'92 Bronco Heater problem
Thread Starter
|
New User
Joined: Dec 2011
Posts: 2
Likes: 0
'92 Bronco Heater problem
I own a 1992 Bronco 5.8 L engine. With the cold weather setting in a decided to fix my heater. I checked the thermostat first. Once I pulled it out I saw that the thermostat stayed open so I thought that that was the problem. I replaced it with a 160 thermostat instead of the 192 that I had before. Once everything was in place I tested the heater & I could only feel a little bit of heat and not like how heater should be heating. It also took a while for the heated air to kick in. Then when the truck is moving the air isn't blowing warm at all. I'm am stuck on what I should do next. Should I check the heater valves or what should I do? Thanks.
Last edited by Karolito890; Dec 7, 2011 at 03:18 PM. Reason: title
Postmaster
Joined: Jun 2001
Posts: 2,809
Likes: 3
From: Loveland, CO.
Naturally it is going to take some time for a cold truck to warm up enough to make heat. Changing to the 160 thermostat isn't going to help your situation, it will only make the problem worse. It might make it feel like you are getting -some- heat earlier, but in the long run it's only going to cause problems and it can also mess with your EFI system. I'd go back to the 192. If the vents stop pushing out any air at all when the truck is moving then you have a vacuum leak in one of the lines that controls the vents. There are very small, semi-rigid colored vacuum lines that go from underneath the hood to inside the truck. A small leak in any of these can cause the problem of the vents not pushing air once the truck is on the move and using vacuum. Do the vents blow air at idle and then stop blowing when you hit the gas to drive? Is that what you are saying? If so, then that's the vacuum problem. Also, look at the heater control valve under the hood while someone moves the control from cold to hot. It should move back and forth. If it doesn't then it needs adjusting or replacement; but that would not cause the problem of the vents not pushing air when you hit the gas to drive.
Thread Starter
|
New User
Joined: Dec 2011
Posts: 2
Likes: 0
You might have a point on the thermostat. As for the vacuum I dont think there is a problem with it. I checked the lines under the dashboard where the vacuum is and also the direction of the air changes fine when I switch the ****. As for the air, the air blows fine. When the truck is idling it blows semi-warm air, but when the truck is running it does not blow any warm air at all. Just cold air.
Posting Guru
Joined: Dec 2004
Posts: 1,023
Likes: 0
The vaccum-controlled blender mechanism is under the hood, on the passanger side of the engine, up near the cowl (far upper corner). Check the vaccum line feeding it very carefully. This is where most leaks occur.
Hotshot
Joined: Jul 2002
Posts: 14,285
Likes: 12
From: Bend,OR
you have to run a 195* tstat on our efi rigs. the computer expects to see that temp to function properly otherwise it will run rich causing excessive fueling and pour mpg. if gone for to long will have more issues.
Senior User
Joined: Apr 2011
Posts: 351
Likes: 0
From: Fairbanks
I had a similar problem in my 94. If I switched to vent, I would get a quick blast of hot air in my face then go cold almost immediately. I found out there is an adjustment you can make to the blend air door cable thats located right behind the glove compartment door. In my case my cable was out of adjustment and would not close off the cold completely. When I switched to vent real quick, the door would slam shut, but then open slightly. I found the adjustment procedure in AllData i think.
Post Fiend
Joined: Nov 2011
Posts: 8,908
Likes: 1
From: Algona, Washington
Trending Topics
Posting Guru
Joined: Apr 2005
Posts: 2,018
Likes: 0
From: Longview, TX
Heater
1. Use only a 195 degree thermostat.
2. Disconnect heater hoses from the heater core at the firewall. Hold garden hose to core tubes to flush both directions..not very much pressure please. Leave these off for step 3.
3. Remove glove compartment. Remove about six screws covering the heater core. Inspect heater blend door closing while turning the **** and adjust if needed. Remove sausage and popcycle sticks and other trash. Decide if you want to spend $25-30 for a new heater core as it just lifts out after cutting the RTV around the tubing on the firewall.
4. Replace all the plastic vacuum hoses under the hood with 3/32'" rubber. A hole the size of a pin head really makes a difference. Start with the white one by the hood hinge. You will eventually replace all the plastic ones.
5. Get a MityVac tester and test the check valve (Tee shaped thing) on black plastic hose under hood near heater-A/C box. The check valve holds the vacuum in the controls high when the engine vacuum drops low under load.
2. Disconnect heater hoses from the heater core at the firewall. Hold garden hose to core tubes to flush both directions..not very much pressure please. Leave these off for step 3.
3. Remove glove compartment. Remove about six screws covering the heater core. Inspect heater blend door closing while turning the **** and adjust if needed. Remove sausage and popcycle sticks and other trash. Decide if you want to spend $25-30 for a new heater core as it just lifts out after cutting the RTV around the tubing on the firewall.
4. Replace all the plastic vacuum hoses under the hood with 3/32'" rubber. A hole the size of a pin head really makes a difference. Start with the white one by the hood hinge. You will eventually replace all the plastic ones.
5. Get a MityVac tester and test the check valve (Tee shaped thing) on black plastic hose under hood near heater-A/C box. The check valve holds the vacuum in the controls high when the engine vacuum drops low under load.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread
Thread Starter
Forum
Replies
Last Post
86fordguy
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
6
Dec 24, 1999 10:35 AM
