How to turn your heater core off and on in the cab.

[Waterloo]

(05-19-2019 )earnies2 Wrote:  Thanks I will get that done do you have a wiring diagram?

It was easy, the wiring diagram came with the valve to use with the DPDM switch I posted. I went and looked to see if I still have it, but I think I tossed it... I'll draw one up from memory, it was easy. I'll post below.

You attach the valve, the two wires off of the valve, a blue and red. Red is power blue is ground, they were 18ga, kind of thin but they were tinned at the ends. I had some 16ga wire that I used to run into the cab. I used these butt connectors with shrink tube under the hood... https://amzn.to/2WecARm
The reason I use these particular butt connectors is that the fit nicely in the split loom, no bulging out of the loom, like there is no butt connector under there. I bought the crimper that is used for these, you could probably improvise, but I like tools. LOL... Here is the crimper... https://amzn.to/2HrI12z

I ran the wires through the firewall directly to the switch. There are six contacts on the On/Off/On switch, you need to make 2 jumpers, I used the 16 ga wire, about three or four inches long, one shorter than the other as they cross each other. I used the blue crimp on eyelets, the smallest ones they sell at O'Riely Auto Parts. You will need 6 of those. I used shrink tube on all connections.

I cheated and used those quick connect wire taps to hook to ground and power in the dash. This is a very low voltage valve, only 9 volts required to operate, I did not use an inline fuse. I did not think it was necessary.

I used a 1/2" drill to make the hole in the dash to hold the switch in place.

Here are the wiring schematics.


  Scan May 19, 2019 at 08.40.pdf (Size: 349.65 KB / Downloads: 267)

Side note, attach the valve before you wire unless you are using barb connectors. I had to screw the valve on to a pipe nipple, so prewiring would have not worked for me.

[Rawze]

(05-19-2019 )Waterloo Wrote:  ...
I did not use an inline fuse. I did not think it was necessary.

...

ALWAYS ALWAYS ALWAYS USE A FUSE when wiring something to the batteries of the truck. -- and if your not sure what size, then use the correct size fuse for the gauge wire you used. You should also install the fuse in line close to the power feed point end of your circuit as well (nearest to the batteries or other point you got power from).

All it takes is a split second for a wire to short out and it will melt the insulation off itself and every wire or system it is in contact with,.. then a chain reaction starts and the whole truck goes up in flames.

[Waterloo]

I will put one in... Thanks Rawze. I gutted out the dash, so everything is easily accessible... I now understand why you did that. I'll post some photos of my new cup and junk tray holder... 1/2" pipe nipple, and it all swings out of the way...

[Rawze]

(05-19-2019 )Waterloo Wrote:  I will put one in... Thanks Rawze. I gutted out the dash, so everything is easily accessible... I now understand why you did that. I'll post some photos of my new cup and junk tray holder... 1/2" pipe nipple, and it all swings out of the way...

LOLZ!- I knew you would eventually see the light on that one. I hate all the excessive plastic garbage wasted spaces in the dash and leg areas of the prostar. Its a truck dammit!,.. stripp all that space-consuming, leg cramping junk off, tidy up the stuff underneath and behind them that they were covering up, and never look back. - SAME THING WITH THE BACK WALL OF THE SLEEPER. lol

In fact, someone came over here once with a prostar that they had completely gutted all the plastic and trim out of the truck 100% because they were getting ready to make custom interrior. -- It was significantly more roomy inside that truck as a whole and I think in the end he simply installed a thin automotive carpet onto the bare framework and it looked pretty darn good.

[Waterloo]

(05-19-2019 )Rawze Wrote:  

(05-19-2019 )Waterloo Wrote:  I will put one in... Thanks Rawze. I gutted out the dash, so everything is easily accessible... I now understand why you did that. I'll post some photos of my new cup and junk tray holder... 1/2" pipe nipple, and it all swings out of the way...

LOLZ!- I knew you would eventually see the light on that one. I hate all the excessive plastic garbage wasted spaces in the dash and leg areas of the prostar. Its a truck dammit!,.. stripp all that space-consuming, leg cramping junk off, tidy up the stuff underneath and behind them that they were covering up, and never look back. - SAME THING WITH THE BACK WALL OF THE SLEEPER. lol

In fact, someone came over here once with a prostar that they had completely gutted all the plastic and trim out of the truck 100% because they were getting ready to make custom interrior. -- It was significantly more roomy inside that truck as a whole and I think in the end he simply installed a thin automotive carpet onto the bare framework and it looked pretty darn good.

Oh yeah... Been eyeballing the sleeper too... LOL!

[earnies2]

Thanks I have ordered the parts and will install when I get home I might need to do some rerouting on the hoses because of the APU but I will figure that out. Thanks for the wireing diagram and I will definitely put a fuse inline...

[Waterloo]

(05-24-2019 )earnies2 Wrote:  Thanks I have ordered the parts and will install when I get home I might need to do some rerouting on the hoses because of the APU but I will figure that out. Thanks for the wireing diagram and I will definitely put a fuse inline...

Just find the hose to the heater core going into the firewall, inlet side, install the valve between there (firewall) and the APU valve or T. The valve is the same size as a 1/2" NPT ball valve you will find at Home Depot, about 2.5" to 3" long. I am thinking you will probably need some hose barbs, 1/2" NPT to whatever the ID of your heater hose is, normally around 5/8" on the hose barb. you can find them in straight, 45* and 90*, Amazon, of course has the best selection. Cummins will normally carry them at a premium, and FleetPride too, if you have one near you.

Some examples...

https://amzn.to/2W2WMBN

https://amzn.to/2Wm0Koy
Here are some fantastic hose clamps, I like to use these particular ones as they compress without tearing up the hose. Worth the money in my book. Good quality.

https://amzn.to/2HzlsZz

[earnies2]

(05-24-2019 )Waterloo Wrote:  

(05-24-2019 )earnies2 Wrote:  Thanks I have ordered the parts and will install when I get home I might need to do some rerouting on the hoses because of the APU but I will figure that out. Thanks for the wireing diagram and I will definitely put a fuse inline...

Just find the hose to the heater core going into the firewall, inlet side, install the valve between there (firewall) and the APU valve or T. The valve is the same size as a 1/2" NPT ball valve you will find at Home Depot, about 2.5" to 3" long. I am thinking you will probably need some hose barbs, 1/2" NPT to whatever the ID of your heater hose is, normally around 5/8" on the hose barb. you can find them in straight, 45* and 90*, Amazon, of course has the best selection. Cummins will normally carry them at a premium, and FleetPride too, if you have one near you.

Some examples...

https://amzn.to/2W2WMBN

https://amzn.to/2Wm0Koy
Here are some fantastic hose clamps, I like to use these particular ones as they compress without tearing up the hose. Worth the money in my book. Good quality.

https://amzn.to/2HzlsZz

Thanks again I put all the stuff in my cart.....its on the bucket list

[Waterloo]

I finally got to drive the truck, and this new ball valve is working like a champ! I had heat in the morning and ice cold AC that afternoon. Flip dash switch up and hold for 3 seconds, return to off position, AC starts blowing. Want heat, flip switch down for 3 seconds and then return to off position, heat starts working. Only used it a couple of times, but the darn thing works. And I did add an in line fuse, 2 amp.