No heat

[jlb]

Hello everyone I'm new here great site well I have a couple of questions I have a 1990 bronco 5.8 1st question I have is my temp gauge drifts back and forth while driving but while it's idling it's fine but I have no heat I replaced water pump radiator and thermostat and still nothing could it be system needs to flushed out and also what year doors and tailgate can I go up to can anyone help I'm at a loss.

 

[Krafty]

I assume you mean you have no heat in the cab? if so then feel your heater hose lines that run from the front of the engine to the firewall on the passenger side. feel the hoses when the bronco has warmed up. Both hoses should be close to the same temp as the upper and lower rad hoses. if one hose is hot and the other is not then you likely have a block in your heater core. If so then you can try reversing the coolant lines then switching them back to try to flush it that way (changing the direction of flow might clear it out),if that doesn't work then its up to you, you can replace it or try to unblock it by disconnecting the hoses and blowing some compressed air into it, this can be risky because if you over pressurize the heater core it will likely spring a leak.

 

[miesk5]

yo,

As KRAFTY Advised

& then, if both heas\ter hoses are hot;

Poor Heater/Defroster Performance in Engine Coolant Concerns TSB 93-24-08 for 84-94 Bronco, F Series, Aerostar, Econoline & many others;

Blend door operation, Check blend door for binding and proper operation;

Mode door operation. Check mode door for binding and proper operation.

Blower fan operation, Check blower fan for proper operation and control.

Heater core plugged, Flush cooling system.

Coolant level, Check level in radiator and coolant recovery reservoir.

Leakage, Check for leaks using pressure test.

Thermostat operation, Check Thermostat. DONE.

most likely your problem is going to be the blend temp door inside the HAVC box. The door is hinged by a pivot that wears out and breaks then it is not forced into the hot air position by the cable.

The easiest way to see it is to fully lower the glove box, pull the ~8 screws from the heater core cover, & look inside to the L (driver's side). You'll see the cable & control lever (in top L of 2nd pic) as soon as you fold the glove box down, so inspect it first. The 3rd shows the whole cover - it's the large section in the top center with tiny white numbers inked near its bottom edge. The cables are visible, too...The diverter door (panel, defrost, floor) is totally independent of the blend door (hot/cold), and it's vacuum-operated, so it'll always be slow. Concentrate on the blend door for now. pull the cover & look at it..."





Core Replacement in an 89 5.0

Source: by Brahma502 at http://www.supermotors.net/registry/15076/67893

As for a new Core; iggie AZ cores since I have seen some quality isse w/them lately.

Try NAPA, oreilly's; Murray brand. Four Seasons is good.

 

[jlb]

Thanks for all the advice guys Iwill be heading out to work on it in a few will give feedback