[soundwave89]

Can someone help me make sense of this? I would start to diagnose the problem, except I don't know where to start! None of this is logical, unless the HVAC system on this trooper is different from any I've seen before.

So my problem is, whenever I turn my fan on, my idle drops. At a stoplight it feels like the truck will shut off, the rpm drops below 1000, then I switch the fan off and the idle goes up to normal. Whatever setting the vent switch is on doesn't seem to matter, although I usually keep it on defrost.

So what's the deal here? I know my alternator and battery are good, and the fan works fine on all three speeds. No other electrical problems that I am aware of, and the truck runs fine other than the cold start valve still being broken.

 

[CatFuzz]

Check your grounds. Especially the ground for the fan motor. A bad ground can cause an excessive power draw and when that happens it over loads the alternator and drags the engine down.

 

[johnnie59]

X's 2 Also, having the A/C turned on can cause this because of the extra power drain on the engine to turn the compressor.

 

[JLEMOND]

Can someone help me make sense of this? I would start to diagnose the problem, except I don't know where to start! None of this is logical, unless the HVAC system on this trooper is different from any I've seen before.

So my problem is, whenever I turn my fan on, my idle drops. At a stoplight it feels like the truck will shut off, the rpm drops below 1000, then I switch the fan off and the idle goes up to normal. Whatever setting the vent switch is on doesn't seem to matter, although I usually keep it on defrost.

So what's the deal here? I know my alternator and battery are good, and the fan works fine on all three speeds. No other electrical problems that I am aware of, and the truck runs fine other than the cold start valve still being broken.

CHECK THE IDOL UP SOLINOID ON THE PASS FENDER PANEL, IT HAS TWO VACC HOSES GOING TO IT A ND I 2 PIN CONNECTOR THAT IS SUPPOSED TO CREAT A AIR BYPASS AND IDOL THE ENG UP ANY TIME THE COMP ENGAGES .

 

[soundwave89]

You're talking about the solenoid that's somewhat in between the battery and washer fluid tank, correct? And has two spade connectors coming off it? Mine reads 0 ohms.

Plus, one of the wires (the one that doesn't ground on the body) goes down to a wiring connector, but instead of being connected to the connector, it's hooked up via a wire tap clamp. And I can't find where the connector is supposed to plug into.

Also, can anyone tell me why my a/c compressor is made by ford? Is this normal or was mine pulled from a salvage yard?

 

[JLEMOND]

You're talking about the solenoid that's somewhat in between the battery and washer fluid tank, correct? And has two spade connectors coming off it? Mine reads 0 ohms.

Plus, one of the wires (the one that doesn't ground on the body) goes down to a wiring connector, but instead of being connected to the connector, it's hooked up via a wire tap clamp. And I can't find where the connector is supposed to plug into.

Also, can anyone tell me why my a/c compressor is made by ford? Is this normal or was mine pulled from a salvage yard?

SOUNDS LIKE YOU HAVE AN AFTERMARKET A.C UNIT ON THERE , THE CORRECT FAST IDOL SOL, HAS A WHITE PLUG IN CONNECTOR , SOUND LIKE THE ONE YOU HAVE IS ABOUT 1=1/14 IN SQUARE AND 2 PUSH ON TERMINALS DEFINATELY NOT FACTORY. ONE OF THE LEADS SHOULD BE HOOKED TO THE COMP CLUTCH WIRE AND THE OTHER GROUNDED .

 

[soundwave89]

Here's some pics, maybe you could tell me what I'm dealing with?

 

[JLEMOND]

Here's some pics, maybe you could tell me what I'm dealing with?

DEFINATELY AN AFTERMARKET COMP, SANYO/SANDEN 508 FROM THE LOOKS OF IT , NOTHING REALLY WRONG WITH THE COMP THEY WORK FINE , BUT THAT SOLNOID IF THEY ARE TRYING TO USE THAT FOR AN IDOL UP SOLNOID IT IS NOW WHERE BIG ENOUGH TO PASS ENOUGH AIR TO MAKE THE ENG COME UP IN RPM UNDER A LOAD , THE HOSES ARE TOO SMALL IF THAT IS WHAT IT IS BEING USED FOR, THAT WHITE WIRE CONNECTOR IN THE ONE PIC IS WHERE THE FACT FAST IDOL SOL PLUGS IN AND THE 2/8 DIA HOSES GO OVER TO THE INTAKE MANIFOLD , ONE HOSE GOES TO THE THERMO VL ON TOP OF THE THERMO STAT HOUSING AND THE OTHER GOES TO THE PIPE ON THE UPPER COMMON CHAMBER , WHAT YOU NEED TO DO IS TAKE A VOLT METER AND HOOK IT TO THE TWO TERMINALS ON THE WHITE CONNECTOR AND SEE IF POWER IS APPLIED WHEN THE CLUTCH IS ENGAGED AND GOES OFF WHEN THE CLUTCH DISENGAGES , IF SO THEN YOU NEED TO HOOK UP THE FACTORY SOL , IF YOU HAVE POWER THERE WHEN THE CLUTCH TURNS ON AND OFF
YOU SHOULD HAVE FAST IDOL IF THAT SOL IS ANY GOOD, THE FACT SOL IS ABOUT 40.00 WITH THE HOSES , BUT YOUR MAY BE WORKING , IS THERE A KNOB ON IT THAT WILL TURN ,SOME OF THOSE THINGS WERE ADJUSTABLE TO VARY THE IDOLING SPEED ,, THE FACTORY UNIT IS NOT ADJUSTABLE IT ONLY LETS IT RUN AT A PREDETERMINED SPEED .