i just bought my truck and i know its an old girl but the heater dosnt really blow very hard it dosnt do to bad on the defrost side but when i select heat ,vents, ect it just goes from the defrost to the floor is it suppose to blow out the lil circle vents and the 2 lil vents in the middle ???maybe a lil vacume line is unhooked some where under the hood...(had a old chevy k10 like that once) i dunno any ideas??? thanks guys

 

i think that one is wire controlled not vacuum, also check to make sure that all the tubes are in place under the dash.

 

thanks ill check it all out i havnt really messed with it yet i just am trying to get some sort of idea what it could possibly be and some one who knows the system backwords and front might be able to tell me exactly what it is but ill check it out tmr any more i deas let me know thanks man

 

Not 100% but there should several hoses running to the firewall under the windshield cowl, one going to a fitting flowing from the hard lines that cool the engine, the other going to a fitting that feeds into the back of dash or through firewall. Flush each hose while having the opposite disconnected to clear the lines out of any blockage while having someone cycle through all of the vent controls and blower levels. Did that to mine and the heater has been awesome ever since

 

The circle vents on the sides of the dash only allow fresh, cold air into the cab. No heat comes through them. There isn't really much heat in these things. I mean there's plenty to warm the tiny little cab, even it if only comes out one vent, but there aren't a lot of vents that hot air comes through.

I don't remember what setting you need to be on to get heat to come out the lower center vent...I haven't been driving my truck much in the winter lately.

 

1- I have had the heater core in both my 89 2wd and 80 4wd blocked by leaves that work their way down the fresh air intake.I had to take the the haeter box apart to get to it. I hate working under the dash but it sometimes needs to be done, So any time I'm in there I check it out.
2- The round vents on my 1980 were ducted to the heat a/c system but never worked right so I just "updated" them to fresh air vents only like "83"s

 

I thought that might be right. In air-conditioning equiped models, those circle vents are hooked to something. If you don't have ac (like me), they just go straight to outside air.

 

mine dose have ac ...but the blower fan dosnt seem to blow very hard and when i swich it from vent -heat or ect it dose nothin just goes from the floor to the defrost ..but that isnt really big deal i guess i need to try and flush my heater core and then try and make sure the valve under the hood is working good i dunno bout the blower motor i would like to make it blow a whole lot harder ...maybe my blower is a lil weak how dose everyone else blower do???

 

My blower does fine. It's the lower settings that don't work as well, because I guess the resistor has to work harder to make the fan go slow. So I don't have any fan until the last two settings. The first two don't work. I get plenty of air moving on the highest two settings.

I've been meaning to replace the resistor for a long time now...

 

Same issue here. I have a/c but it's been removed. Can't post details now, YOTATECH crashes safari on the iPad mid-reply. This is my FOURTH try.

 

I have a ’86 2wd shortbed with the same issue. Luckily, my girlfriends’ dad works for a large international auto parts company. They’ve been running Toyota trucks as their fleet vehicles for more than 20 years, after describing this problem to their service manager, he admitted that the fleet trucks had several of the same problems.

1. The heater blower resisters would get condensation and corrode, effectively loosing the blower motors’ ability to alter speeds.
2. The flow valve on the fire wall would also corrode/fail resulting in the coolant flow to the heater core either be opened or closed. His remedy was to eliminate the flow valve and run the coolant full time to the heater core in the winter, or bypass the core and send it back to the block in the summer.

I’ve opted for replacing the heater core, blower motor, and the resistor. Now all I need is to get the garage cleaned out to get the parts installed… it’s a frosty 4 degrees outside this morning in Central New York

 

Cool man let me know how it works out details take pics aswell if u dont mind i gotta do somthing my heater just aint cutting it like i want thanks

 

hey, i know its been a while, but i figured i would give this a shot. my heater went out a couple days ago, i have a 98% stock 1987 toyota pickup 4x4. when i bought the truck the heater only worked on high, it would not blow anything on low or medium. when my heater went out, it first sounded like its "battery" was dying. like it would run for just a few, and shut off, then you would have to turn it off for a few, but it never blew as hard since, just barely a trickle of air. i have been tinkering with the wireing and everything for a while now, my heater does not blow at all now, except when im driving down the road, which technically doesnt mean it "works" i can to the conclusion of a resistor block. i pulled mine out, and all the porcilain looking stuff that runs across the top of the coils is crack. this seems to be my problem correct?
thanks for the insight..

