watchdevil;275190
Both inner and outer lamps used double filament bulbs. Whichever lamp serves as your turn signal, the opposite lamp only comes with the parkinglamps... Both inner and outer lamps come on with the parking lamps.
does this mean something that helps answer the question?
Title: bulb question
Post by: Watchdevil on May 31, 2009, 02:34:23 AM
Quote from: jcassity;275194
does this mean something that helps answer the question?
It should.. Ford from the factory used dual filament bulbs in both sets of lights inner and outer but they only used the dim portion of the bulb for the lamp that does not operate as a turn signal. The bright filament was not originally wired to function.
Title: bulb question
Post by: TurboCoupe50 on May 31, 2009, 05:51:10 AM
Quote from: Watchdevil;275196
The bright filament was not originally wired to function.
well after three posts you finally stated how it's wired(or isn't in this case)...
Scott I dunno why they used a dual filament lamp for the inside lamps, T-Birds are the same... Maybe Ford wasn't trusting of the smaller size single filament lamps??? I can't remember seeing a 3057 style lamp with a single filament...
Title: bulb question
Post by: Thunder Chicken on May 31, 2009, 09:01:32 AM
Ford still does this. On 96-09 Mustangs the innermost rear light is park only, but it's a dual filament bulb. Ford simply didn't add the third "stop/turn" wire. As to why it was done I'm sure it's a cost cutting reason, probably cheaper to buy the 3057 style bulbs in bulk than to buy two different type bulbs
Title: bulb question
Post by: jcassity on May 31, 2009, 11:01:02 AM
hey watchdevil i have a curiosity,,,,,,, can you verify your inner headlamps on the bird hot wire colors?
I have a theory that occured to me last night while swapping the header panel lenses.
The theory is,,,, The inner lighting on 4eyes were wired out because these lamps were bulb assemblies.
The inners on 87-88 were bulb housings and not capable of containing the heat disipation of both elements due to the cubic inches of space within the housing. From an engineering perspective, ford probably decided the wattage of both elements being on exceeded the space required to light both up so they wired only the low beam.
Thunderchicken,, i might be reading too deap into the pony comment but the inner fronts on my coug's have three conductors, 2+g. The wire is there but prob dead end somewhere.
Title: bulb question
Post by: TurboCoupe50 on May 31, 2009, 12:01:42 PM
Scott in the '86 EVTM, wiring is shown with the dual filament lamp with only one element connected, same as the drawing you posted...
Title: bulb question
Post by: jcassity on May 31, 2009, 12:10:23 PM
well, that shoots that theory down.
Title: bulb question
Post by: CoogarXR on May 31, 2009, 12:11:06 PM
It's been a while since I had my last 87, but it seemed to me that the hazard flashers made the inners light up...?
Maybe not, heh.
CoogarXR
Title: bulb question
Post by: TurboCoupe50 on May 31, 2009, 01:00:34 PM
Quote from: CoogarXR;275247
It's been a while since I had my last 87, but it seemed to me that the hazard flashers made the inners light up...?
Maybe not, heh.
CoogarXR
Since the EVTM shows the high side as not connected, not likely...
Title: bulb question
Post by: Watchdevil on May 31, 2009, 02:18:50 PM
Quote from: TurboCoupe50;275207
well after three posts you finally stated how it's wired(or isn't in this case)...
Scott I dunno why they used a dual filament lamp for the inside lamps, T-Birds are the same... Maybe Ford wasn't trusting of the smaller size single filament lamps??? I can't remember seeing a 3057 style lamp with a single filament...
Yeah sorry it took three posts but I misunderstood when I read his first post assuming he could not get something to light up that was supposed to. The more he explained the more I realized that he was referring to the socket that only uses one filament.
Quite simply, Ford probably just found it unesssary to have to have two different type bulbs on the assembly line when one will do the job. Just like they do for the taillamps of the 96+ Mustangs where all three sections use the same bulbs but the innermost section only lights up with the running lights but not the brakes and turn signal.
