FJ60 Heaters SUCK (1 Viewer)

[cruiserpilot]

I’ve got mine all sorted out. It’s a combination of finally getting the bottom reservoir in the heater
core in the cabin cleaned and flushed completely.
In the above post all I have to add is I used a shop vac for air pressure. Make sure you don’t use more
pressure than the system can handle! I wouldn’t put high pressure compressed air thru there,
be careful. I see you said you used a water/air system flush I just wanted to post up a caution.

 

[g-man]

I think the factory clamps were those band clamps with the sardine can clamp type (I am not sure the correct term here). Maybe they different things here on different years. Shot of mine with what I think are the original clamps going to the bottom of the heater core counter to what that diagram shows. I think thats a mistake in the diagram. Seems like there wouldn't be room to route the hoses that way. My '84 with the sardine band clamps:

View attachment 2581435

It would be hard to believe someone replaced this stuff in my trucks past and re-used those clamp types to do it. My guess is that they would have used the Toyota double hoop clamps. But if mine has not been replaced then its factory going to the bottom heater core pipe.

I don't think the diagram is a "mistake". Just misleading by showing the dotted lines connecting it and going right to the top ...but it's just saying to attach the hose to the heater core part. Notice there is NO line connecting the hose at the bottom to the heater core AT THE BOTTOM connection.

 

[mbx118]

Has another thought after installing a headlight harness and reading a lot of the threads on that issue. As most know, the wiring in most of these trucks is so old at this point that there’s a pretty decent voltage drop to the blower motor.

Here's an article from Fluke on it.

Diagnosing Voltage Drops Electrical Automotive Troubleshooting

Voltage drop is one of the most common electrical problems showing up in automotive shops today. This article features the symptoms of voltage drop, basic procedures and grounding tests to keep you safe.

www.fluke.com

When I measured my blower motor I had 2V drop from the + battery terminal to the blower motor and a 1.3V drop on the ground of the motor to the negative terminal. Of the 13.8V ish at idle, the blower motor was only seeing 10.5V, the rest was lost to wiring and connections. Pulling about 10 amps with the engine running and the motor on max. I tried to trace it looking at the relay box and the fuse block, etc, but eventually just decided to bypass the whole positive side with a relay.

This guy did something similar, A/C blower motor wiring by-pass. - https://forum.ih8mud.com/threads/a-c-blower-motor-wiring-by-pass.1083243/

The ground side of the circuit has the control switch and the resistor setup so you can't really bypass that unless you want to run on max the whole time. I did take out the blower control switch, disassemble it and clean up the contacts with CRC contact cleaner and emery paper, that got me about 0.5V improvement. Those control wires are a b*tch.

I then ran a 12 gauge wire with a 30 amp inline fuse from the battery terminal through the passenger side firewall to a 4 prong single pole single throw relay that I stashed in the passenger footwell. Hooked up the original blower motor wire to trigger the wire run from the battery to the blower motor. Now, the blower motor pulls 12.5-13 amps at max now. Certainly feels like it blows harder.

Already have a new evaporator so I'm not improving airflow there. At some point I'll refoam the duct work, but that really all that's left.

 

[elripster]

Make sure the blower motor isn't rotated. It can be mis-clocked on install which will really reduce air flow through the vents. It's easy to check, just loosen the 3 nuts, rotate it 120 degrees and test. The strongest vent flow is the right position.

Frank