Ricko1966
Full Access Member
- Joined
- Apr 11, 2017
- Posts
- 5,601
- Reaction score
- 9,120
- Location
- kansas
- First Name
- Rick
- Truck Year
- 1975
- Truck Model
- c20
- Engine Size
- 350
A relay needs 2 powers and 1 ground and provides 1 power out,if it is not getting both powers and a ground you won't get power out. A relay is basically a toggle switch that is switched by an electromagnet instead of by hand,it has a high amperage power in and when closed a high amperage power out. To close the switch the electromagnet has to work, it needs a 12v power and ground one if which needs to be controlled by a switch. Before you ask why they didn't just use a switch in the first place,it's because they can use a low amperage switch to control a relay that does the heavy work. Look at the relay pic below power in on 30 power out on 87. Electromagnet side 85 and 86 have to have power in and a ground to close 30 to 87Thank you all for the help I've followed the wiring diagram from the post and I have 12v up to the ac relay that I have already replaced. There is power coming in but I cant read any power leaving.
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