Ok I'm having all the classic short problems with my electrical system.
Tachometer does not work;

Intermitten wiper and HI setting does not work;

Horn does not work;

All lights work, im assuming my rear lights work (back-up)

My question leads to the fuses in the CPU, the (2) 7.5amp fuses have been replaced with 10amp. Does this cause any problem?

Looking at the CPU i think its the room amp and the one directly left? Well its the only 2 7.5amps.

Help is appreciated.

-Evan

 

It's not going to harm anything, or cause any problems, it's just allowing those specific circuits to draw another 2.5 amps if required. Your tach problem is caused by faulty soldering, you can tap on the front of the plastic to make it work again, but that's about it unless you feel like ripping the gauge out and fixing the solder joints. The wiper switches are doomed to failure, it cost about $30-60 to get it repaired/replaced.

 

I appreciate the promptness. The guy a bought the car from just replaced the clutch, I think the tach wire connects to this somehow but im not sure.

There are some wires I am not sure about:

1 wire in the trailing coil, its blue and yellow and has a female adapter, is this my tach sensor?

also, under the steering column there is one loose connector, its a 3 prong female adapter and it has two wires a yellow/blue, and a red/blue i think.

I would just like to know what these connect to if anything. Thanks again.

 

Nope, nothing to do with it. That's the plug for connecting a diagnostic tach. It tees off the wire between the coil and the tach. It's not normally connected to anything.
This is most likely a problem in the instrument cluster, not the wiring.

Wiper switch failure is very common on FC's, but it can usually be repaired. Click here for a how-to.

The CPU (which contains the horn relay) can also suffer from problems. Search for "CPU resoldering" for more info.

BTW, the fuses are in the fuse box, not the CPU. That's a seperate item that controls things like the indicators, horn, some warning lights and buzzers, etc.

 

It is fairly common to have the electrical problems you have. There are countless write ups on fixing them.

You can repair them yourself if you are electrically inclined or I repair the wiper switchs and CPUs (which controls the horn among other things) as well as clock/idiot panels, and Logicons (climate controls).

You will however want to replace the over valued fuses with the correct amperage fuse. The last owner probably just stuck the fuses in because he or she couldn't find the right value. ATC fuses need 110% of current to blow, so your 10 amp fuses are about 2.75 amps too high.

If you would like the wiper switch or anything else repaired, feel free to PM or email me (icemark@earthlink.net). One the wiper switchs I do replace the relay(s) with a sealed 8 amp version(s) (instead of semi-sealed 4 amp one the factory uses) for longer life and resistance to corrosion and contact arcing.