North American Turbocoupe Organization



bulb check on an 86?
84TBirdTurbo42 Offline
Senior Member
#1
Hey all. Just starting to run threw the demons of my 86. It currently has NO ENGINE. i'm just curious as to what comes on when first hit KOEO. My check engine light doesn't illuminate. I wasn't sure if they did or not. I also cannot self test the PCM right now. I have a suspicion that because i don't have an engine in there, and all the sensors are open, it won't do anything. THE PCM does have Power and the relay is good. It also was putting out 5VREF to the vam and TPS sensor. It does have some sort of aftermarket PCM i'd be happy to ditch.

so, what bulbs illuminate when you first turn the key?

i don't want to be chasing a problem that doesn't exist. 
To explain what i'm dealing with, the car had the wiper switch wires cut, and soldered with speaker wire....
Chris Perry
1984 Ford Thunderbird Turbo Coupe. Dead, NY rot killed her
1986 Thunderbird shell, swapping parts from the 84.
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Jeff K Offline
Administrator
#2
I cant speak directly to your 86, but in general all Ford PCMs, even thru the present day, turn on the CEL when the key is turned to RUN but the engine is not running.

FIrst thing I would check is to see if the CEL bulb is burned out or if it has been removed. I have seen cases where someone trying to sell a Ford with a CEL on remove the bulb so the prospective buyer doesnt know the CEL is on.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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84TBirdTurbo42 Offline
Senior Member
#3
I had to put one in the hole last night. It didnt change still no CEL. The thing i find funny as well is, i cant activate a self test either. Oh well, back to the drawing board
Chris Perry
1984 Ford Thunderbird Turbo Coupe. Dead, NY rot killed her
1986 Thunderbird shell, swapping parts from the 84.
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JT Offline
Posting Freak
#4
The shop manual wiring diagram does not show a circuit for the Check Engine light. That said, as Jeff states, the typical behavior is the Check Engine light illuminates on Key On Engine off and remains on until it receives signals indicating an ignition pulse while cranking.

I believe the only other light you'd see is the fasten seat belt lamp. Brake light would do a bulb check during Crank mode as well as the Check Turbo lamp (if I recall correctly). Given the TC has full instrumentation and way less modules than today's vehicles, there isn't a lot of warning lamps or bulb check tests.

You might want to make sure the EEC is receiving power by checking the EEC relay for power. If EEC doesn't receive Key On power, there will be no Check Engine lamp nor ability to enter Self-Test mode.
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84TBirdTurbo42 Offline
Senior Member
#5
Well the CEL doesnt work. I was able to perform a self test with both my EEC’s. Forgot about that damn orange ground wire.

So at least thats good. Now it might be time to find a cluster. Considering it does have an 87 cluster in it anyways.
Chris Perry
1984 Ford Thunderbird Turbo Coupe. Dead, NY rot killed her
1986 Thunderbird shell, swapping parts from the 84.
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Jeff K Offline
Administrator
#6
No sure on the 86 TC, but my 86 Tbird 5.0 SEFI did not come with a CEL.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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