Transfer Switch Hi and Lo Range (Pic on left)
Chevy Tracker, Suzuki Vitara, XL7
Hi Transfer Switch on Top and Low switch on side.
Access it inside the vehicle remove shift console. or lower transfer case.
Test - ALSO READ PCM - HOW IT WORKS ON TESTING PUMP PAGE.
Before removing the switch, Test wires before and after the switch to be sure it's the switch and not a wire connection. You want to test while in 2 wd and then into 4 wd to make sure the switch is making a connection and disconnecting, same with 4 WD Low
TEST AT VEHICLE PUMP PLUG - UNPLUGGED FROM PUMP (SWITCH STUCK IN ON POSITION?) DO TEST IN UNDER 10 SECONDS.
Key to on but leave in 2WD. Test the RED. Is there power at RED? If yes, likely switch is stuck on. We sell switches in pairs for Auto Trans (Hi & Lo), if One is bad the other not far behind.
NO POWER AT RED IN 2WD - CONTINUE
KEEP TEST UNDER 10 SECONDS -
Key to on, put into 4WD - Is there power to the Red? IF NO, maybe switch not connecting or bad wire. Also try in Lo Range.
AT THE TRANSFER CASE PHOTO HERE OR ON TRANSFER CASE PAGE -YOU SEE THE SWITCHES.
At the switches, pull on the wires and see if One pulls out. You can gain access either removing the shifter / e-brake, or by lowering the Transmission/ Transfer case.
Unplug the switch plug and shift in or out of 4WD to test if good connection.
POWER TO PINK WIRE - This represents an ECM Override (ECM is in safe mode). A correctly functioning system will not have power to the pink wire when unplugged under 10 seconds or in 2WD. Avoid test longer than 9 seconds without pump plugged in, or with pump plugged in but no evidence of 4WD light. The replacement pump will clear the system unless you have additional problems, then it will damage the replacement pump.
USE CONTACT PAGE, provide clear coherent details so we can get our professional be up to speed HEY.
WEBSITE DOES NOT DISPLAY WELL ON PHONE, UPPER LEFT CORNER OF PHONE TO SELECT A DIFFERENT PAGE FOR PARTS, TESTING, CONTACT, ETC
FOUR WHEEL DRIVE DIFFERENTIAL TEST ActuatorPumpRepair.com
Picture ref: Tracker, Vitara, Early XL7
4wd works in hi or low but not both.
The Hi and Low Transfer Switchs are independent of each other. You can have a bad Hi transfer switch with no 4 wd and find that it works in low range to get home safe.
Testing the Differential Chevy, Suzuki
Jack front of vehicle off ground and put on jack stands. Turn both FRONT wheels at once and they should turn freely. If your Actuator Pump is good you may be using it for the test. If using alternate air pressure source, find where the rubber tube goes to the diff. it's at the bottom of the diff facing the rear and at lowest point of pumpkin (or hook in where pump hose attaches). Put pressure pump with gauge on it, or use a bicycle pump with gauge, or actuator pump. TURN KEY ON and Put into Four wheel drive. Pump 5.4 - 8 lbs into the differential and see if it holds the air. (The human mouth can't produce 5 - 8 lbs). It must maintain 5.4 - 8 lbs. Turn One wheel and see if the other wheel turns in reverse. If yes the actuator is engaging. Take out of 4WD or Discontinue the air pressure and turn wheels, only one wheel should turn (test with actuator air pump to be sure air pump is releasing the air, if it doesn't release then you have a big problem with the pump).
Put into 4WD and Reengage the air pressure to the actuator. Turn both wheels forward at the same time and it should lock into four wheel drive to where you can't turn the wheels. This is limited slip diff and not posi traction so just turning one wheel will cause the other side to turn opposite. If the wheels are able to turn both forward to where the front drive shaft is turning then the diff is working but you aren't engaging in the transaxle.
Diff holds air but won't engage
Skill Level and fire extinguisher Required for safety and I am not recommending this procedure. Front wheels on jack stands. Older Differentials can get gummed up with old nasty oil. First hopefully you tried changing the gear oil (90 - 140 wt). Unscrew the filler bolt on the diff to allow pressure to release without question. Using a heat gun but not that close, put the heat to the lower front part of the differential for an hour. You want to heat the oil inside so the old oils break down and lose there gummy grip. This test isn't fool proof and far from guaranteed to work but holds merit to doing nothing. Extreme caution is necessary as you don't want to ignite anything.
After it is plenty warm remove the heat. Engage 4WD and turn the front wheels by hand as described in TESTING DIFF, hopefully it locks in. If so, do it a few times. If not, using a bike pump take the pressure up to say 10 lbs and see it it likes that. If 4 WD is achieved, put the oil bolt back in to the diff. drive the vehicle around In and out of 4wd then change the Diff Oil and remember me come pay day.
RUST OR BLOCKAGE IN STEEL AIR TUBE
Less common but we have had occasions where Rust built up and created a blockage where air can't pass through. Unplug the rubber hose from both ends and blow air thru it.
ALso, take a piece of Trimmer wire and push it up into the differential tube looking for a blockage. Blow it out, you don't want dirt or rust to release back thru the air pump.