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Topic: Tail lamp fuse (Read 8710 times) previous topic - next topic

Tail lamp fuse

Reply #15 –
Ok. Now I'm better understanding how I can do this. Thanks for the help guys. I'll let you know what I find.
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #16 –
So I've torn the dash back out, I've tested the brake lights, and turn signals. They all work. I pulled out the 4 bulbs for the two rear markers, and the lic. Plate lights, tested each bulb. Good to go. I've searched the light blue and red striped wire behind the dash. No breaks other than a bad bulb for the headlight switch bezel. I'm wondering if the coach lamps could be bad and causing the fuse to blow when the switch is moved to parking lamps. Are they on the same circuit? I'm about to check the brown wires again, just wondered if the electroilluminescent lamps could be at fault. Thoughts?
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #17 –
Quote from: FOX-XR7;448194
So I've torn the dash back out, I've tested the brake lights, and turn signals. They all work. I pulled out the 4 bulbs for the two rear markers, and the lic. Plate lights, tested each bulb. Good to go. I've searched the light blue and red striped wire behind the dash. No breaks other than a bad bulb for the headlight switch bezel. I'm wondering if the coach lamps could be bad and causing the fuse to blow when the switch is moved to parking lamps. Are they on the same circuit? I'm about to check the brown wires again, just wondered if the electroilluminescent lamps could be at fault. Thoughts?


You are wasting you time checking anything that isn't below F15 on on that wiring diagram...

Tail lamp fuse

Reply #18 –
Quote from: FOX-XR7;448194
I'm wondering if the coach lamps could be bad and causing the fuse to blow when the switch is moved to parking lamps. Are they on the same circuit? I'm about to check the brown wires again, just wondered if the electroilluminescent lamps could be at fault. Thoughts?
Yup, they are connected to parking lamps too, as well as lamp out warning module (if you have one).

Tail lamp fuse

Reply #19 –
So I've pulled all the bulbs out of the trunk and I jumped the blown fuse with my test light and it lit up. So that tells me there is still a short to ground other than the bulbs. I pulled the harness up from beside the door jam and found nothing wrong with the wire. I guess my next step is I want to check the sockets in the trunk 5o see if they could be shorted. I neglected to check them the first time I had the bulbs out. Then if they all check out. I'll try and access the wiring from the door jam to the trunk it runs along the back seat it looks like. Also looks like a royal pain. But I already got the car torn apart so what's a backseat right? I'll keep you guys posted as to what I find.
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #20 –
Quote from: FOX-XR7;448122
Here's a random thought....some guys at work said it could be my tailights bulbs themselves? That they may be grounded through the bulb? And if I bulb shorted, that could be blowing the fuse. Is this myth? Or could this be possible?
I actually saw this once on a pickup.  The filament was offset somehow, and when the truck would go over a bump it would jump contact from tail power to brake ground IN THE BULB, and blow the fuse.  I should have kept it, people usually don't believe me.

Tail lamp fuse

Reply #21 –
Well I cut apart the line from the fuse to wear it connects to the rear taillight wires. I then pulled all the bulbs out and one by one, connected the turn/brake/marker lamp brown wires to the main brown wire from the fuse. Meanwhile I have my test light across the blown fuse with the power on. The test light never lit. As soon as I installed a lightbulb, the test light lit. Now is it only doing this because the bulb is completing the circuit to ground? I'm thoroughly confused now as to why this  fuse keeps blowing. I don't understand what I'm doing wrong.
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #22 –
Quote from: FOX-XR7;448491
Well I cut apart the line from the fuse to wear it connects to the rear taillight wires. I then pulled all the bulbs out and one by one, connected the turn/brake/marker lamp brown wires to the main brown wire from the fuse. Meanwhile I have my test light across the blown fuse with the power on. The test light never lit. As soon as I installed a lightbulb, the test light lit. Now is it only doing this because the bulb is completing the circuit to ground? I'm thoroughly confused now as to why this  fuse keeps blowing. I don't understand what I'm doing wrong.

Yes... If this is a LED test light any resemblance of a short or bulb installed will light the test light... A test light with a 194 bulb or similar will light dimly with only a side marker installed and go to full bright with a couple installed...

Good news is there is no short and it appears the fuse is undersized... Install a 15 amp fuse and try it... If it blows well something is up, if not you're golden...

Note I believe I saw the models without system sentry used a 15A IF that's the case models with sentry should have at least as much rating...

Tail lamp fuse

Reply #23 –
Yeah Its definitely a red 15 amp fuse in it that keeps blowing. (I've toasted like 6 lol) I guess something is still jacked up with this thing.
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #24 –
Quote from: FOX-XR7;448496
Yeah Its definitely a red 15 amp fuse in it that keeps blowing. (I've toasted like 6 lol) I guess something is still jacked up with this thing.
If it blows fuse with wiring to rear of car disconnected problem has to be between fuse panel and system sentry module(it mounts over glove box opening inside dash)...

Red fuses are 10A, BLUE are 15..

Tail lamp fuse

Reply #25 –
Quote from: TurboCoupe50;448499
If it blows fuse with wiring to rear of car disconnected problem has to be between fuse panel and system sentry module(it mounts over glove box opening inside dash)...

Red fuses are 10A, BLUE are 15..

Right. Sorry my mistake. I have been putting 10 amp fuses in. I know it's fuse #15.
Is the system sentry module the box where the brn and WHT wires go to lamp out warning module? Is it the same thing?
So the switch is not likely the culprit? Or could that be as well?
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #26 –
Quote from: TurboCoupe50;448260
You are wasting you time checking anything that isn't below(fed by) F15 on on that wiring diagram...


This. ^^^^

Tail lamp fuse

Reply #27 –
Well, checked for continuity from power wire in trunk up to removed fuse. I got o.l. Which is good. So there is no short to ground in that wire. I took all bulbs out and threw in a 10amp fuse out of an old wiring harness. Switch on, it didn't blow the fuse. So I put all bulbs back in and wah laa, I got lights. Figured I'd see if this other 10 amp blew then I'd throw in a 15 to try. Now the only thing I did different this time was I used a fuse from a factory wiring harness (spare I have here) instead of tractor supply Chinese value pack. Could those other "value fuses" (if you will) be slightly underrated? Which may answer why they kept blowing? I don't know what I did, but it seems to work fine now.
1988 Mercury cougar XR7- 302 bored .030 over, gt40p heads, F303, AlexsParts spring and seal kit, explorer upper and lower intake, 70mm tb, maf conversion, 75mm maf, fenderwell cai, 24 lb injectors, T5 conversion, bbk h pipe, Slp lm, 3.73 rear, 4 wheel disc conversion, 5 lug conversion. :D :D

Tail lamp fuse

Reply #28 –
The ole puppiesinese fuse syndrome huh??

That's why I suggested a 15 amp(that never happened)... After you said the test light didn't light when the bulbs were removed I knew you were chasing a imaginary problem...
 

Tail lamp fuse

Reply #29 –
I was doing some working in Montana, 1600 miles away from home. I accidentally left my headlights on when we pulled up to a bar to celebrate finishing the job and getting ready to leave for home the next day. When i went to jump the car, the jumper cables were mis marked (two red clamps on one side) and didn't realize it

It was a balmy 12 degrees with high winds and snow so i sat in the trunk as i reverse charged my battery and blew every fuseable link and fuse.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com