Questions and Answers

Toyota 4Runner Head Lamp Relay Q. Vincent Ciulla, I have a 1995 Toyota 4Runner SR5, 3.0 liter V-6 4WD, automatic transmission with 101,000 miles. I have two electrical problems that I have not been able to figure out. The first is my dash and gauge lights went out after I replaced my factory radio with an after market. The power fuse for the gauge light blew and it also controls the rear running lights.

After replacing it the rear running lights came back on but the gauge light did not. I do not know where else to look. Additionally my high beams started to delay turning on when I activated them I could hear the relay turn when they finally went on, but now they are completely disabled. Do you know where the relay is? The guy at the Toyota dealership parts department could not tell me and end up selling me the wrong relay.

I would take the truck to a mechanic but as a student I am strapped for cash. Any help would be greatly appreciated. P.S. how do you test, with a multimeter, if a relay is working?

Thanks much,
Wil

A. he head light relay is located in the relay box, directly behind the battery. The relay box cover has a 'map' that will tell you which one it is.

Toyota used three different types of head light systems on that vehicle so without knowing which type you have, I can offer you little advice. Since this happened as a result of installing an aftermarket radio, I would think the problem is in that area rather a problem with the headlight system.

Since you are concerned about the head light relay, we'll talk about that type of relay.

In this instance the relay is a very simple one, inside the relay there is a coil and magnetic switch. Sending power through 3 and 4 will energize the coil creating a magnetic field. This magnetic field pulls the switch closed completing the circuit and allowing power to flow. When power is removed from the coil, the magnetic field collapses and a spring opens the magnetic switch.

So to test this relay, you need to use an ohmmeter to check for continuity in the coil by connecting your test leads to 3 and 4. There should be continuity. An open indicates a bad coil. By applying power and ground to 3 and 4 should cause the relay to click, indicating the magnetic switching.

Connecting your ohmmeter to 1 and 2 should show an open when the coil is not energized and continuity when the coil is energized.