1995 Ford F150 XL, Straight 6, 4.9L, Manual Trans

I got a new radiator, so yesterday, I performed a drain-n-fill-n-flush before taking the old one out. After I completed that I drained the system again, removed the upper hose, removed the lower hose, and removed the little overflow tank line that connects under the radiator cap. Removed the fan shroud bolts and pushed the shroud back. I did not take off the shroud and fan - just left the shroud sitting on top of the engine fan blades. Then removed the two radiator bolts and slid that bad boy out of the truck.

Today, I placed the new radiator. I actually had to take the two air flow hoses off going to the throttle body. Under that was some sort of square'ish intake plastic unit that connects to the air filter box and goes out to the grill. I had to snap that off so I could place the new radiator. Once I did that, I reconnected that air intake plastic thing and replaced the two air filter box hoses.

Next, I connected the lower hose, upper hose, and reconnected the little overflow tank hose under the radiator cap. Put a gallon of green antifreeze in there and about 1/2 gallon of distilled water.

Started up the truck to let the fluids circulate and noticed the heater and vent won't work. Not blowing - not doing anything. I hear a little hissing when I move it over to defrost but turn it back to heater to off to heater, then turn fan speed to low to high and back to low - nothing.

Never been an issue before! This is my first DIY radiator replacement. I was afraid to let my truck run more than a minute or two worried that the fluids weren't circulating. I stopped the engine and removed the radiator cap and some fluid spewed out some so it's building pressure. Should I let it run for several minutes to let the pressure build back up - and is that when the heater will start to work?

I just can't imagine why the fan isn't blowing in the cab? Kinda freaking out that I must have done something...but can't imagine what?! Any advice is appreciated very much!!!

 

First of all, you were able to get the old one out, but you had to remove the air filter assembly/hoses/etc to get the new one in? I'm still trying to figure out why you had to dismantle more to get the radiator in, although the old one came out without taking those other parts out. Not arguing with you...just trying to get a picture of why that would be. Are you using a different type of radiator? Is it bigger or what?

 

First off check your fuses, both in cab and under hood. Next turn key to on position and probe the grey/yellow and black/green wires in the steering column, these are the heater power wires (1 and 2). If you aren't getting power then something got unplugged or fuse is blown. Probe the wires at the blower motor to ensure power. If everything has power the motor may be shot. More than likely though I'm guessing that you accidentally unplugged (or forgot to plug something back in) something so go over everything that you touched and look for unplugged connectors or damaged wires. You can also check to ensure you are getting power to each fuse with multimeter, try swapping around the relays with some that you know work, don't forget about the maxi fuses.

 

You disconnected the lower radiator hose and some coolant ran out of the engine block. You done the work and refilled the cooling system as much as you could through the radiator. There is still an air blockage in the engine block. You will need to disconnect the upper most heater hose from the engine to let the air purge out of the block. Those 4.9s can be a little tough to get the air purged from.

That's the scenario as I'm guessing it to be. Maybe it's me that is full of hot air and not the engine block.

 

BroncoJunkie - Well, when I removed the old radiator, I was able to clear the intake box (?) thing by tilting it out. When I installed the new one, it was a two-core radiator - much thicker than the original single core. So I tried reversing the install but could not get it past that box - that's why I had to disconnect it so I could just plop the radiator straight down. Once I did, I realized that the fan shroud did not fit this radiator so pulled it back out, went back to the Zone and got the single core radiator. Forgot to add that tidbit in my original post but don't see where it changes anything.

I must have snagged something during the process. Just going to have to investigate tomorrow.

 

You're right, FLTDriver, I probably disconnected something. I do know that I got caught on the left side of the radiator (my left side facing the engine) on a covered wire when I was trying to push it down into the mount. I had to pull that wire out of the way to finish the job. By the time I realized I don't have a blower motor going, it was dark outside and just decided to investigate more tomorrow.

The more I think of it, it's got to be that I broke a wire or unplugged something. Or could it be a vacuum line maybe? Not sure if the vent fan/blower motor is related to vacuum lines, but I would think it's gotta be electric, no?

 

Blower is all electric, the only part of HVAC in the engine bay that is vac is the blend air door actuator, which since you said you heard the hissing when turned to defrost it's still functioning, plus the vac line only comes out about a foot or so from firewall in wire loom then into the actuator (white vac line if original).

 

Issue resolved!

Went out this morning to look at what wire I hit while trying to place the radiator. It's a covered set of wires connected to a plug next to the battery. I followed the line down and behind the grill and it goes into small box bolted to the front frame of the truck. I hit this line while pushing the radiator down and had to unsnag it to finish the radiator install.

Today, I pulled the white plug apart and reconnected it, started the truck, and all of a sudden I have the blower motor going full blast again. I had to have hit it just hard enough to pull the plug apart a bit to lose connection.

Would someone tell me what this wire (or wire group) is? It obviously controls the blower motor. I'm holding an orange pick pointing to the plug I'm talking about:

 

I believe it goes to the blower motor relay box

 

Follow-up to the radiator installation: Once I got everything resolved and put in 1.5 gal of coolant and 1 gal of distilled water. Let it run for 15-20 minutes a few times one day and kept massaging the top radiator hose to squeeze out all the air bubbles. During that entire process, I'd finally leave it running and remove the radiator cap, top off the fluid, squeeze the top hose slowly and quickly, and no more air bubbles and the level remained topped off and wouldn't budge. So I assumed it was completely filled.

On my first drive with the new radiator, I took it 11 miles to the store and the needle never got off the "N" in the word NORMAL. As I was pulling into my parking space I saw smoke billowing out from under my hood!! I immediately shut the engine off, opened the door, and saw green coolant flowing down the parking lot. Great. So I opened the hood and saw that the upper radiator hose had popped off the engine! It was held in place with a pinch clamp. Thank goodness I still had my tools with me, 1/2 gal of coolant in the back and a whole bottle of distilled water. I removed the pinch clamp and put on a brand new hose clamp and cinched it down as tight as possible with a ratchet.

Hasn't come off again; however, when I started driving it again yesterday morning, I opened the hood after driving about 5 minutes and noticed the upper radiator hose was tight - tight -tight! Making me think there's air in there. Or is that normal? I had to drive all day yesterday and was afraid I'd have another blow out so I opened the radiator cap and it gushed fluid and the level never fell as it ran, so I'm sure the air is bled out of the system?

One point to note is the bucket does not have fluid in it at all since changing my radiator. Before the new radiator it did have fluid just below the "Cold Fill" line. Also, when I shut my truck off, I hear water trickling through the engine.

Am I doing something wrong?