ignatz

I found out that my "Circuit Opening Relay" was malfunctioning not long after buying my truck. I started calling around to the usual local auto parts stores and found out it's a specialty item available only through the dealership. I called my local parts department and was given a quote in the $90 range! Being cheap, I tried to find a better deal online and located a discount Toyota parts dealer who offered it for ~$70 and Rock Auto who had an off-brand replacement in the $45 range. All of these options were unacceptable to me so since my relay was toast either way, I decided to attempt to repair it. What follows is a loose guide since every relay will be in different conditions. I hope this helps.

Here's a picture so we're on the same page:



Carefully separate the outer black housing from the inner grey section. Mine was held in place with some small tabs and didn't take much work to pry apart. Here's what you see when you get them apart



If you look at the black outer housing, you'll notice that at some point the capacitor exploded and let it's magic smoke out which is now coating the inside. The red arrows are pointing to the missing pieces from the outer housing. In my case, I think this damage is too severe for this to serve as a permanent replacement. If you look at the right inner housing you'll see a very simple circuit. It's made up of one capacitor (130 picoF @ 25V), one resistor (1/8W Yellow, Purple, Black, Gold) and two coils. The green line shows the route of the resistor. The capacitor's negative leg points to the left. Here is a picture with the components removed



You can really see the extent of the damage in this picture. The coils are in good working shape and should continue to serve. The green line is the path of the resistor. The red line is the path of the capacitor. The resistor is below the capacitor. Here is a picture showing the backside of the relay



The green circle shows where the resistor terminates. The red lines show the fuel pump switch. If your fuel pump turns on when the key is in the on position, check that the two red lines aren't always making contact. You may have to slightly adjust the spring at the red arrow. You may also want to clean the contacts if there is build up.

This is where the service ended for me. I decided that since the outer housing was so damaged that I wouldn't be repairing this relay. I also found a local source for a used relay. If I had not found a local used relay, this relay could have been made to serve until I was able to, by replacing the capacitor and resistor and tuning the switch. I hope this helps.