Title: bulb question
Post by: Watchdevil on May 31, 2009, 02:31:33 PM
Quote from: jcassity;275226
hey watchdevil i have a curiosity,,,,,,, can you verify your inner headlamps on the bird hot wire colors?
I have a theory that occured to me last night while swapping the header panel lenses.
The theory is,,,, The inner lighting on 4eyes were wired out because these lamps were bulb assemblies.
The inners on 87-88 were bulb housings and not capable of containing the heat disipation of both elements due to the cubic inches of space within the housing. From an engineering perspective, ford probably decided the wattage of both elements being on exceeded the space required to light both up so they wired only the low beam.
Thunderchicken,, i might be reading too deap into the pony comment but the inner fronts on my coug's have three conductors, 2+g. The wire is there but prob dead end somewhere.
The wiring for the pre-87 four eyed headlamps was simply changed to combine the wiring for the single dual function headlamp bulbs of the 87-88 models.
It's not clear why Ford found it necessary to make a small inner parkinglamp when a larger headlamp lens incorporating that space would have worked. Since they used a seperate parking lamp inboard, I think they just lit that area as a parking lamp for visual balance. There is no need to make it a turn signal when only one is needed per side and positioned on the corners for best visibility.
For 1989, Ford reverted back to dual beam headlamps and combination turn/parking lamps on the corners. For 1994-97 it reverted back to the 87-88 setup.
When I had my 1989 Tbird, I installed a 1996-97 style front end on mine with the newer lights. I had to modify the wiring from dual beam to single beam headlamps, plus tap into the wiring of the corner parkinglamps to get the inner ones to operate. At that time I decided to make the inner parking lamps more functional by wiring a "daytime running lamp" circuit on a seperate switch using the normally unused bright filament.
Title: bulb question
Post by: Thunder Chicken on May 31, 2009, 03:43:24 PM
Quote from: jcassity;275226
Thunderchicken,, i might be reading too deap into the pony comment but the inner fronts on my coug's have three conductors, 2+g. The wire is there but prob dead end somewhere.
What colour are the three wires? If there are two the same colour and one ground, (IE two browns and a black) that just means that both brown wires are connected to the same terminal inside the socket, and Ford simply used the socket as a splice to carry the park circuit elsewhere.
Title: bulb question
Post by: CoogarXR on May 31, 2009, 04:19:17 PM
Could somebody with an 87-88 cougar humor me and try their hazards? The more I think about it, I could almost swear that they blinked... I know the schematics say otherwise, but my memory is screwing with me.
CoogarXR
Title: bulb question
Post by: ipsd on May 31, 2009, 06:24:33 PM
Had an 88 cougar and I don't remember them blinking but it has been 6yrs or more since then. My current daily driver is a 94 cougar XR7 and it has those smaller middle lights also. They don't blink and also have the dual filament bulb. Have you tried a single filament bulb? Not sure about the 87-88 but the earlier ones take the older 1157 round socket style bulbs those won't interchange with 1156 due to the difference in the teats that stick out to hold the bulb in. Now if it has the blade type socket 3057/3157/4075/4114/4157 then I do believe that you can swap in a 3056/3156 bulb. Hope that helps!
Stuckman
Title: bulb question
Post by: hwy73 on May 31, 2009, 09:52:22 PM
Quote from: CoogarXR;275279
Could somebody with an 87-88 cougar humor me and try their hazards? The more I think about it, I could almost swear that they blinked... I know the schematics say otherwise, but my memory is screwing with me.
CoogarXR
My 88 XR-7 with stock wiring does not flash the inside parking lamps with the 4-way flashers or turn signals.
Title: bulb question
Post by: jcassity on May 31, 2009, 10:30:17 PM
Quote from: hwy73;275337
My 88 XR-7 with stock wiring does not flash the inside parking lamps with the 4-way flashers or turn signals.
same here,, just tried it.
thunderchicken,, ill get the wire colors tomorrow. prob the same colors as yours though.