First Time Threader
1987 Pickup, automatic transmission would not start. Starter motor would only single click. Check battery, bench test starter, and all are okay. Happened to notice that when key was on, while fumbling with starter wires, a clicking noise came from transmission relay up in driver side cab. Pulled relay and now the starter fires, and engine starts. So, now I have an engine that starts but need a transmission relay that has been discontinued. any ideas of how to repair relay or where to purchase or some other work around. discontinued relay is Toyota 89531-28010. Any guidance would be appreciated.

 

That area is known for water intrusion. I'm not saying that' that's the trouble, just offering a possibility.

IF the relay isn't in too bad a shape, you may be able to pull the casing off, and clean the contacts. As long as the coil is still functioning properly, and the contacts switch back and forth properly, cleaning the contacts off with some real fine grit sand paper, or ruby cloth, may solve your entire problem. Just don't sand the contacts down so far they disappear.
You should also ensure that the arm that switches the contacts isn't bent, no longer making correctly when it switches. It's made of VERY thin metal, so be very careful if you do need to bend it. Be gentle. A small pair of needle-nose pliers, or even a pair of forceps, if you have them, will do the trick.

Hope this is some small, help.
Pat☺

 

Thanks 2ToyGuy.
I pulled out and inspected the relay.. It appears to be in good shape. I see no evidence of moisture. This vehicle had spent most of its life in desert southern utah. I’m wondering if the wire into the sensor that goes to the transmission relay might be the problem. The light green sensor clip is in the exhaust manifold area, under the air filter. It is when I wiggle the sensor wire that the relay trips back and forth. So, maybe not the relay? Once I was able to move the wire to a stable location, and the starter engaged. I’ve not been unable to duplicate this. Not sure what the sensor or connector are called. Maybe this is the problem. Thanks.

 

What I thought was a green sensor is the thermal switch. I can buy a new oem switch but fear that the defect is the top connector since the clicking occurs when the wire is wiggled. Any thoughts on this?

Switch with top connector and wire. Switch hole in background.

 

Any update?