 

Yes. 4crawler has a good write up on replacing the resistor, with part #'s and everything.

 

Yep, sounds like you wrote off a resistor.
Basically either that porcelain failed and caused a secondary short, or the coils inside the resistor shorted and busted the porcelain insulation. Your assessment was spot on.

 

I have an 82 PU (Actually motor home). I have the motor out to rebuild it, and I need my heat (Because I'm a biker, a bike is all I had the past few years to get around on. The phrase, "Nobody hates winter like a biker" is true!) so I also took the heater assembly out.

I completely disassembled the blower motor and greased up the bushings wiht a high quality synthetic grease. They were dry, as usualy. I'll do a writeup on that when I have time. I also soldered heavier gauge wire to the two brushes. It blows like a tornado, now.

I also used ceramic resistors in place of the "stock" resistors that I accidentally destroyed. I got the resistance mostly matched with what I had on hand. The blower motor draws, crap I forget exactly. But you need 20 watt or threrabout resistors- however I used five watts, because technically they are "Air cooled". We'll see how it holds up. As someone who has worked on electronics for thirty years, I am fairly confident it will work out.

Examining the heater core, about 1/5 of if was completely blocked as debris had been sucked into the fins. Some fins were also bent from ? I straightened the fins and will use an air compressor to blow the junk out of the clogged fins. This will no doubt affect the ability of the heater to function properly.

It's still apart so I do not know how it will work. When I got the RV the heater did not work at all (Rodents are the wiring)

Oh, and using a motorcycle cable lubricator, I also lubed all the control wires (It does not work off of vaccuum at all) and lubricated all the controls. It's *much* easier to adjust everything, now.

The vehicle was stored near the ocean in L.A so you can imagine the corrosion. And also rodents found it to be a palace to live in, make babies and defecate everywhere, chewing wires and generally having a good time.

 

Motorcylce cable lubricator? I'd be interested in this. Both my 83 4x4 and 78 camper have kinda sticky controls, and I'm afraid the extra force I'm using is going to snap the cables or levers before long.

 

Yes, I originally bought it at Harbor Freight, but I cannot find it on their website. Here it is on Ebay,

http://www.ebay.com/itm/clutch-throt...4995%26ps%3D54

I recommend the one with TWO tightening screws as it allows you control over how tight you can tighten the cable end, or the housing end.

There's a cut in the rubber seal. What you to is insert the aircraft cable portion in the cut, the push the housing tube into the lubricator. The bottom end is stepped for different diameter housings. Select the tightest one, and tighten the screws, in unison if you can, untilt hey are plenty tight.

Then, insert the end of a straw (I used Break free CLP) into the port on the side, and spray until you see oil dripping out of the other end.

It was actually much easier than lubricating a super long motorcycle cable. Lube dripped out of the other end rather quickly.

And, there's not much that requires force as far as the diverter vanes are concerned inside the heater box. So, if the controls and cabling work smoothly, it should work just as smooth when everything is back together.

I also use the Break Free to clean every joint top, bottom, and middle, as well as the wearing surfaces above and below the levers themselves (This is important).

I like my vehicles to have smooth operating levers and windows, etc.

Unfortunately I didn't take any pics of it because I did not think anyone would care! But if you want, I can help you if you want to go through with it.

 

Thank you! I will definitely let you know if I need some guidance.

 

I actually have one of those. Even though both my motorcycles now use teflon-lined cables that don't use lube. I'm glad I didn't toss the stuff! Thanks for the suggestion.