3988IR 2227IR Instructions
Denso IR Instructions (1379IR, 2227IR, 3988IR)
Disconnect negative battery cable
Disconnect the B+ Cable from the old alternator
Remove the old alternator
Install new alternator
Connect the positive power B+ wire to the B+ post on the rear of the alternator.
If you are replacing an alternator, this post should look very similar to the one you removed, and the wire is reconnected. Make sure the wire is in good operating condition. If you have dual batteries, it is a known issue for the crossover cable to be a problem, this will cause the main battery to over-charge and the extra battery to under-charge, sometimes the wire will get hot or fail. This condition is not caused by the alternator and is not eligible for warranty.
If equipped; DO NOT CONNECT ANYTHING TO THE ROUND REGULATOR PLUG on the back of the alternator. On earlier applications there is no plug but there may be two field wires, these are not used and can be taped up and put to the side. They may have power so please tape them, so they do not short to anything. Some IR units do not have wires or plugs on the back, this step does not apply.
Connect the negative battery cable.
Locate a key-on / key-off accessory source, often in the fuse panel, and run a new wire to the alternator location. This wire should be #14 or #12 gauge and is used to signal the alternator on and off. IR Means "Internally Regulated" and this unit will work on its own once turned on and will turn off with the ignition key.
Because this unit does not communicate with the original regulator or computer the OEM charge light on the dash may or may not be illuminated, this alternator was designed to run in any vehicle and not rely on any input from the computer or OEM regulator. A volt gauge or test meter will verify it is making power do not rely on the charge light if you have one.
If you have the W-Terminal option (2227SE only) you will need an aftermarket stator signal tachometer, it will connect to the white wire on the back of the unit, do NOT apply power or make any other connection to this wire, if you do not use a tach, do not connect anything to it.