electric WP relay failures

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Apr 2, 2009 | 08:10 AM

kwd1

Thread Starter

Melting Slicks

Joined: Apr 2002

Posts: 2,947

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From: North Aurora Il

electric WP relay failures

Hi all,
I've been running an electric WP for about the last 4 years/2000 miles. In that time I've had 4 relays go bad on me. I was using autozone high current relays. Switched to the relay from Ecklers:
http://www.ecklers.com/product.asp?p...6&dept_id=1126

The relay is labeled as rated to 40 amps. This last one went bad after 1 year/200 miles.

Any ideas why a relay would continually fail like this? Could the pump be drawing too much current? The last time it failed, the pump was not running and the relay was warm.
thanks
Ken
PS man I need to drive this car more....

Apr 2, 2009 | 08:56 AM

dizwiz24

Race Director

Joined: Sep 2001

Posts: 14,674

Likes: 751

From: NEwhere Ohio

This is exactly why I never did the electric water pump mod.

Despite a proven power gain, I never ' trusted' it in terms of reliability.

Someone had posted about a relay failure (no problems with the pump, just the relay) and ended up overheating. They warped their heads.

I think Nathan Plemons hooked his up in a such a way that his dash lights would go out if the relay failed.

I cant answer why the relay failed.

I can conly tell you that back 8 years ago, when I was considering it, people were using 'Barry Grant Relays'

or something like that.

Im not 100% sure of the name, but the company name was someones name.

Apr 2, 2009 | 09:17 AM

kwd1

Thread Starter

Melting Slicks

Joined: Apr 2002

Posts: 2,947

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From: North Aurora Il

I may have figured it out. I cracked open the old relay and found the inside was rusted and corroded! Reason for this was I had mounted the relay with the terminals pointing up! I did this just because thats the way it fit best. But if you notice, all the stock relays are mounted with the terminals down!! Makes sense, water must have gotten on the terminal block and seeped through.

I'm in a WP thread a few years ago where someone had posted a wiring diagram for a buzzer if the WP was not running.

Apr 2, 2009 | 10:50 AM

anesthes

Safety Car

Joined: May 2006

Posts: 4,290

Likes: 140

From: Salem NH

Never really understood electric waterpump.

Alt is belt driven. So while saving the load of the waterpump your adding to the load on the alt.

-- Joe

Apr 2, 2009 | 01:35 PM

bjankuski

Safety Car

Joined: Sep 2001

Posts: 4,157

Likes: 554

From: Glenbeulah Wi

Quote:

Originally Posted by anesthes

Never really understood electric waterpump.

Alt is belt driven. So while saving the load of the waterpump your adding to the load on the alt.

-- Joe

That is true but at high RPM the mechanical water pump puts alot more load on the engine then the electric water pump. That is where you save your power.

Apr 2, 2009 | 01:41 PM

tachout

Racer

Joined: Jun 2007

Posts: 486

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From: Sandy Ut

In the build I am doing I am going to be doing an electric water pump drive. I am going to replace the motor with something with just a little more umpf, and want to run the water pump and alt as well. My only thought in doing so is I could run the electic water pump after running it hard, and help cool the engine, while still charging the battery. I am wanting to also put an electric oil pump in. This will not be for engine oiling, but instead for the oiling for the twin turbos to help them cool down after running hard. Not sure if it will work, but still looking into it. Got to keep the relays in mind, and am going to put in a trouble light, as well as, a buzzer so I know if something goes wrong. Thanks for the added ideas to this circuit.