need electrical guru, bug Options

[firstknight13]

ok car runs great!!! then i notice tach not working so i pull over and replace blown fuse. turn on key pop fuse blows . i repeat and same thing happens.... i have all lights , NO turn siganals; NO dash lights; NO NO NO......
with key off and turn signal on left or right side the lights for signaling will go on NOT flash??? if you can help would be appreciated!! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) I'm not an electrician so tell it to me in simple lingo please (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

[lapuwali]

Somewhere, you have a short. Either a wire is disconnected and dangling against the body, or the insulation is split and rubbing on the body, or something is plugged in where it shouldn't be. You need to find all of the circuits attached to that fuse (wiring diagrams help here), and trace each one, looking for the problem.

[firstknight13]

i looked at the wiring diagrams and too many too choose from thought someone might know maybe a relay is stuck??? i hav'nt a clue (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif)

[john rogers]

Could be goop in the steering column area of the turn signal switch. I had that happen about 5 years ago and pulled the steering wheel and cleaned with electrical cleaner. First, I would check the connectors at the turn signal lights both front and rear to make sure there are no shorts.

[Spoke]

A couple of questions:

Which fuse blows?

What year is your car?

Does the fuse blow when the key is turned on with the lights on or off?

Did you recently do any work in or around any wires or on the dashboard?

Do you have a multimeter?

BTW, I think it is normal for the signal lights to be on continuously if the turn signal is left in the turning position. I've noticed this on my car too.

If you can see your turn signals on with the key off, then the turn signal wires would seem to be ok.

Spoke

[SirAndy]

QUOTE (Spoke @ Apr 5 2006, 05:37 PM)

Does the fuse blow when the key is turned on with the lights on or off?

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) a few things ...

first, with key *off* your blinkers don't blink. they're used for "parking lights". so that's normal ...

second, did this happen with the lights on? i know your lights were working, but did the fuse blow with the lights on?
if so, test with lights off. if the fuse doesn't blow with the lights off, i know what your problem is ...
(IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) Andy

[firstknight13]

this is great the response that is !!!! it's a 75 2.0 with dual 40 webers. fuse #9 is the one that BLOWS (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) with the lights off it BLOWS. didn't try it with the lights on i figured it was the same as the other....

[Spoke]

Hmm... My Haynes repair book lists fuses S1 to S8 and S10 to S12. No S9. Am I missing it or is there an empty socket?

Spoke

[Spoke]

OK, I found S9. Nevermind the previous post.

Spoke

[kdfoust]

QUOTE (firstknight13 @ Apr 5 2006, 04:29 PM)

ok car runs great!!! then i notice tach not working so i pull over and replace blown fuse. turn on key pop fuse blows . i repeat and same thing happens.... i have all lights , NO turn siganals; NO dash lights; NO NO NO...... with key off and turn signal on left or right side the lights for signaling will go on NOT flash??? if you can help would be appreciated!! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) I'm not an electrician so tell it to me in simple lingo please (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

I think that the instrument lights and gauges are on the same fuse as the BRAKE lights. You might want to have a look...

Later,
Kevin

[Spoke]

According to my schematic, there should be 3 wires connected to Fuse 9:

Red/White: goes to emergency flasher. Does your emergency flasher work?

Black/Yellow: backup lights, Oil temp lamp, and voltmeter

Red/White: Goes to tach, fuel gauge, oil pressure lamp, generator lamp.

Before doing any wire movements under the dash, I strongly recommend disconnecting the battery as several wires under the dash come straight from the battery without fuses or fusable links. I don't think fusable links were yet invented in the '70s. Once you have moved wires, or fuse panel, make sure no wires are touching anything, then connect the battery and do the tests below.

Remember: disconnect the battery before moving wires.

One way to isolate the fault is to pull one of the above wires off at a time. With power off and battery disconnected, with your multimeter, measure the resistance to ground of the wire. If one of the wires is a dead short (zero ohms), then you have found the fault and need to trace the fault along this path.

If you don't have a multimeter, remove one wire at a time, connect the battery and turn the key on. If the circuit still blows, it must be one of the other wires. Disconnect the battery and repeat taking a wire off until the fuse doesn't blow. The disconnected wire will be the fault. This doesn't fix it, it just finds the fault.

Also check the wires going to the reverse switch on the tranny. One of the wires is connected directly to fuse 9. maybe even disconnect these wires first and try the fuse test.

Spoke

[firstknight13]

(IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) spoke thanks i will do exactly that when i get out of work. you guys are the greatest (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) thanks ALL will let you know how i make out!!! ray

[rhodyguy]

where are you pulling power for your fuel pump from? when the engine is running, and you press the brake pedal, does the tac drop to zero and the gen light come on?

k

[firstknight13]

i have a tach now but no brake or turn signals. I do have emergency flashers too!! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) will finish in the am and of course keep you all posted!! (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[elocke]

Tach wire on wrong coil terminal?

[Spoke]

QUOTE (firstknight13 @ Apr 6 2006, 11:04 PM)

i have a tach now but no brake or turn signals. I do have emergency flashers too!!

OK, this is good news. If the Red/White wire is disconnected (my assumption) from Fuse 9, then you would not have turn signals. I assume that you have the Black/Yellow wire disconnected which power your brake lights and reverse lights.

The flashers working show another positive. When you put on your flashers, the flasher circuit and turn signal lights get powered by Fuse 11. If this is working and lights in front and rear are blinking, then this should indicate that the turn signals and their wiring are ok including the Red/White wire.

This would leave just the Black/Yellow wire as suspect. The Black/Yellow wire goes to your brake switch and reverse switch on the tranny.

Here is where a multimeter really comes in handy. Check the resistance of the Black/Yellow wire to ground. Since the only loads are the brake switch and reverse switch (also oil temp gauge and voltmeter), you should see a non-zero resistance to ground. If you don't have a voltmeter or oil temp gauge, you should read nearly infinite ohms (open circuit). If you see near-zero resistance, there is a short somewhere on this wire. Check the wires on or around your brake switch and reverse switch on the tranny.

Note: with any wiring especially 30+ year old wiring, vibration, bendings, overcurrents, and age can damage insulation causing it to become brittle and crack or fall off. Visual inspection of wiring is critical. Also keep in mind that because the insulation is so old, moving wires to look for a problem could cause insulation on other wires to crack. Be gentle with the wires and keep your eyes open for cracked insulation, burnt insulation, loose or disconnected wires and connectors.

Spoke