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Discussion Starter · #1 ·
i need a bit of help with the electric water pump on my 06 elise.i just installed a new engine and it took some doing but i got the cooling system bleed.its cerculating water.problem that im having is that the fans dont come on.and the electric pump is not running.it got as high as 202f.i would like to know how the fans and pump are wired?what temp sensor turns them on?i also read somewhere that the electric pump only runs after the motor is turned off.any help here would be great.

kevin
 

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99% sure the main coolant is driven by the engine mechanical pump. The electric pump is only as you say to circulate it after engine off. Very few road cars rely on a electric water pump during engine operation.

If the fans are not coming on then worth checking fuses and relays for starters.
Then see if power is getting to the fan itself - it's not unknown for fans to fail.

The engine coolant sensor is mounted on the engine block - it's between the primary water engine outlet (massive hose can't miss it) and the heater matrix outlet. As you look at the engine from the back of the car it's on the left hand side in the middle.

This also feeds the CAN bus for the dash display so if it's reading it looks ok. IIRC if the ECU doesn't get a water temp feed it'll throttle back into a massive limp home setting and run the fans constantly (to be on the safe side)
 

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Discussion Starter · #3 ·
thanks for the reply.i just read on another post that the fans come on around 209.so i guess i didt get it hot enough for them to turn on.does anyone know when the electric pump does come one?is it key off and water temp higher than 209?i dont know if i have a problem with it or not.
 

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Discussion Starter · #5 ·
yea i was just running the car and i turned the ac on and i had fans running.i guess they run at half speed for the ac?i didnt check to see if the pump started running.anyone ever determine when the electric pump runs?i would guess you could hear it when you turn the car off?
 

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If you are talking about the small electric pump under the coolant bottle, it is a heat soak pump, not a cooling pump and not intended for the primary cooling needs. The main water pump is belt driven off of the main accessory drive
 

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Discussion Starter · #7 ·
If you are talking about the small electric pump under the coolant bottle, it is a heat soak pump, not a cooling pump and not intended for the primary cooling needs. The main water pump is belt driven off of the main accessory drive
yea i found this out.im just trying to figure out when it runs to see if mine is working.i would like to know when it comes on?at what temp?key on?key off and what water temp so i can check to see if its working?i dont have a manual adont have the cash to buy one or the time to download it from lotus.i guess im going to have to make time.
 

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yea i found this out.im just trying to figure out when it runs to see if mine is working.i would like to know when it comes on?at what temp?key on?key off and what water temp so i can check to see if its working?i dont have a manual adont have the cash to buy one or the time to download it from lotus.i guess im going to have to make time.
It has to get pretty hot before anything happens.

From the Factory Service Manual (you have paid the $25 and downloaded it from LCU haven't you?):

The pump functions only with ignition off in conditions where the ECU remains live. The pump is then activated at coolant temperatures over 110°C, switching off at 100°C on fall. If temperature should rise to 115°C, the pump will be supplemented by the two cooling fans running at half speed, switching off at 110°C on fall.

I leave it to you to do the degrees Centigrade to Fahrenheit conversion (but 110°C is quite a bit above the 212°F boiling point)...
 

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Discussion Starter · #9 ·
thanks time for the info,no i have not downloaded the manual.that was the lack of time part of my prior post.i heard to set aside a weekend to get it done.thats from the thread on downloading it.i was reading some recent posts on there that said it was done in 15 minutes.so i guess i will find out.i also jumped the pump with 12 volts and it runs.its just the means of when the car turns it on.for now im going to assume that its working.
 
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