Electric vs Mechanical Water Pump
TECH Veteran
Joined: Apr 2008
Posts: 4,985
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these are the install instructions that come with pump. Electrical is brief. You want a relay that is triggered with key on (IGN) and a good, fused power source like the AUX post on fuse block if your car has that
WP118 INSTALL REV A-65.indd (meziere.com)
I suspect there are specific 4th gen relay install videos...but some are scary wrong
YOU DO NOT NEED TO TAP AND THREAD THE WEEP HOLE. THE FREEZE PLUG BLOCKS THAT PASSAGE. you do not need to remove the WP drive spline from timing cover
Wiring for Vette, similar idea for Camaro
WP118 INSTALL REV A-65.indd (meziere.com)
I suspect there are specific 4th gen relay install videos...but some are scary wrong
YOU DO NOT NEED TO TAP AND THREAD THE WEEP HOLE. THE FREEZE PLUG BLOCKS THAT PASSAGE. you do not need to remove the WP drive spline from timing cover
Wiring for Vette, similar idea for Camaro
Thread Starter
Teching In
Joined: Nov 2021
Posts: 13
Likes: 1
these are the install instructions that come with pump. Electrical is brief. You want a relay that is triggered with key on (IGN) and a good, fused power source like the AUX post on fuse block if your car has that
WP118 INSTALL REV A-65.indd (meziere.com)
I suspect there are specific 4th gen relay install videos...but some are scary wrong
https://youtu.be/xUnnKblUj2Q
YOU DO NOT NEED TO TAP AND THREAD THE WEEP HOLE. THE FREEZE PLUG BLOCKS THAT PASSAGE. you do not need to remove the WP drive spline from timing cover
Wiring for Vette, similar idea for Camaro
https://youtu.be/DOeCkHOslHg
WP118 INSTALL REV A-65.indd (meziere.com)
I suspect there are specific 4th gen relay install videos...but some are scary wrong
https://youtu.be/xUnnKblUj2Q
YOU DO NOT NEED TO TAP AND THREAD THE WEEP HOLE. THE FREEZE PLUG BLOCKS THAT PASSAGE. you do not need to remove the WP drive spline from timing cover
Wiring for Vette, similar idea for Camaro
https://youtu.be/DOeCkHOslHg
Thread Starter
Teching In
Joined: Nov 2021
Posts: 13
Likes: 1
On The Tree
Joined: Mar 2006
Posts: 122
Likes: 10
Some other things to consider
You can also wire the EWP relay to trigger off the fuel pump relay so it only runs when the fuel pump is running. That way if you ever need to have your ignition on for an extended time with the engine not running, the EWP isn't running the whole time. Good for when you're working on the car or when you're reprogramming, etc.. Otherwise be careful if you ever disconnect the pump wiring or pull the EWP fuse (if you have one) to keep it (EWP) off, cause you might forget to put the fuse back, then it might overheat, and that happens fast if you're driving it. And its easy enough to put additional switches to turn the EWP on and the fans on if you want to cool the engine down while it isn't running like when you're in between runs at the track or bleeding the coolant system.
You can also wire the EWP relay to trigger off the fuel pump relay so it only runs when the fuel pump is running. That way if you ever need to have your ignition on for an extended time with the engine not running, the EWP isn't running the whole time. Good for when you're working on the car or when you're reprogramming, etc.. Otherwise be careful if you ever disconnect the pump wiring or pull the EWP fuse (if you have one) to keep it (EWP) off, cause you might forget to put the fuse back, then it might overheat, and that happens fast if you're driving it. And its easy enough to put additional switches to turn the EWP on and the fans on if you want to cool the engine down while it isn't running like when you're in between runs at the track or bleeding the coolant system.
Last edited by Kevin Blown 95 TA; Jan 13, 2023 at 08:01 PM.
Thread Starter
Teching In
Joined: Nov 2021
Posts: 13
Likes: 1
Some other things to consider
You can also wire the EWP relay to trigger off the fuel pump relay so it only runs when the fuel pump is running. That way if you ever need to have your ignition on for an extended time with the engine not running, the EWP isn't running the whole time. Good for when you're working on the car or when you're reprogramming, etc.. Otherwise be careful if you ever disconnect the pump wiring or pull the EWP fuse (if you have one) to keep it (EWP) off, cause you might forget to put the fuse back, then it might overheat, and that happens fast if you're driving it. And its easy enough to put additional switches to turn the EWP on and the fans on if you want to cool the engine down while it isn't running like when you're in between runs at the track or bleeding the coolant system.
