2003 GMC YUKON DENALI Engine And Engine Cooling Problems

I HAVE HAD MULTIPLE ONGOING ELECTRICAL ISSUES WITH THIS VEHICLE. STARTING IN 2005, THE EXTERIOR ELECTRONICS (I.E. SIGNAL LIGHTS, STOP LIGHTS, HEAD LIGHTS, ETC) BEGAN TO MALFUNCTION. FOR EXAMPLE, I WOULD TRIGGER THE SIGNAL FOR ONE DIRECTION AND ALL OF THE SIGNALS FOR ALL DIRECTIONS WOULD TRIGGER... EVEN PRESSING THE BRAKES TRIGGERED ALL OF THE EXTERIOR SIGNALS. THE DEALER HAD A HARD TIME ISOLATING MY PROBLEM, BUT AFTER SEVERAL VISITS, THE DEALER WAS FINALLY ABLE TO DIAGNOSE AND RECTIFY IT... THEY ISOLATED IT TO A JUNCTION BOX WHERE ALL OF THE ELECTRONICS TERMINATE. HOWEVER, BY THIS TIME, MY VEHICLE WAS OUT OF WARRANTY, SO I HAD TO COVER THE COSTS FOR REPAIRING THE PROBLEM MYSELF. MY MOST RECENT ISSUES, WHICH, BY THE WAY, SEEM TO BE COMMON ISSUES, ARE TRIGGERED BY A MESSAGE STATING, "REDUCED ENGINE POWER". THIS PARTICULAR ISSUE DOES NOT ALWAYS RENDER THE SAME RESULTS... SOMETIMES THE VEHICLE'S...

DECEMBER 2008- INSTRUMENT CLUSTER WENT OUT- SPEEDOMETER NO LONGER WORKING DECEMBER 2008- BATTERY GAUGE NO LONGER WORKING MARCH 2009- STABILITRAK ISSUES...SOMETIMES THE STABILITRAK WOULD WORK AND AT TIMES IT WOULD NOT WORK JULY 2009 TO JANUARY 2010- REDUCED ENGINE POWER (ALMOST CAUSE 2 WRECKS) COULD NOT PERFORM A DIAGNOSIS...COULD NOT READ COMPUTER. CHANGED FUEL PUMP. NO MORE REDUCED ENGINE POWER MESSAGE AUGUST 2011- WHEEL BEARING ISSUES. REDUCED ENGINE POWER (ALMOST CAUSED WRECK...BACKED UP TRAFFIC) SEPTEMBER 2011- GAS PEDAL STICKING NOVEMBER 2011- REDUCED ENGINE POWER...HAPPENS 5 TIMES WITHIN A 30 MILE TRIP. ATTEMPTED TO RESOLVE PROBLEM SEVERAL TIMES, BUT RUNNING OUT OF OPTIONS. HAVE TO KILL CAR IN MIDDLE OF HIGHWAY OR INTERSECTION TO GET CAR TO WORK PROPERLY. *TR

RANDOMLY, THE TRUCK WILL GO FROM DRIVING COMPLETELY NORMAL TO GETTING A MESSAGE SAYING "REDUCED ENGINE POWER" AND THEN IT CUTS OFF POWER. THIS HAS HAPPENED 10 TO 12 TIMES, THE LAST TIME IT HAPPENED I COULD NOT DRIVE MORE THAN APPROX 35 MPH EVEN WITH THE GAS PEDAL FLOORED. WE HAVE REPLACED THE SUPPOSEDLY DEFECTIVE PART(S) TO NO AVAIL.