Rewiring Heater pump to NOT run all the time? Been Done?

[DRHRSH]

2016 Craz, 1st heater pump leaked after 2 yrs, under warranty. 2nd Heater pump is leaking this summer, I just replaced it. My friends have had the same issue with a Supra and a Tige, after only 4 yrs. As you may know these pumps run the entire time the engine is running. The Heater switch simply turns on the fan. I have thought of re wiring the pump with one of my unused spare toggle switches to run when I turn it on, along with the fan. The “heater core” is a small mini radiator and I don’t know how much it contributes to engine cooling? I’m thinking the only reason they wire it this way is that there must be some additional benefit to engine cooling? I know I could test it by cutting the wires to the pump and seeing how the engine temp reacts. Has anyone done this or had any experience trying re wiring? Thank you.

[Holdmybeer]

Check your heater plumbing circuit.

The pump is running to keep hot closed loop coolant circulating. The heater core will not provide any cooling benefits to the engine but if not running the pump restricts coolant flow it was cause problems.

If the heater coolant lines circuit are independent of the other engine cooling, I would definitely go the route you are thinking. No reason to run something 100% for no reason.

[996scott]

I would be really interested in this as well. I have replaced my pump once already and a little uneasy waiting for it to happen again.

[KnoxMojo]

If you don't care about heat, just pull your hoses and run a barb fitting between the 2 and unplug your pump. That is what you do when you have a leak anyway. Wiring a local switch to behind the seat wouldn't be hard. Just run it inline with the pump for on off. Running to the dash would be harder of course. You can also buy the pump housing off amazon for under $100. Don't ask for the link use google search or amazon for sureflo and off brand replacements will come up there are aftermarket.

[HFarr]

We watched fireworks from my boat this past July 4th, and it was about 97 degrees with no wind that night. We were roasting while just floating among about 100 other boats. I turned on my heater without the engine running, and in less than 2 or 3 minutes, it was like having two fans blowing ambient air. It didn't take long for everyone to start fighting over who would hold the two ducts! Made me think that Skiers should have a damper option to blow cold or hot air in those heaters!

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[996scott]

I know almost nothing about electrical stuff but I would think that you could unplug the electrical connection from the circulating pump and then tap into the wiring that turns on the blower and connect that to the pump as well. That way when you turn on the heater the blower AND the pump will both turn on? Or am I way off base?

[Holdmybeer]

I would want them on 2 different switches.
Like Knox said, leave the fan switch on the dash but add a switch under the seat for just the pump. This way you have ambient air without the pump and heat with the pump.

However, make sure the pump coolant line are aux hose loops and not part of the main
trunk system. Otherwise, you are going to add restriction to the cooling loop by not spinning the heater pump and could overheat the engine.

[Holdmybeer]

We watched fireworks from my boat this past July 4th, and it was about 97 degrees with no wind that night. We were roasting while just floating among about 100 other boats. I turned on my heater without the engine running, and in less than 2 or 3 minutes, it was like having two fans blowing ambient air. It didn't take long for everyone to start fighting over who would hold the two ducts! Made me think that Skiers should have a damper option to blow cold or hot air in those heaters!

Sent from my SM-G781V using Tapatalk

Next time just stack ice on the heater core to cool the aluminum. Wouldn't have been the most efficient but 5 degrees cooler would have felt like A/C.

[DRHRSH]

Thanks for the replies. The way I see it the heater circuit is not part of engine cooling. I guess the way to check it is to stop the pump from running ( cut a wire?) and watch the engine temp. If it stays the same then my idea would work. Why do some of you suggest “under seat switch”?

[Holdmybeer]

The heater is under the seat. If you cut a wire under the seat then add a switch.
Switch under the seat - get it.... lol

The biggest reason is it is simple to do. The heater is now only on when you want, and you can run the fan without heat as HFarr mentioned. Or flip the switch under the seat and you have heat on colder days.