Electrical Connections.  (missing, unplugged?)    
G16A/B  only. Sidekicks and Trackers 89-98'.

All cars made have extra connectors,  that are for UN USED (not opted) when new. ALL CARS MADE.
The real FSM book covers every where in the huge section called schematics, and the harness pages, and each connector is shown on the connectors pages, with color, shape and pinout.
Zero guessing, with the FSM. (factory service manual) If using a 10 year coverage auto store book?, this is hopeless to the extreme.

I can not predict what any  wild and woolly  PO (Previous Owner ) cutting up the ECU /EFI primary wiring to install Alarms, Remote starts, or Audio.
If he cut those wires, correct that first.  (solder and heat shrink tubing repairs, lasting quality repairs...)
More facts,  the harnesses are different for ( A/C option, (an add on harness) Cruise , factory alarm. (rear washer?wiper) 2doors, 4doors,  3/4/5sp transmission, 2wd  or 4wd.
All are different. as is Federal , California and Canada wiring... all different. (I have the factory part numbers for each.) and different outside the USA. (all are and called Vitara there.)
We get lots of questions about discovered electrical connections, that are not connected.

First off, there are over 15 options on the car, and any can be missing or just not present , (even electric mirrors)
In 1996 Suzuki sidekicks had 48 main harnesses, and 12 engine harnesses, but if they made a unique harness for all permutations, the car would be why too expenisve.
They did not use every permutation.  Ergo , extra connectors are a reality.
There are harnesses for every country made.  (laws dictate lighting and even wire colors in many countries) (even autoleveling head lamps , in EU)

My list.   Found in Engine bay harness, or in DASH.   By the way, GM/GEO the dash glove box door sticker shows all options, AS BUILT.

All parts are in the BAY and or CAB . unless marked CAB. for cab only, below. Talks ,means Communicates with...
  1. A/C  (HVAC option)  ( this is a factory add on harness  ) see here for what is added at the factory. (half removed is it by PO? was it?)
  2. The A/C even talks to the ECU. so there are wires from A/C to the ECU,
  3. A/C fuses and relays, missing near and in  fender fuse box.
  4. Doors,  the 2 door is wired completely different than any 4 door, and the latter has more options, the 4 door fuel  pump is gounded INDOORS ! unlike any 2 door.
  5. The rear window pump option and rear wipers option,  car with both, has special water  tank and 2 pumps and 2 power feeds to said pump.  My 4 door with no washer, but  has the small hose running front of car to rear. and is totally useless. but very present.  (4dr, 97 and not opted rear wiper... )
  6. Cruise control   (cab and bay locations) It has a controller under the dash. and  slave motor drive near the Throttle body , throttle (cable driven)
  7. Elect Door locks   (cab)
  8. Elect windows (cab)
  9. Lots of EGR changes in 10 years.  even added or missing, EGR VSV2 valves.
  10.  95 mid year change from 4 port to mono port EGR with added rear  of engine VSV valve (called the EGR check valve) For sure on all 96+ cars.
  11.  97  new EVAP 2 level system with lots of extra parts,  end to end.  (gas tank evap is complex starting in 97)
  12. Options of 3 different transmission and wiring.
  13.  2wd or 4wd ? yes, that to changes the harnesses and for all 3 transmissions.
  14. All years, had options HVAC, of Japan or CAMI,  designed heater systems.  (CAB) Do not order parts with out knowing ( CAMI /Japan or not) fact !
  15. 98 some heaters have the push button dash controls, option. (CAB)
  16. ABS (anti lock brakes)  (extensive ) {usually a unique harness  RWAL and other early funky ABS , some years just have RWPV (simple level valve at rear)}
  17. Power mirrors.  (cab)
  18. DRL (daylight running lights found in CANADA) HEAD LAMPS.  varies by year and country the introduction and exact parts vary by same. (and a hidden right front finder RESISTOR)
  20. YES, THE CIG LIGHTER.!  (cab) is an option.
  21. Some counties have auto-leveling head lights.  EU has them.
  22. The EGR varies by year and generation in USA and by  FEDeral or CALifornia type.  Do not mix them up.   EGR thermal probe or VSV missing.
  23. My ECU has missing pins/wires. Ok , that can be very normal,  if with out A/T , no Calif EGR,  The ECU also TALKS to the 4 speed A/T  so if no 4sp, missing pin.
  24. There are more options but I can't thank of them now.... more later...
See missing or optioned in or out, , ECU pins here.

Suzuki changed the DLC location  5time 1989 to 2004.  (then deleted it)
We see crazy PO's (previous owners ) that on a CALIF  car (or 95 cal/fed) removed the Thermal sensed EGR main and put on the illegal OLD FED EGR.
They abandoned this 2 pin connector.  CODE 51  1989 to 1995.

Below , This 2 pin connector, above the TPS, is  the PO using say a 1991 EGR main on a 1995 car,  Illegal but is missing the EGR thermal probe, rendering it dead.
The hood sticker (look at CAL here)  look upward clearly states if car is FED or California, the missing word CAL on said sticker makes car, a FED car.(or Canada words?)
Don't mix up EGR parts between FED cars and California cars.  (or exhuast parts)
This PROBE device is not present 96+  the below is a missing sensor connector on a 95.   Plug red arrow sensor  into connector at left.  Done.
This is the Calif, EGR thermo sensor, used on all early EGRs sold in Calif and later all Sidekick in 1995 and then ended for ever after 95.
I call this a Calif. sensor because it was first used there.  ( the years the ECU has a Calif pin (A4 pin 8v) to tell ECU is Calif car, on other years, the ECU is Unique. (16v)
The below 16v somone used the wrong EGR and the EGR thermoprobe connector is missing. DTC code 51 for ever. 
One guy , his car has no such connector, then someone put in a Calif ECU and , yes,  DTC codes 51/53, for ever.
The ECU P/N (part number) and harness and year dictate what EGR must be used.  On GEOTrackers the glove box RPO tag shows that truth ( options day1).

If you are really curious, just read the FSM , the FSM or factory service manual, for 96' is here and is free.  Most missing parts or issues can be sorted here.
A used book on ebay is $15,  nothing expensive at all, like new cars, with $200 CDrom manuals.
Engine problems?
What to do?,  that is easy , look at all sensors on the engine , are they wired up, are all vacuum hoses present as the hood sticker on same, shows?

Look here for all the sensors and parts in motor.

Did the ECU report gross errors?  called DTCs  ?   if yes look them up and test the path it complains about first.
On the early cars, all DTC are a serious matter, the lower the number the more serious.
A Bad TPS (code 22? ,21, 44/45 ) the latter, 2 cause bad idle, the former 2 codes cause limphome mode. and horrid running..
Do not ignore DTCs !  Diagnostic Trouble codes.

If still curious?  send me the photos, and all wire colors and for sure stripe colors, if any , and ignore DOTs.
Year, 8v/16v, 3/4/5sp trans, 2wd or 4wd, 2door or 4? and if you have or had A/C? (see link above for the harness drawings)
To dangme   at   gmx dot com... (spam proof )
I will happily look it up for you...

BAY = engine bay
Cab=  is dash and doors. and left side harnesses.

ver 1  10-2-2007
v2: 4-6-2008  V3: 11/2015 , links added.