This solid state device allows you to connect your engine alternator directly to both batteries without fear of overcharging, or of one higher-charged battery discharging into the other lower-charged battery. Using this unique device, the batteries are electrically isolated from each other. Both your batteries are always automatically being charged whenever the engine is running. Rated for up to 70 amp alternator. For 6, 12, 24, 32 volt negative ground systems.

Permits use of isolators with up to 50 amp chargers. For alternators without diodes, order required isolator plus the R-Kit part U-3059.

How to determine if your alternator has isolation diodes: With ignition (keys) "off" and battery switch (if you have one) "on", measure the voltage between the reg/aux/61 terminal and the engine block. Set meter on 20 volt scale. If voltage reading is zero (0), there are no isolation diodes.

Note: Guest isolators are not recommended for use with engines equipped with the following alternators: Neihoff, Delco 10-SI series, Hitachi LR 135-31 type 110 or type 106, Leese-Neville JB series.