Adding a Coolant Level Sensor!!

Post by **kcodyjr** » 21 Sep 2016, 11:16

Depends on how the temperature sensor acts normally. Is overtemp represented by a high resistance or a low resistance?

If overtemp is a high resistance (trending toward an open circuit) then I'd wire the coolant level sensor with it in series, and use a coolant sensor that opens the circuit when the level drops too low.

If overtemp is a low resistance (trending toward a short circuit) then I'd wire the coolant level sensor with it in parallel, and use a coolant sensor that closes the circuit when the level drops too low.

That way, the computer will read a loss-of-coolant event as an immediate overheat.

Post by **oragex** » 21 Sep 2016, 15:35

I'd google see if reservoirs with sensor from other vehicles are small enough to fit the S40, even from other brands, Mazda, Toyota, might be lucky

Post by **kcodyjr** » 21 Sep 2016, 17:47

You know, another option is to wire an open-on-low-coolant sensor in series with the fuel pump relay (control side).

Immobilizing the vehicle if it loses coolant isn't an entirely insane thing to do.

Post by **MadeInJapan** » 22 Sep 2016, 21:11

Great ideas!! The sensor I got can either be set to open or close depending on if I turn the float around or not. I looked but there is not much room in our reservoir tanks for much in regards to third party (other maker's float sensors)...the small tank is separated into 6 chambers with walls in the sides. Straight up and down near the filler cap seems the only logical placement. Keep posting everyone!!

Post by **abscate** » 29 Sep 2016, 00:24

Well..if you want us to follow at least show pictures of the boat...

How about tying it into a bulb or interior light to give a visual cue?

It is amazing this series uses overheat as the low coolant warning...ouch!

Radio Shavk would have a buzzer that would work here

Post by **MadeInJapan** » 29 Sep 2016, 20:51

Yes, I have considered a buzzer...I'm leaning towards that.
I'd use a light except it was a real bitch to get a thin, smooth boost lines into the cabin for my boost gauge...I can't imagine fishing wires through the thick rubber piece that I had to poke through- it seals up like the rubber port of a medicine bottle as soon as you pull out whatever it is you poke into it.

Boat pictures? Hmmm- let me get the boat in the water (hopefully this weekend) and I'll snap a shot!

beigg · Post by **beigg** » 16 Jan 2017, 14:55

Has this project come to fruition? If not, the ones below might flow some more ideas to enable a rather cool project and needed operator awareness.

http://www.ebay.com/itm/Engine-Coolant- ... 1596899455

http://www.ebay.com/itm/BMW-Coolant-Rec ... 0991161589

http://www.ebay.com/itm/2012-2017-SONIC ... 2469557131

http://cdn4.pelicanparts.com/techarticl ... /pic01.jpg

http://ep.yimg.com/ay/yhst-142118241567 ... 9-z3-3.gif

http://www.bavauto.com/lview.asp?imgfil ... 529273.jpg

Post by **MadeInJapan** » 21 Jan 2017, 01:01

beigg, thanks for your posted links. I really cannot use a different tank as there is no room for much of a tank to begin with. I think I've figured things out but I've gotten lazy and so have not worked on this since last year. When it warms up, I'll cut the actual hole in the bottom of the tank already in the care and give it a go. I just don't want any leaks or else this will be self-defeating!!! But...it looks like the only place I can get a float sensor to sit is from an opening in the bottom of the tank (like my pictures show from page 1 of this thread).

Post by **Krons** » 17 Jan 2023, 13:25

MadeInJapan curious if you ever went though with this sensor? As I’m digging into my newly acquired C70 thinking about how to alert low coolant. Step one for me will be replacing the octopus hose.

Richard99 · Post by **Richard99** » 17 Jan 2023, 23:26

There is a video by Robert DIY on how to do this

Adding a Coolant Level Sensor!!

Re: Adding a Coolant Level Sensor!!