Your Dodge vehicle uses relays to control the flow of current in various electrical circuits and their components, much like a regular switch. They are very efficient switches, since all you need is a small current to control a larger current to power components. However, electrical current may burn terminal contacts or break the internal coil after years of service. Only a series of simple tests, found in this practical guide, using an ohmmeter and jumper wires will let you know whether you need to replace one or more relays on your Dodge model.
Four Terminal Relays
Identify the two control circuit terminals connecting to the coil inside the relay and the two power terminals that connect with the contact points. Most relays are marked on top to identify these connections. If the relay is not marked, look at the connections that hook-up to the relay terminals. The two thinner gage wires connect to the control circuit terminals and the two thick gage wires connect to the power terminals. If this does not help, consult the wiring diagram on your vehicle service manual to identify these terminals.
Check for continuity between the two power terminals. Set your ohmmeter to the lowest ohms range or continuity setting. Then touch the relay terminals with your ohmmeter probes. There should be infinite resistance or no continuity. If there is continuity, replace the relay.
Connect a fused jumper wire between one of the control circuit terminals on the relay and the positive terminal of the car battery. Then hook-up another jumper wire between the other control circuit terminal on the relay and the ground terminal of the battery. You should hear a click sound as you complete the connections. On some relays, it is important to observe polarity. Reverse the connections between the two control circuit terminals. If you still do not hear this click sound, replace the relay.
With the test connections in place on the control circuit, check for continuity between the two power terminals on the relay. Your meter should register continuity now. If not, replace the relay.
Three Terminal Relays
Some relays you may have to test on your Dodge model will have three terminals instead of four. The wiring diagrams in your vehicle service manual will let you know whether the relay is grounded through its case or it is externally grounded.
A case-grounded relay can be tested the same way you did with the four terminals unit on the first section above. Just remember that the relay's case will be your ground connection this time.
On externally grounded relays, identify the battery power, control circuit and power circuit terminals. Make sure there is no continuity between the battery power and power circuit terminals. Use your ohmmeter as you did on step two of the first section. If there is continuity, replace the relay.
Hook-up a fused jumper wire between the battery power terminal and the positive terminal of the car battery. Hook-up another jumper wire between the control circuit terminal and ground. You should hear a click sound as you complete the connections. If you cannot hear the click sound, replace the relay. If you hear the click, leave the relay connected to battery and ground.
Hook-up a test light between the power circuit terminal on the relay and ground. The test light should glow. If the test light does not glow, replace the relay.
- The Haynes Automotive Electrical Manual; Ken Freund, Jon LaCourse, Mike Stubblefield, Bob Worthy and John H. Haynes; 2000
- Auto Mechanics Fundamentals; Martin W. Stockel and Martin T. Stockel; 1982
- Modern Automotive Technology; James E. Duffy; 2003
Dodge Durango Electrical Problems
Various electrical problems affecting the Dodge Durango SUV have resulted in three different manufacturer recalls. The compact Dodge vehicle that was first...
Problems With Dodge Grand Caravans
Electrical issues are one of the biggest problems among Caravans, and the power locks appear to be where the most common problems...
How to Troubleshoot the Electrical System in a Dodge Ram
eHow; Car Repair & Maintenance; Car Electrical Repair & Maintenance; Troubleshoot Car Electrical Problems; How to Troubleshoot the Electrical System in a...
Dodge Ram Starter Problems
Dodge Ram Starter Problems. ... The Dodge Ram starter relay, or switch, opens a set of electrical contacts to send an electrical...
What Is an Electric Relay?
What Is an Electric Relay?. ... Related Ads. Check It Out Why I Gave My Kid More Screen Time by Mom.me You...
An Ignition Problem in a Dodge Dakota
The Dodge Dakota, like other vehicles, relies on a complex system of mechanical and electrical components to start and run its engine....
How to Replace the Starter Relay in a Dodge Intrepid
The starter relay on a Dodge is designed to energize when the ignition is turned to the "START" position. ... View Photos....
How to Replace Your Turn Signal Relay in a Dodge Caravan
Find the turn signal hazard flasher relay in the upper right corner of the fuse box. ... How to Replace the Radiator...
How to Wire a Dodge Ram Trailer Brake From Scratch
How to Wire a Dodge Ram Trailer Brake From Scratch. ... Connect the white ground wire to the white electrical lead on...
The Location of the Turn Signal Relay in a Dodge Ram 2500
The Location of the Turn Signal Relay in a Dodge Ram 2500. ... How to Check Turn Signal Wiring. If you think...
How to Hook Up a Dodge Starter Relay
The starter relay on a Dodge is designed to energize when the ignition is turned to the "START" position. ... Related Ads....
How to Replace a TIPM Relay in a Chrysler Town & Country
Push in the tabs that hold your relay circuit board in place beneath the relay cap, ... How to Replace an Integrated...