Electric waterpump wiring help needed!
Thread Starter
Melting Slicks
Joined: Jan 2002
Posts: 3,293
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From: Jackson MI
Electric waterpump wiring help needed!
Ok, I've got my water pump wired up to the cooling fan relay like I was instructed by some other forum members, but now I've got some weird problem. Every once in a while the water pump cuts out and my temp goes way up. If I shut the engine off and put the key to the "on" possition the pump goes back on, but when I start the engine up again it stops. It'll run normally after I let the car sit for a while until it happens again.
This case happens about 15-45 minutes after the car is up and running and the only other thing that I've noticed is that the light on my auto climate control flashes at me about 5-10 minutes before the water pump cuts out.
My temp fix for this is to pull the power leads from the relay and run them through a manual switch. Then it'll work perfect. I tried replaceing the relay, but the same thing happens. Any help in fixing this would be greatly appreciated!
This case happens about 15-45 minutes after the car is up and running and the only other thing that I've noticed is that the light on my auto climate control flashes at me about 5-10 minutes before the water pump cuts out.
My temp fix for this is to pull the power leads from the relay and run them through a manual switch. Then it'll work perfect. I tried replaceing the relay, but the same thing happens. Any help in fixing this would be greatly appreciated!
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Joined: May 2001
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Re: Electric waterpump wiring help needed! (mn_vette)
I can see 2 possible problems. Either your relay is flaky, or the wire you tapped to operate it isn't quite right.
It could be that the wire you tapped isn't hot all the time the key is on, and thus when that wire goes dead it drops out the relay. You might need to hunt around for another wire that is hot off the key. One of the wires going to the coil is always hot and will work. I used that on the last Meziere I wired up because it was on a Camaro and it was the first hot wire I found.
It could be that the wire you tapped isn't hot all the time the key is on, and thus when that wire goes dead it drops out the relay. You might need to hunt around for another wire that is hot off the key. One of the wires going to the coil is always hot and will work. I used that on the last Meziere I wired up because it was on a Camaro and it was the first hot wire I found.
Thread Starter
Melting Slicks
Joined: Jan 2002
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From: Jackson MI
Re: Electric waterpump wiring help needed! (John Row)
What color wire did you use on the fan relays?
Does the pump stay running when the fans are operating? and off when the fans are off?
Does the pump stay running when the fans are operating? and off when the fans are off?
I'm not sure if it's running when the fans are going and the engine is on. What would causes the fans to go on? If the engine is off and the key is in the on possition the pump will always go on. I believe the fans are on then too though, please correct me if I'm wrong, I very well could be.
Melting Slicks
Joined: May 2001
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From: San Diego CA
Re: Electric waterpump wiring help needed! (mn_vette)
Without the AC the fans come on around 228 degrees. With AC mine seem to cycle with the compressor (I really haven't paid that much attention to them).
The pink wire is correct. It should be hot when the ignition is ON. You might want to pull the relay and put a probe in that hole and see what the voltage is.
Also, where did you ground the wires? I used the ground on the frame just to the left front of the engine for both the relay and the pump. A good ground is critical.
I also heard that the inline fuse was not particularly robust so I cut it out and put a fuse holder in the battery compartment.
What kind of relay did you use?
[Modified by John Row, 12:01 PM 5/13/2002]
The pink wire is correct. It should be hot when the ignition is ON. You might want to pull the relay and put a probe in that hole and see what the voltage is.
Also, where did you ground the wires? I used the ground on the frame just to the left front of the engine for both the relay and the pump. A good ground is critical.
I also heard that the inline fuse was not particularly robust so I cut it out and put a fuse holder in the battery compartment.
What kind of relay did you use?
[Modified by John Row, 12:01 PM 5/13/2002]
Drifting
Joined: Nov 1999
Posts: 1,801
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From: St. Paul MN
Re: Electric waterpump wiring help needed! (John Row)
Maybe the '93 is different buy I'm pretty sure my car will not run the cooling fan with the engine off, key on. The ecm controls the fan and if the engine is off the fan will not come on, even if it is very hot. So, if the '93 is the same way I find it odd that when you turn on the key w/o starting it the water pump comes on. But maybe I'm missing something here.
Race Director
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Re: Electric waterpump wiring help needed! (Bob86ZZ4)
My fans don't come on either with the key on, car not running, but that doesn't change the fact that there is voltage to one side of the fan relay at all times when the key is in the ON position. That's what you are looking for, the input side of the fan relay, not the output side.
Thread Starter
Melting Slicks
Joined: Jan 2002
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From: Jackson MI
Re: Electric waterpump wiring help needed! (John Row)
I checked it with a voltmeter and the pink wire does seem to be getting grounded out when the fans turn on. Does anybody know of another wire that I could tap off of to get my relay to work?
