I would like some direction in regards to my 1972 240Z, this problem doesn't happen all the time gauges will be fine for weeks than the fuse blows, also the T.S. and Hazard flashers are on this circuit.
The turn signals always blink really fast is this normal. I suspect maybe a faulty relay?

 

Is there a pattern to when this happens? Are you using the turn signals? Does the car hit a bump? Was the car ever an automatic? Has the wiring been modified?

The only "relay" in the circuit is the flasher. The speed of flashing can vary with things like voltage, using LEDs, etc. Have you measured the voltage to ground at that fuse (with the car running)?

 

Hi Steve
No it's random, I replaced the flasher it slowed the blinkers down to what I think is normal, all the bulbs are good but like you said the speed will vary on which type of flasher is used. I drove the car for about an hour blinkers worked fine. I was about 2 miles from home and wham there it goes again blown fuse wasn't using turn signals my gauges just go flat and quit working. Sometimes when I put in a new fuse it will blow right away or two weeks later. My friend who I bought the car from said he never had a problem the car is 100% original with only 56,000 mile on it. I pulled the center console today to take a look at the fuse block everything looks good. My assumption
is that the short is before the blinker switch does that make sense,since the blinkers work and doesn't blow when the signals are in use. Could a defective sensor such as a temp or oil pressure sensor blow the 20amp fuse? Any thoughts would be appreciated.

Regards
Dan

 

From what you describe, I would first suspect a wire has been spliced or the insulation is damaged. In that case, the wire moves around and comes into contact with ground. If there is an aftermarket stereo (quite likely) or no stereo (where an aftermarket unit has been removed), you may want to look around inside the center stack to see if someone tapped into the green wire for a switched power source for a stereo.

 

HI Steve
I forgot to note the car has a four speed transmission.

 

Steve
The original radio and speakers are in the car and still work lol not the best sounding but original, I agree possible insulation is rubbed thru, finding it is the problem since its so intermittent.

 

But did it come from the factory with a manual transmission? The automatic transmission cars had wiring that came off the same fuse. If someone wasn't careful during the swap to a manual, something could have been left exposed.