That sounds more like the starter relay. It's a long-running trope with Toyota pickups and 4runners. The earlier models didn't have a starter relay, so the full power was going through the starter switch. Later models like yours came with a factory starter relay. Given the age of the vehicle it would be wise to just replace it with a new one. An OEM Denso unit is cheap on RockAuto, like $15 + ship, or direct from Denso for about the same price.
https://www.rockauto.com/en/catalog/...rol+relay,3804
https://www.densoproducts.com/denso-567-0021-relay

 

[QUOTE=13Swords;52501471]The "split" you mention is likely a model year change-over thing. In the new vehicle business (at least as far as it goes in the US) vehicles that are completed from July forward are usually the next year's model, e.g. Made July 1991 is likely a 1992 model. If you have specific info that the switch fits a vehicle made in June 1991, it's most likely going to be correct for a 1991 model.
The only other difference I found is a difference between US built trucks and Japanese built trucks, a difference in plug format and pin arrangement. But that difference doesn't show up in parts lists until the 1993 model year.

I believe you are correct that there were some changes around this model year, and there were two ignition switches (and as you said the tow had different pin/plug counts - maybe 5 and 7 pins ??, as well as the pigtail/plug configurations). It's been several months since researching this info, but I do know that some of the sites I was looking at for the ign switch provided me with conflicting information as to which was the correct one for my vehicle.


Thank you for this information. I actually know this is correct on most older vehicles and not sure why I made this statement (or misstatement). I am not sure about the newer keyless entry and immobilizer technologies, but I agree that the switch was not dependent on the key, but the cylinder was.

Short story: We had a 1993 Ford F150 that had an ignition component malfunction which turned out to be a actuator/lever that connected the cylinder to the ign switch module further down in column. Although it would start and run, you could not turn it off by using the key cylinder (manual tran so we just "popped" the clutch to kill it). Apparently this was a very common problem for several Ford model years. The aftermarket replacement part cost only $10 - $15, but to replace it required the entire column taken apart to access the area where the lever was located. We were not sure we wanted to invest that much effort in a vehicle that had "two wheels in the junkyard" already. Our final solution - we found an entire column for $150 and replaced the it (and switched out the cylinder to maintain the keys we had). Given that the truck did not last very long after this repair, in hindsight it may have been a better option to have kept the cylinder and threw away the truck.

Again - thanks for correcting my mistake.

 

Not a problem, it happens, even to me, and I'll always be the first to admit it when I discover it.I have heard that more "modern" vehicles have had a similar problem to that Ford you describe. One more reason I'm keeping my '78 going as long as I can.

 

@13Swords Thank you for helping out! Seems to be the starter relay was the culprit. I picked one up for around 20 bucks plugged it in and my truck fired right up. Good advice to swap them out on these older vehicles as a preventative maintenance for sure

 

Great to hear and glad that apparently was the culprit. Happy to be of help.