Hello everyone. First post!
I've been having heater issues with my 84 300 half ton van. Fan runs but only straight cold.

So far I have found a broken vacuum line running to a valve on the heater core hoses. I zip tied the valve to bypass the line until I get a new line. I'm getting flow through the heater core so I think it's the blend door? Problem is I have no idea how to get to it. And I can't find any info on it because everything from this era is on trucks.
Also, there is a fuse missing from the box labeled heater and is marked for 35 amps. I can't find a fuse for it though. I got a 30 amp but it is too long. Is it supposed to be a glass fuse or a metal one like the one below?

The controls everything is hooked up and I don't see anything leaking vacuum or a loose connections.

 

Well I looked in the stickys and found how to get to the blend door in the heater core replacement thread.
Is this probably my issue?

 

I don't see any pics in your post, I'd have thought you'd have a spade type fuse, not a glass type

 

I did not think to take pictures. I can in the morning though. Yes it is glass fuses, but one of them is a metal box. I can't remember what that was labeled as though.

 

This is why I thought you had posted a pic. What were you referring to ?

 

The magical knowledge of all ford's that I assumed everyone had when I wasn't thinking. My bad it made more sense in my head, but I see why it dosnt.

 

Nobody knows it all. If they say they do, they are lying.
I ran and raced Fords until 92 and then we raced one in 2008, which had just about zero to do with any of my previous Ford experience.
I bought a Ford van a couple of years ago and have been catching up.
Others here have far more Ford experience than I.
That said, I've been involved with cars for 90% of my life. My family goes back to the 30's in racing.

 

Yea I wasn't thinking. I would love to get into racing but I wasn't friends or family with any, and I'm Uber broke.
I do have a crazy dream of one day make this 4.9l van beat a stock 5.0 mustang in the quarter though. Not gonna happen without spray I don't think though.

 

You can't post pictures until you have 10+ or more posts.
Keeps the from posting 1 question, and never returning.......

Check out this Topic, there is a picture of the '87 fuse box, with lables, might be as close to what you have?

You'll be looking for a "glass fuse" Like this -





But.......aside from that........an '84, 30+ years old..........I'm sure the heater core is plugged up by now.........

Simple way to check is to disconnect the 2 heater lines (after draining down the anti-freeze) hook up a couple of 5/8" hoses to the heater core, and using a garden hose, flush out the heater core, the loose end of the temp hose in a bucket, and you'll see what will come out.

Your other problem is the vacuum line, you said it's not going to the heater valve?? That controls the coolant flow thru the heater core, when you make a dash selection for heat, that opens the valve, so that engine warm coolant flows thru the heater core. Some time after what ever year, they emulated the heater valve, because the coolant would sit in the heater core and cause it to plug up (read above for flushing)

Think you should get that vacuum line hooked back up first, and see if you get any warm air out the dash ducts, if not, then flush the heater core.
I think the fuse your chasing is for the AC in this era van, and not for the heat.

I think the heat/vent selector on the dash panel is cable controlled for the blend door also.

 

the vacumm line is broken so ill have ti get a new one. I zip tied the valve in the open position to test it and still no luck. Cracked the hose on the core and coolant starting flowing out so i dont think its plugged but i may just replace it ao it dosnt start leaking on me being this old.

 

I had 2 I6 , 4.9 Engines...I still have alot of parts for that engine....what do you need.....

 

Well I'll need to get that vacuum line, and once I start working I'm going to look for pre feedback carb and ignition system. I am on a shoestring budget right now though as I havnt had any work for over a month.

 

Forget about the carb.... plug that line ...It is a garbage carb ......If it does not run you have electical chit going in......I think I have a good Carb.....I need to look .... I have alot of I 6 parts......

 

With the I 6 firing order is critical.....you need that first...look at the cap / leads

 

The I 6 is gear driven ...like the 225 Dodge and most Diesels..and they are UNDER square as well...