Blowing fuse
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=75940
Printed Date: May 29, 2024 at 3:00 AM
Topic: Blowing fuse
Posted By: ajpjr
Subject: Blowing fuse
Date Posted: April 09, 2006 at 11:28 AM
I hooked up a relay to power my electric fan in my car. Hooked up as follows:fused power from battery to post 30, power from fuse box to post 86 through switch, grounded post 85, power to fan from post 87. The switch is grounded and has a indicator light when turned on. It keeps blowing fuses when I turn it on. Using 30 amp fuse, check all wiring check the fan by hooking it up direct without fuse and it works fine. Do I need that fuse between the batter and the relay?
Replies:
Posted By: ajpjr
Date Posted: April 09, 2006 at 11:29 AM
I did ground the fan.
Posted By: electrostatic
Date Posted: April 09, 2006 at 1:27 PM
2 things come to mind. the relay has a diode across the coil and terminals 85 and 86 are wired wrong for that particular relay. or your using the wrong fuse for that fan. what are the fans specs?
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Prove your connections, use a meter!
I promise, I'll behave!
Posted By: ajpjr
Date Posted: April 09, 2006 at 1:39 PM
Hey thanks for the reply. The fan is from a volvo and I am using it on my Hot Rod so I dont know the specs. I was using 30 amp fuses. How should 85 and 86 be wired. Should I remove the 12 volts from the switch and tie that in with the battery power at the relay.
Posted By: electrostatic
Date Posted: April 09, 2006 at 3:45 PM
i just reread the posts. oops! forget that part about terminals 85 and 86.
you need to find out what the current draw on that fan is. do you have a dc clamp meter? you could measure the current draw and select the right wire guage and fuse based on that. otherwise you'll just have to wait for someone to post it. what volvo is the fan from?
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Prove your connections, use a meter!
I promise, I'll behave!
Posted By: ajpjr
Date Posted: April 09, 2006 at 4:03 PM
It one of those that was recalled because of relay problems I took off the factory relay and wired direct to fan motor. Could it be the switch setup. None of the diagrams Ive seen have power going to the switch and then to the relay I have the power to 30 post from the battery with 10 gauge and 30 amp fuse. Most of the diagrams show the power from battery to 30 post and power to 85 post joined together from same source.Then they show the switch as a negative connection only. This fan runs strong when hooked directly to battery so I know fan is good. Maybe my relay is bad. Why does it work if I remove fuse and run fuseless to 30 post directly from battery. The relay is located inches from battery so that wire is not that long.
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