New member, just picked up a 00 Tracker 2liter auto. The 4WD light isn't working,  I swapped the bulb with known good ones and even probed the cluster harness and have no power to the 4WD light. 


I can hear the pump kick on when 4H is engaged and I have axle bind up when making tight turns in 4L. What would the next step be to test the circuit?

The switch on the transfercase is probably faulty

Actually - no - if the switch on the transfer case were faulty, the 4WD controller would never engage the pneumatic freewheel mechanism in the front axle - he's hearing the pump come on, so that switch has to be working.

HondaDNA - I just replied to your thread over at the Suzuki forums in some detail - what color wire to measure, what voltage to look for and so on - you should find what you need over there.

Thanks fordem, I'll hop over there and check it out.

Funny, I just bought a '99 1.6L today.
The 4wd was working, as the turned up gravel indicated, but the old owner had never seen a 4wd light come on.
When I got home I checked and there was a plug by the pump unpluged, plugged her in and "tada" the 4wd light came on. Maybe for the psi sensor to trip the 4wd light.

There's only one electrical connector there - it has three wires, black, ground; red, +12V power to the pump and pink, feedback from the pressure switch to the 4WD controller.

Very simplified, here's the sequence of events - the 4WD switch on the transfer case tells the 4WD controller when 4WD has been selected, and the controller applies power to the pump and monitors the feedback signal - if it sees the signal go high, it turns the 4WD light on, if it does not go high after 10 seconds, the controller shuts the pump off as a protective measure. Assuming that everything is functional, the pressure from the pump engages a freewheel clutch transmissitng drive from the ring & pinion to the differential.

When you shift back to 2WD, the controller shuts the pump off & opens a "dump valve" releasing the air and disengaging the freewheel mechanism