90 Amp Alternator Swap
(Improved A/C Delete)
Upon acquiring my 84 Rabbit diesel, I was plagued by belt tension issues caused by a less than genius A/C delete performed by a previous owner. After exhaustive searching, I was unable to find any serviceable methods of tensioning my alternator belt. The three most common solutions on the net were to:
- Use the factory (A/C Equipped) tensioner with a non-A/C alternator pulley. This proved problematic because the increased distance between the alternator and crank pulleys caused the belt to thrash about so badly that it ate a drive belt at least once per tank of fuel. Belt life in this configuration was less than disappointing. The position of the belt also made my plans to install a tachometer pickup in the timing cover impossible. Unacceptable.
- Find an alternator bracket, tensioner, andalternator from a non-A/C MK1. This proved impossible (I couldn't even find a PICTURE of one to show you). Any MK1 I managed to locate in any salvage yard, ANYWHERE that didn't have factory A/C had already been stripped of the parts needed . It also limited me to a 65 amp alternator (I demand more power)!
-
Use an alternator
and bracket off of a 2.0L ABA (Found in the Golf GTI…forget which
years) along with the proper serpentine crank and water pump pulleys
and a clutched alternator pulley (to protect the nose on the
crankshaft from backlash caused by letting off the accelerator).
INAof vwvortex.com offers this kit that includes the bracket and alternator for $300 USD (pulleys needed to make the swap are an additional $100+). Though this option eliminates tension issues, gives the option of either a 90 or 120 amp alternator, and looks great under the hood, it's well out of my financial reach.
- Option 4 (My first attempt) uses the same alternator as the final solution (90 amp from an 85-92 Jetta 1.8L with A/C) along with a universal small-block Chevy alternator tensioner (available at Auto Zone). This option worked...kinda. Due to a somewhat flawed design (my fault) one had to re-tension the belt every few days. Click here for more detail on the setup. (Not a recommended long-term solution).
If you find yourself in the same situation and are somewhat mechanically inclined, I have the solution!
I have devised a setup that uses a 90 amp alternator, the factory A/C Alternator bracket, a non-A/C pulley and a little ingenuity that uses a shorter belt than option 1, is humanly possible (unlike option 2), and fits within the budget of a full time student/nearly full time parts specialist. The conversion requires no special tools, uses an alternator which is stocked at most parts houses, requires no tools to change belts, and works with the shift light in 82 and up Volkswagen diesels (see my "How to add a "W" terminal to your non-W alternator" article).
Note: This will not work with the A/C condenser in place, it must be removed to provide clearance for the alternator.
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