defroster sucks!!!

[PUPTLAM]

before i go tearing into my deroster/heater, does the fj40 (oct/74) defrost just suck becouse its an old truck,,,or is there a quick fix someone would like to shed some light on?

 

[Jukelemon]

If you plan on keeping your 40 a bit, take the heater and hoses off and clean/replace any seals. If the seals are bad, you lose a lot of air pressure. Really not that big of job when you get into it.

 

[PUPTLAM]

if i do this, will oit really work? i am getting just the smallest amout of air out,,,,,,i remember my dads we had to scrape ice while we were driving. he would pull over and one of us kids would jump out and scrape,,,,idaho panhandle,,,very cold

 

[FLYINGLOW]

Not totally sure that it will work in a 74, but in my 77 when the original blower quit, I put in one out of a 78. It has a little cooling tube that goes from the blower to the motor. It moves quite a bit more air.

 

[Landpimp]

they can work well, all mine do even the old 45LPB, make sure the defrost diverter is working.

 

[PUPTLAM]

when your defroster is on does it still blow hot air out through the normal heater, even though its on defrost? mine does, hot enough to burn my legs,,, the defrost tube is clear, i at least pulled that out and checked

 

[FLYINGLOW]

fix the diverter then.

 

[Landpimp]

yes some heat will still come out at the floor. Really all mine keep my front windows clear, the 82's even keep the side windows clear.

when your defroster is on does it still blow hot air out through the normal heater, even though its on defrost? mine does, hot enough to burn my legs,,, the defrost tube is clear, i at least pulled that out and checked

 

[PUPTLAM]

Diverter will be todays project, was not sure if there was hope.

 

[PUPTLAM]

i'll probobly glass off the heater outlet except two outlets for driver and passenger feet, let the rest go to the defrost,,, its all hot air in the cab?

 

[Landpimp]

also make sure you have the knob for the fresh ait pulled out, if its not its just gonna reciculate the inside air and it will not defost well.

Some of the anti fog stuff on the glass will help.

 

[PUPTLAM]

i thought it would defrost better with the warmer cabin air?

 

[PUPTLAM]

i never got your opinion on a wiring harness?

 

[IDave]

Definitely fresh air defrosts better than recirculated, as LP said. Older 40s like mine (and yours, I think) don't have side window diverters, so all you get under severe conditions is defrosting of the front 1/3 of the driver's and passenger's door windows (as well as the windshield). Can make it harder to see your outside rearview mirrors. Make sure your seals are tight, so you don't lose flow from your blower. One spot can be where the heater blower (passenger side) goes through the firewall. You can lose air there pretty easily because the blown foam insulation breaks down.

 

[froggy]

I don't know how cold it gets where you live, but here , we have COLD winters. We had 2 days before christmas at -39 cel. . I just don't drive my 1971 when it gets under -15cel. It's just never hot!!! IIRC the later models core is bigger. It surely helps...

 

[IDave]

16 below Farenheit last Wed here (guess that's -27C). Drove my 71 FJ40 in. No, it wasn't hot, but then it wasn't bad really.

 

[Landpimp]

it will be warmer but not clear the window nearly as well. OPen the fresh vent and try it again......bet it works alot better.

i thought it would defrost better with the warmer cabin air?

 

[fj40_rico]

I was having the same problem before and I heard that there is a resistor in the fan that you can bypass to make the fan blow more air. Also make sure that the valve coolant valve is fully open.

I replace my heater with a mojave heater so I never tried the resistor thing.

- Rico.

 

[dustin]

my '71 had problems getting good air to the window. turned out the gaskets that go between the windshield and the tub were warped into a "closed" position. They are an oval gasket, and the long sides had bowed in, restricting airflow significantly. I just removed them, put some house window/ door seal foam tape around the holes and it blows hard now. When the windshield gets really wet, I use a small squeegie to quicken up the defrosting too.

 

[Jukelemon]

There is a good article in tech about a fellow who took out the blower, took out the brushes and placed a spacer AND spring where there was just a brush and wire i.e. better and continuous contact. Did nothing else and increased fan speed way beyond stock rpm. Moreover, his blower completely stopped working so you can imagine the total impact of that mod.

Not to be a smart ass, but are you sure your def. ducts are hooked up to your window vents? My 76 had ripped ones right at the top. A quick glance would not have indicated this on mine.