Heater fan blows but no heat

[justgary]

2 hours ago, iliketoski said:

You know I'm beginning to wonder if it was ever hooked up at all.  I've located both plugs and neither one has any sign that it has ever been touched, (given the shape of the boat overall, I highly doubt they would ever touchup the paint on the plugs).

I have no reason to suspect the engine was ever replaced, the boat doesn't have a ton of hours on it (500), and the looks of things support that.

Any idea what size fittings I need (the hose is 5/8" ID?).  (Obviously, when I take the plugs out I'll know), I want to get them in advance if possible,  I'm thinking they are NPT with a 5/8" barb on the other end.

 

Yup, NPT and 5/8" barb. 

I also installed a ballcock in the hose so I can stop the flow of water through the heater if I need to.  I only put one on, so I can't isolate the heater per se, but I thought it was a good idea at the time.  The fact is that I never close the valve, even when it's 100 degrees outside.  The flow through the heater gives a bit of auxiliary cooling for the engine even with the blower off.  I have closed cooling, so the odds of blowing a heater core due to rot or freezing are pretty small.

Closed cooling also means that I can't use the Y fitting that came with the kit, hence the use of the electric pump.

[granddaddy55]

17 hours ago, iliketoski said:

It is the 5.7.  I noticed on the right side of the thermostat is a sensor. then on the left side (same place) is a plug in the top of the manifold.  I kept looking for something that had been reinstalled or capped, since the heater is now disconnected.  The plug I found still has the original engine paint over it.  Is this what you are referring to?

I like your mod, I want to see how it will work without the "Y" or a pump, then decide which way to go, I need to get it hooked up first though. I didn't see the fitting on the recirc pump, (top, side, bottom?)

Thanks for your response.

 

Don’t wait to install Y and or pump,  your under the dash , your all in the motor area, running the straight shot to the barb on Y as a first time measure snd hook up,  won’t have to try that very hard to loosen return cap plug( I had to cap a hose with NPT to block mine as I couldn’t get a wrench on it without stripping the hex head) . 
 

the Heater works pretty pitiful without either .  Choice is simple you want strong heat with motor off and at idle snd hotter while under way with motor go pump 

or Y gives no off motor heat but same exact improvement at idle snd so much hotter underway, you will be disappointed with the standard set up  .  Since your under the dash , the pump would be best 

I have the Y

if you have any trouble getting that return plug off without stripping , you can use a Y for return snd instsll pump

[justgary]

@granddaddy55 may be onto the reason that your heater was never hooked up.  Getting the plug out of the intake manifold is the first step, and it probably likes the thought of staying where it is.  IIRC, it's a 3/8" hex key, but you need enough height to get over the fuel rail and other stuff nearby.  I think I used one with a 1/2" square drive that I could put on the end of an extension and a breaker bar.

[iliketoski]

Since my Malibu is in my garage, I messed with it yesterday (Same engine as the Supra and the heater).  Using a hex socket with a good size breaker bar on it I was able to take the plug out of the intake manifold, it measures 3/4".  After how hard it was getting that plug out, I'm thinking the one on the recirc pump will be more difficult since it is a square head, making less than ideal to get some good torque on it.  Soooooo, all said it may just be easier to put the "Y" in and get the better performance.

[justgary]

I remember needing additional puissance to get that plug out.  It looks like you are well on your way to glory with this project.  I don't remember the square plug being that hard, but I do happen to own a decent 1/2" drive extension.  Put that on the plug and then you can get at the other end with your favorite large adjustable wrench.

It turns out that I found my spare Y fitting (I bought a heater kit but can't use it with closed cooling, so it is new) after the market high last winter when Heatercraft ran out of them.  Make me an offer via PM if you want mine, but I still think I'd go with the pump instead.

[Eagleboy99]

1 hour ago, justgary said:

puissance

Nice.    A great 50 cent word.  

[justgary]

pu·is·sance

/ˈpwisəns,ˈpyo͞oəsəns,pyo͞oˈisəns/

noun

1.

a competitive test of a horse's ability to jump large obstacles in show jumping.

"nine horses contested last night's Puissance"

2.

ARCHAIC•LITERARY

great power, influence, or prowess.

 

13 minutes ago, Eagleboy99 said:

Nice.    A great 50 cent word.  

You don't really get a chance to use it every day, but it seemed wholly appropriate for the discussion.  Getting that plug out is *not* easy.  Not sure why they tag the usage as archaic and literary, since it's clearly the word for the job....

[Eagleboy99]

Well, in French it is not archaic:  means "power" and still used.

[justgary]

2 hours ago, Eagleboy99 said:

Well, in French it is not archaic:  means "power" and still used.

C'est vrai!  Mais bien sûr!

[granddaddy55]

On 10/23/2019 at 7:06 AM, iliketoski said:

Since my Malibu is in my garage, I messed with it yesterday (Same engine as the Supra and the heater).  Using a hex socket with a good size breaker bar on it I was able to take the plug out of the intake manifold, it measures 3/4".  After how hard it was getting that plug out, I'm thinking the one on the recirc pump will be more difficult since it is a square head, making less than ideal to get some good torque on it.  Soooooo, all said it may just be easier to put the "Y" in and get the better performance.

BINGO, snd now you actually get a working heater , the Y makes idle almost hot and under way it’s hot under a garment or blanket 

[granddaddy55]

On 10/23/2019 at 9:34 AM, justgary said:

I remember needing additional puissance to get that plug out.  It looks like you are well on your way to glory with this project.  I don't remember the square plug being that hard, but I do happen to own a decent 1/2" drive extension.  Put that on the plug and then you can get at the other end with your favorite large adjustable wrench.

It turns out that I found my spare Y fitting (I bought a heater kit but can't use it with closed cooling, so it is new) after the market high last winter when Heatercraft ran out of them.  Make me an offer via PM if you want mine, but I still think I'd go with the pump instead.

You finally found it?  was it you who offered it up when mine was back ordered?

[granddaddy55]

On 10/23/2019 at 7:06 AM, iliketoski said:

Since my Malibu is in my garage, I messed with it yesterday (Same engine as the Supra and the heater).  Using a hex socket with a good size breaker bar on it I was able to take the plug out of the intake manifold, it measures 3/4".  After how hard it was getting that plug out, I'm thinking the one on the recirc pump will be more difficult since it is a square head, making less than ideal to get some good torque on it.  Soooooo, all said it may just be easier to put the "Y" in and get the better performance.

you could tell they sort of stripped the NPT hex head nipple the factory installed for my factory installation on the return to circ pump , so  it’s not an easy out 

When you cut the main intake line, loosen the clamp at Johnson pump housing and slide it down to your planned cut point , tighten it down and use it as a cutting edge guide

they recommend two cuts about 3/4 inch apart for room for barb to project out but I did one cut , have a snipper available to snip or trim reinforcement wire 

Edited October 25, 2019 by granddaddy55

[granddaddy55]

This is what I had to do to cap it

[justgary]

10 hours ago, granddaddy55 said:

You finally found it?  was it you who offered it up when mine was back ordered?

Yes.  I had hidden it from myself very well.  Now it's just back to the standard hidden.