You can also wire the EWP relay to trigger off the fuel pump relay so it only runs when the fuel pump is running. That way if you ever need to have your ignition on for an extended time with the engine not running, the EWP isn't running the whole time. Good for when you're working on the car or when you're reprogramming, etc.. Otherwise be careful if you ever disconnect the pump wiring or pull the EWP fuse (if you have one) to keep it (EWP) off, cause you might forget to put the fuse back, then it might overheat, and that happens fast if you're driving it. And its easy enough to put additional switches to turn the EWP on and the fans on if you want to cool the engine down while it isn't running like when you're in between runs at the track or bleeding the coolant system.
Some other things to consider
You can also wire the EWP relay to trigger off the fuel pump relay so it only runs when the fuel pump is running. That way if you ever need to have your ignition on for an extended time with the engine not running, the EWP isn't running the whole time. Good for when you're working on the car or when you're reprogramming, etc.. Otherwise be careful if you ever disconnect the pump wiring or pull the EWP fuse (if you have one) to keep it (EWP) off, cause you might forget to put the fuse back, then it might overheat, and that happens fast if you're driving it. And its easy enough to put additional switches to turn the EWP on and the fans on if you want to cool the engine down while it isn't running like when you're in between runs at the track or bleeding the coolant system.
You can also wire the EWP relay to trigger off the fuel pump relay so it only runs when the fuel pump is running. That way if you ever need to have your ignition on for an extended time with the engine not running, the EWP isn't running the whole time. Good for when you're working on the car or when you're reprogramming, etc.. Otherwise be careful if you ever disconnect the pump wiring or pull the EWP fuse (if you have one) to keep it (EWP) off, cause you might forget to put the fuse back, then it might overheat, and that happens fast if you're driving it. And its easy enough to put additional switches to turn the EWP on and the fans on if you want to cool the engine down while it isn't running like when you're in between runs at the track or bleeding the coolant system.
Thread Starter
Teching In
Joined: Nov 2021
Posts: 13
Likes: 1
I got everything buttoned up and running. Just have to get more coolant and bleed the air but the fan was running strong. I wish I could have hid the wires a bit more but I'm not complaining! Had to trim the fan shroud a decent amount but its not noticable unless I tell someone is did. I appreciate everyone who helped me with this process! Hopefully I don't have to worry about my water pump failing for a while. If I remember I will reply with how the first cruise goes! Thanks again!
OP
I have never had overheating issues with my EWP in 22 years. 118 degrees Vegas with AC on, no issues
You need to gut the stock WP housing and install the Meziere on it. Instructions come with EWP. You do need to wire up a relay for the EWP
You can just leave the WP drive gear installed in motor. The spline collar for the mechanical WP will not be used
I have never had overheating issues with my EWP in 22 years. 118 degrees Vegas with AC on, no issues
You need to gut the stock WP housing and install the Meziere on it. Instructions come with EWP. You do need to wire up a relay for the EWP
You can just leave the WP drive gear installed in motor. The spline collar for the mechanical WP will not be used
TECH Fanatic
Joined: Jul 2007
Posts: 1,800
Likes: 326
From: Wilmington, De
Since I am using a Terminator X, I am using an output that is setup to ground the relay when the coolant temp is at least 80 degrees and the engine RPM is at least 500. That way, the pump isn't drawing current during cranking and isn't running with just the ignition. I can also open up the program and command it on whenever I want.
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
All great replies and I agree as well. Had one on my Impala for many years. The only issue I had was it would sometimes blow the inline fuse. So I replaced the fuse with a 2 blade breaker. The best part about a EWP is that, unlike a mechanical pump that varies with rpm, it flows the same no matter what. Which it make bleeding the cooling system on an LT1 simple. You don't even have to start the car.
All great replies and I agree as well. Had one on my Impala for many years. The only issue I had was it would sometimes blow the inline fuse. So I replaced the fuse with a 2 blade breaker. The best part about a EWP is that, unlike a mechanical pump that varies with rpm, it flows the same no matter what. Which it make bleeding the cooling system on an LT1 simple. You don't even have to start the car.