fan relays, 95 monte carlo
Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=107591
Printed Date: July 18, 2025 at 7:41 PM
Topic: fan relays, 95 monte carlo
Posted By: my95z34
Subject: fan relays, 95 monte carlo
Date Posted: September 21, 2008 at 6:29 PM
Ok, my 95 Monte Carlo has two electric fans on the rad. Only one is normally used. I want to make it so both of them come on at the same time. To do this I want to jump the two relays. So when the car sends the signal to the relay to turn on fan #1, that same signal goes to fan #2's relay turning that fan on too.
Now, which leg do I use? It has 4.
Thank you!
Replies:
Posted By: my95z34
Date Posted: September 26, 2008 at 9:33 PM
It's not a technical relay question. Just a general one, which leg of a relay is the one that turns it on?
Thanks.
Posted By: i am an idiot
Date Posted: September 26, 2008 at 9:56 PM
It will be one of the small wires on the relay. You may have to use a meter to determine what you need to do.
Posted By: my95z34
Date Posted: September 26, 2008 at 9:59 PM
i am an idiot wrote:
It will be one of the small wires on the relay. You may have to use a meter to determine what you need to do.
There aren't any wires, just legs off the relay.
They are labeled 85, 86, 30, and 87
Posted By: i am an idiot
Date Posted: September 27, 2008 at 9:42 PM
85 and 86 are the coil of the relay. If you apply ground to one terminal and power to the other, the relay will energize.
Posted By: my95z34
Date Posted: September 27, 2008 at 11:08 PM
i am an idiot wrote:
85 and 86 are the coil of the relay. If you apply ground to one terminal and power to the other, the relay will energize.
Ok, then it shouldn't matter which I jump, between 85 and 86?
Posted By: i am an idiot
Date Posted: September 28, 2008 at 2:07 AM
When does the second fan come on? Most vehicles have one fan that comes on with the A/C system, and the second fan comes on to prevent overheating. If you connect the second fan(the one that keeps car from overheating) to the A/C fan, and don't have the A/C on, when stopped in traffic, you have oveheating issues. If in the winter time you are using your defrost with the A/C compressor on, both fans turning will keep your car from warming up.
If you still insist on trying this, you will need to figure out how the original equipment works, meaning do they have ground always on 85 and switch power to 86 to turn fans on, or there is constant on 86 and they switch ground on 85 to turn fans on. Once you figure that out, you can use a diode so that when relay 1 is energized it will energize relay 2. But doing it this way, fan 2 will still work as it should to prevent overheating.
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