Heater hose routing

[vtwinsport]

Hi all,
I recently upgraded to electric fans and had to move heater hoses. My old 5/8 supply heater hose was on the intake manifold. Now its in the water pump because the fan temp switch is in the intake. Couldn't mount it in the head like I wanted. See pictures.
Thing is, I don't get any heat now until the thermostat opens and I'm running 180 on the gage.
Is this normal?

[ray_mcavoy]

Hi vtwinsport,

No, that heater operation isn't normal due to your house routing.

Hot coolant is supposed to flow out of the intake manifold, through the 5/8" hose, and into the heater core. The outlet/return of the heater (3/4" hose) is hooked to one of two locations. Most trucks have it hooking into the radiator. While cars often had it hooked into that fitting on the top of the water pump.

So basically, what you've done is hooked your heater core between the two places that are normally used as returns for the heater core outlet.

It looks like your intake manifold has a boss (between the thermostat housing and the heater hose outlet) that could be drilled & tapped to accept your fan temp switch.

Another option might be to get one of those spacer blocks that mounts between the intake & thermostat housing. They're often used to plumb coolant lines from the back corners of the intake. You could use one of the holes in the spacer for your fan temp switch. And since it would be below the thermostat, it'd be reading engine coolant temp regardless of the thermostat being open or closed.

[gchemist]

Use a smaller switch to screw into the head. Is there a water port in the rear or other front side?

[motornut]

can almost see mine on the other side,or is yours a blank

[vtwinsport]

Thanks everyone,
I moved the heater hose back and found the outlet to the right of the thermostat worked. forgot it was there.
thanks again.

[gchemist]

[vtwinsport]

Originally Posted by gchemist