Joined
·
4,000 Posts
Here's directions on how to fix your tach.
This is a simple diagram of how your gauges are made.
1. This is what the center pin is attached to inside, it's a piece of magnet that reacts accordingly to the electro magnetic field of the coils (the yellow part), thus moving it to give you the readings of you rpm.
2.This is where the center pin rests and keeps the magnet 'floating' freely within the mechanism.
The yellow part is the electro-magnetic coil.
When you yank the needle, the center pin gets pulled from the magnet and...
..in worst cases, the center pin gets pulled out completely.
Now, what happens when you insert the pin back is...
...the pin gets pushed, but you cannot achieve the space the magnet had between the coil.
First you have to desolder and get the mechanism off the circuit board and out of the housing. Then, to make the magnet floating free inside, you'll need to drill a small hole (#60 drill bit) from the back like this.
Then insert a steel pin (I used a small nail and cut it to the right length) so the magnet won't rub against anything inside.
Now all you need to do is to solder the mechanism back on to the circuitboard and you're done!
This is a simple diagram of how your gauges are made.

1. This is what the center pin is attached to inside, it's a piece of magnet that reacts accordingly to the electro magnetic field of the coils (the yellow part), thus moving it to give you the readings of you rpm.
2.This is where the center pin rests and keeps the magnet 'floating' freely within the mechanism.
The yellow part is the electro-magnetic coil.

When you yank the needle, the center pin gets pulled from the magnet and...

..in worst cases, the center pin gets pulled out completely.
Now, what happens when you insert the pin back is...

...the pin gets pushed, but you cannot achieve the space the magnet had between the coil.
First you have to desolder and get the mechanism off the circuit board and out of the housing. Then, to make the magnet floating free inside, you'll need to drill a small hole (#60 drill bit) from the back like this.

Then insert a steel pin (I used a small nail and cut it to the right length) so the magnet won't rub against anything inside.

Now all you need to do is to solder the mechanism back on to the circuitboard and you're done!