Problem related to several circuits

[Jerlle]

I am a new registered member but have been around taking in information for over a year. This is the first problem I've encountered that I haven't been able to find a solution on the site for...

This weekend on a short drive home from a friend's my '74 1.8's alternator light came on. The alternator seems fine. The belt might need replacing or adjustment. However, I believe the problem is unrelated to that.

The tach no longer works properly (displays much lower RPM than the engine is running.)

The brake lights, back up lights, and turn signals no longer work.

The alternator light gets brighter and the fuel gauge and tach bury themselves at zero when the brake peddle is depressed.

The oil pressure and alternator light no longer come on when the ignition is turned to "on" but engine is not running.

The alternator light and the rest of these symptoms, save the brake light, turn signals, and back up lights to my knowledge, occur after the car has been turned on and driven a short ways (possibly after a certain RPM is exceeded).


My guess is that there is a short somewhere and that I will need to take the dash apart to find it. I just wanted to drop this issue here to see if anyone had any sage advise before I start ripping out the electrics of the car to find the problem.

I appreciate any help. Thank you.

[Dave at Pelican Parts]

Fuse #8 has popped. All of those are fed by that fuse. Sometimes the fuses can pop without looking like it on first inspection; if you remove a popped fuse the metal will usually fall off it onto the floor in two pieces.

Why did it pop? That's the next question. You definitely have a short somewhere to make the fuse blow.

--DD

[Jerlle]

Thanks for the reply.

I looked into your suggestion a little more and it appears for 1974 most of everything I listed off did share a common fuse but according to this site it is the #9 fuse. Could be wrong. I will go through the fuses again and check them more closely. What you say makes sense being that this all happened at the same time and they all share that fuse.

[Jerlle]

It ended up being the fuse. I must not have noticed it when I checked them before.

Now that I think about it I believe the short is in the front blower controls. I remember turning it on one cold morning (it has always make a crackling noise when coming on, not good I know) and then it wasn't running anymore.

Thanks for the help.

[Dave at Pelican Parts]

Oops, wrong fuse number.

--DD