Oh yeah, the fans are off when the engine isn't running
[Modified by mn_vette, 6:39 PM 5/13/2002]
Oh yeah, the fans are off when the engine isn't running
[Modified by mn_vette, 6:39 PM 5/13/2002]
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Race Director
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Re: Electric waterpump wiring help needed! (mn_vette)
Like I said you can pull one off the coil. I really didn't like going there, but it does work. The coil is mounted to the metal base with the ignition control module on it. The plug for the ICM has several wires that are hot with the key.
Like I said, I don't like going there, but it will work, just check it with the voltmeter before you do anything.
Like I said, I don't like going there, but it will work, just check it with the voltmeter before you do anything.
Melting Slicks
Joined: May 2001
Posts: 2,143
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From: San Diego CA
Re: Electric waterpump wiring help needed! (Bob86ZZ4)
Yep, pump comes on with ignition switch. Fans don't. I never bothered to see where the fan wires went. But now you peaked my curiosity. I'll have to dig into the manuals tonight.
There is a second relay, but I always assumed it was for the second fan.
There is a second relay, but I always assumed it was for the second fan.
Thread Starter
Melting Slicks
Joined: Jan 2002
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From: Jackson MI
Re: Electric waterpump wiring help needed! (Nathan Plemons)
Wait a minute......Here's a question, the ground to the other side of the relay for the water pump is hooked up to the black wire (ground?) on the relay of the fan. Once the fan comes on does the black wire become hot, hence being the same voltage as the pink wire and de-activating the relay?
Le Mans Master
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From: Sachse Texas
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Re: Electric waterpump wiring help needed! (Bob86ZZ4)
Mine did the same thing so I wired it to the accessory wire inside the center console bacause I knew that one to be hot when I wanted it on.
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Re: Electric waterpump wiring help needed! (mn_vette)
Sorry, I mis-read your post. If somehow your wire is becoming hot then yes in fact it will drop the relay. All of my aftermarket wiring is tied to a single ground, somewhere on the frame. I took a heavy wire and attached it to the frame in the same place some stuff was already grounded, and ran it over to where my AIR pump used to be and it hits a terminal block. I use it right now exclusively as a "ground distribution" block. Now any time I need a ground I know where to connect it and I know it's a good solid ground.
Thread Starter
Melting Slicks
Joined: Jan 2002
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From: Jackson MI
Re: Electric waterpump wiring help needed! (Nathan Plemons)
True that all the grounds are tied togther, but I don't think the thick black wire is a ground at all
Ok, I think I've got this thing figured out
Relay's: Back to basics
4 wires comming out of them. Activation, Activation ground, Power, and Device
With the fan relay the Activation line is the pink wire, the Activation ground is the green wire (ECM controlled between 12V(fan off) and ground(fan on)) the power is the red wire(+12) and the Device is the Black wire
When the ECM determines that the fan should be on the green wire becomes grounded and there is a 12V difference in the Activation and Activation ground causing the relay to close making a short circuit between the Power and the Device.
In my messed up relay I had the Device of the Fan relay as the Activation ground on my Water pump relay so when the fans went on the Activation ground went to the same voltage as the Activation causing the relay to turn off killing the water pump. Solution: find a real ground for the Activation ground and all should be well. I'll have to try this tonight and prove my theory. And yes I am an engineer :D
Ok, I think I've got this thing figured out
Relay's: Back to basics
4 wires comming out of them. Activation, Activation ground, Power, and Device
With the fan relay the Activation line is the pink wire, the Activation ground is the green wire (ECM controlled between 12V(fan off) and ground(fan on)) the power is the red wire(+12) and the Device is the Black wire
When the ECM determines that the fan should be on the green wire becomes grounded and there is a 12V difference in the Activation and Activation ground causing the relay to close making a short circuit between the Power and the Device.
In my messed up relay I had the Device of the Fan relay as the Activation ground on my Water pump relay so when the fans went on the Activation ground went to the same voltage as the Activation causing the relay to turn off killing the water pump. Solution: find a real ground for the Activation ground and all should be well. I'll have to try this tonight and prove my theory. And yes I am an engineer :D
Pro
Joined: Sep 2001
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From: Phx/but its a dry blast furnace kinda heat AZ
Re: Electric waterpump wiring help needed! (mn_vette)
I sure wish someone would come up with a snap-in harness for this, to make this mod easier and foolproof. :crazy:
Thread Starter
Melting Slicks
Joined: Jan 2002
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From: Jackson MI
Re: Electric waterpump wiring help needed! (mn_vette)
Re-wired last night and haven't had any problem since. I hope this post will help some poor sucker that makes the same mistake some day.
Thread Starter
Melting Slicks
Joined: Jan 2002
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From: Jackson MI
Re: Electric waterpump wiring help needed! (Ramrod92)
How about posting a drawing showing exactly how you have it wired in now? :cheers:
the green wire on the drawing is comming off of the pink wire in the fan relay, everything else should be self explanitory