Electric Water Pumps (EWP)

madjak · Postby **madjak** » Tue Aug 30, 2016 2:41 pm

The control level for me isn't that sophisticated, but I'll have a play with the PWM setup in the ECU and see how I go... it would be nice to get some more advanced control rather than just on or off. Unfortunately I don't have much experience with the ECU mapping stuff so it might be a bit of a challenge.

I might grab a spare coolant sensor and my portable cooktop and set up a test bench in my workshop. eg Heat up the sensor to see if I can get the EWP to change speed.

Rick

Postby **NitroDann** » Tue Aug 30, 2016 2:48 pm

The SSR will turn on flat out with the key off.

The SSR will need 95% to get the pump to turn and at 96% will be flat out etc.

Im happy to advise when you come across these troubles.

Dann

Magpie · Postby **Magpie** » Tue Aug 30, 2016 3:21 pm

http://www.haltech.com/wp-content/uploads/2011/01/Solid-State-Relay-HT030202.pdf

As per Dann's advice you need to ensure the correct wiring of the SSR.

madjak · Postby **madjak** » Tue Aug 30, 2016 3:30 pm

My plan was to feed the SSR 12v via a second relay triggered by the ignition / control switch so that when the key is off and the ECU stops controlling the PWM line the EWP doesn't power on.

I don't think it's that tricky. I'll have a play in the following week and see where I get to. Basically that Haltech wiring is correct, but with a second relay under the "to switched 12v supply"

bruce · Postby **bruce** » Tue Aug 30, 2016 3:30 pm

Thanks for that info re exhaust wrap.

3gress · Postby **3gress** » Wed Aug 31, 2016 3:26 am

Madjak the instructions provided with the pump suggest to have the weephole tube pointing as close to 6 o'clock as possible or alternately sealing the tube with sealant. You can reclock the two halves of the pump by removing the bolts and carefully rotating one half to get the weephole pointing downwards. They do suggest being careful not to seperate the two halves too much whilst doing so. Hope this helps mate.

Postby **NitroDann** » Wed Aug 31, 2016 9:23 am

madjak wrote:My plan was to feed the SSR 12v via a second relay triggered by the ignition / control switch so that when the key is off and the ECU stops controlling the PWM line the EWP doesn't power on.

I don't think it's that tricky. I'll have a play in the following week and see where I get to. Basically that Haltech wiring is correct, but with a second relay under the "to switched 12v supply"

This is what I did, but there are overall some issues regardless, youll work it out youre a clever dude.

Dann

sailaholic · Postby **sailaholic** » Wed Aug 31, 2016 10:05 am

If you are going for a second sensor I would probably make it a cylinder head temp, ie a thermocouple bolted to the head. That way if you have a coolant loss the sensor still reads accurately.

Alternatively a pressure sensor in the coolant flow is something Emilio uses.

Magpie also uses a coolant level sensor. Really comon in commercial / mine vehicles. Generally just activates a loud buzzer.

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madjak · Postby **madjak** » Wed Aug 31, 2016 4:53 pm

I like the idea of the thermocouple as it's actually reading the head temp which will tell you if you have lost coolant or the pump has stopped running. The issue with the pressure sensor is you can actually have increased pressure when the pump stops as the coolant boils in the head. The coolant flow would be fine too.

edit: It looks like you can buy type-K thermocouples with a washer sensor which will be ideal.

edit2: Bought one...

Postby **NitroDann** » Wed Aug 31, 2016 6:20 pm

The pressure sensor tells you if you have a leak, not if the pump failed.

Dann

3gress · Postby **3gress** » Wed Aug 31, 2016 7:24 pm

What about a low coolant level senser such as those offered by cartek? It fits inline with the top hose and triggers a buzzer and/or dash indicator light to warn of impending doom. It would give an early indication of a coolant leak, not so much a failed pump though. What brand coolant flow sensors have any of you chaps used?

Magpie · Postby **Magpie** » Thu Sep 01, 2016 5:08 am

I use the Cartek one.

madjak · Postby **madjak** » Fri Sep 09, 2016 2:07 am

Tonight I wired up the EWP and the SSR and powered it via what I think is the remains of the heater 12V source. Anyway I get 12v on when I turn on the key which is handy. Later I'll wire it up through my central breakers on my control panel.

The SSR is wired as per the Haltech guidelines and I added the output to the ECU and enabled the table. The EWP powered on no problems and changing the PWM from 0% through to 100% changes the speed of the pump linearly well it sounds it by the pitch of the motor. What I thought would be hard ended up being a 5 minute wiring job! I've read if you get the wrong SSR it can be hard to configure.

Anyway I set the table up on my Haltech so that CTS is mapped vs manifold pressure. So on 0 pressure and anything below 30 degrees the output is set to 0%. This means with the ignition on, the pump doesn't run if the engine is cold. At all other CTS under 90 degrees I've set the PWM to be 30% and then over the next 10 degrees through to 100 degrees the PWM steps up to 100%.

I'll tweak the map when I run the engine but so far it's all been fairly straight forward. I'll report back when I've actually run the car.