Alternator fan belt of my nissan terrano 2 gets broken frequently

Wikipedia is usually the best way to check this as it gives good information on versions and generations.

Terrano - Wikipedia

Wikipedia https://en.wikipedia.org > wiki > Terrano
Terrano may refer to: Nissan Frontier, a pickup truck; Nissan Terrano, a sport utility vehicle; Nissan Mistral (Terrano II), a sport utility vehicle ...

NISSAN Terrano 5 Doors Models by Year (1990-Present)

autoevolution https://www.autoevolution.com > Cars > NISSAN

Dec 7, 2022 - Complete timeline of NISSAN Terrano 5 Doors models and generations, with photos, specs reference and production years.

Its a diesel and didnt know the alternator controlled the RPM ,i thought it was controlled by the wire going to no3 injector on older models

At a wreckers/parts dealers/eBay/ or similar. Depending on what is broken in your mechanism it may be possible to use a more commonly available Pareto repair the meh aims, e.g. The actual motors are quite common on other Nissan vehicles. Just watch that you get a right hand side motor..they are different to the left hand side ones! Check the model numbers on the casing.....

C clip that retains axel is broken or came off. Or the axel is bad.

Go and have the computer scanned for codes. Go from there, otherwise you are just firing the parts cannon at the problem.....

The sensor is located behind the crank pulley/harmonic dampener. To replace:

1 Remove the tire/wheel and splash shield.
2 Remove the bolts, then loosen the mount bolt and pivot the side engine mount out of the way.
3 Loosen the idler pulley center nut and adjusting bolt, then remove the A/C compressor belt.
4 Loosen the alternator mounting bolt, nut and adjusting bolt, then remove the alternator belt.
5 Loosen the mounting nuts and adjusting nut, then remove the P/S pump belt.
6 Remove the dipstick and pipe.
7 Remove the crankshaft pulley.
8 Remove the upper covers and lower cover. NOTE: Do not use the upper and lower covers for storing removed items.
9 Remove the CKP sensor from the cylinder block.
10 Install the CKP sensor in reverse order of removal.

Depends what belt it is. If it the alternator belt, it will not charge the battery, and soon die and then not start. If it the fan belt will over heat. Either way determine what belt it is, but personally I would not drive it very far, maybe far enough to get it to somewhere safe off road and maybe to first repair shop, if you can get it that far. Mike Write me back and describe what belt it is, by telling me what it goes around, alternator, air conditioner, both>? fan belt>? one single belt?

Soounds like you need a new/higher amp alt.

Audi A6 (1999 fabrication year):
1. Release the fan belt tensioner.
2. Remove the broken belt.
3. Put the new belt correctly in place.
4. Set-up the fan belt tensioner.

If you specify the engine type of yours car I will send you the fan belt routing diagram!

if you dont have the diagram on the car then you will need the manual from a local auto parts place.