[JBAUER4363]

After earlier post misunderstood Midlife"s advice and thought I needed a flasher switch, underdash.
Purchased one
Plugged in
Everything works, turn signals flashers everything GREAT
But wait-Backed out of garage, No turnsignals at all???
Flashers work Turnsignals Dead!
Checked fuses-Blown Fuse!
I think it happened when I stepped on brake!
Like I said flashers work but when I step on brakes they dont flash? Is this normal?
Was going to give up but maybe someone has seen this before. the fuse that blew was a 25 amp, Is this correct for this application?
Any Ideas would be helpful
THANKS IN ADVANCE
Jan Bauer
70 Mach 1

 

[JBAUER4363]

Keeps getting stranger
Put in new fuse tried turn signals- They ( the turn signals ) work fine!
Pushed on brake!- They work fine!
Turned on flashers- They work fine!
Turned on lights - They work fine
Wipers - They work fine!
Fog lamps - They work fine!
Push in clutch move car 2 inches Fuse Blows!!! - They are dead!!!
I dont know if they blew when as I pushed in clutch on as I moved car. Out of fuses.
Again ANY ideas would be helpful!
THANKS IN ADVANCE
Jan Bauer
70 Mach 1

 

[sharkmouth]

I'd take a good look underdash for fraying of wire harnesses

 

[mgmradio]

You have an intermitant short to ground.I'd look under the dash and observe the brake and clutch pedal arms as they are moved.See if they are contacting or moving any of the wiring.Also check around the E-brake assembly.Good luck.

 

[DavidG]

It sounds like you have a wire that is grounding out or a part that is shorting to ground. The hard part is finding the offending wire or part that is causing this. Start by looking in the area that seems to make the fuse blow, around the pedals from what you have said. Or something that involves the car moving, again going on what you have said so far. Maybe the steering wheel column area. These problems can be very frustrating and hard to locate sometimes.

 

[JBAUER4363]

Thanks for the quick response. Thats why this forum is so great!!!!
Just got more fuses and will try to isolate the problem area.
THANKS AGAIN!
Jan Bauer
70 Mach 1

 

[JBAUER4363]

Update!!
Went through previous routine with new fuse everything OK
Now is the time to test clutch theory
Push in 1/3 Nothing
Push in 2/3 Nothing
Push in agaist floor BAM fuse blows!!
Looked under there but cant see anything touching.
But you guys where right on target again!
When It cools off later Ill do a closer inspection and post the verdict.
THANKS AGAIN!!!
Jan Bauer
70 Mach 1

 

[fordnut]

have you checked the wires from the headlamp dimmer switch? It runs in a groove in the floorpan under the clutch pedal. Could have a bare or broken wire that grounds out when you push clutch pedal on top of it...just a thought....good luck with this pain in the A$$.....

 

[JBAUER4363]

After a box of fuses I have found that its not clutch related. The fuse blows when I rev up the engine! Moved dimmer wires ( they were right under clutch) pushed in clutch at idle everything OK think I got it but started to back out garage rev up motor and fuse blows!! Tried it again not moving and rev up fuse blows.
Anyone heard of this? Could 25 amp fuse be too low or alt putting out to much juice?
Cant stop now going to get more fuses!!!!!
Thanks for the help working through this problem!!!
Any more ideas?
Jan Bauer
70 Mach 1

 

[Midlife]

Weird. At first, I'd have said there is a wire caught in the clutch return spring assembly (been there, done that - it was the backup light wires). As for reving the engine, I'd have to say that something is being pinched as the motor rotates under higher revs, and the only thing that comes to mind is the backup light switch, located at the tranny. Hmmm...backkup light wiring is always hot. I'd start there. BTW. which fuse blows? What's on the circuitry? Is the backup lights on it?

 

[JBAUER4363]

You may be on to something there. I dont think my back-up lights work. If I remember last time It was on lift there was something hanging out under the car and mechanic said it was the back-up light switch. He put it back where its supposed to be but I think if I hit reverse hard it pops out.
I just replaced fuse and started went through all the tests again signals, lights, clutch, etc. and didnt rev car and no blown fuse. I did this for 15 min and no problem. It was on fast idle and no problem.
Later when Its cooler Im going to attempt to drive it and see what happens. I wonder if I could unhook back-up light switch to check or then would nothing work. If anyone has removed back-up switch maybe you could let me know. I really dont care if I have back-up lights anyway.
Well at least I didnt spend holliday laying around the house with nothing to do! Ill probably have to turn this over to a mechanic but who nows.
THANKS AGAIN for all the help!
When solved Ill post what it was.
Jan Bauer
1970 Mach 1

 

[Midlife]

Aha! There are two lines to the backup light switch: one is always hot, and the other, return, line goes to the backup lights. These two lines are identical in color, and route near the clutch pedal return stop. They are also routed next to one another through most of their path. You can hook up the two lines together, but then your backup lights will always be on. You can leave the hot wire disconnected, but it must be well insulated to keep it from shorting out.

The switch is straightforward, and should be installed correctly.

 

[70_Coupe]

You don't have to keep blowing fuses to check for shorts. A good trick is to take a tail lamp and a socket, or solder wires to the bulb, and put the lamp wires in where the fuse would go. Little aligator clips on the ends of the wires are good for this to connect to the fuse clips.

Now, when a short occurs, the lamp will glow l brightness. When there is not a short, and a car lamp (like a brake light) is turned on, the test bulb will glow, but not at full brightness.

Don't be concerned, with the lamp in, in place of the fuse, your auto lights will be dim when on, but what you want to observe is your test lamp. As I said, when you get a full short, the lamp will burn brightly.

This allows you to repeatedly make the short "appear" without replacing the fuse, and if you place long wires on the test lamp, you can bring it up to where you can see it while testing for the short.

This will not burn up your wires, the max current pulled will be just what the lamp draws, thus it will protect your automobile wires.

Good luck,

Tom