Hey all. I'm rewiring my '81 Toy truck and came across an extra all black wire that is on the ignition switch. All other wires agree with the wiring diagram and their lug marking, but this black wire. It's lug marking is ST. Any help would be appreciated.

 

Starter solenoid.

 

My diagram shows the Black/White wire that goes between the starter relay and a ignition switch Start position. Doing a continuity check proves that. There is no continuity from that black wire to any other wire on the switch. Still Stumped

 

Check for continuity between st1 and st2 (B-W to B)

 

No continuity between ST1 and ST2 in any position of the switch. Should there be? Where does this black wire from the ST2 supposed to be hooked up? Not on wiring diagram. Thanks

 

You want to probe the harness and not the switch.

Here is some basic Toyota ignition switch data, which hasn't changed much if at all between the seventies and oughts. Am1 contacts IG1 and ST1, AM2 contacts IG2 and ST2.

In a few schematics I have ST1 is listed as B-W(B) and I expect ST1 and ST2 are joined in the dash harness (hence me suggestion to check if your dash harness ST1 is spliced to ST2) what this does is splits the switching current between two terminals in the ignition switch. This is relevant because of the "cost cutting" step of the design process where the starter relay was removed in the eighties or miswired subjecting the ignition switch to the full load of the starter solenoid.

Somewhere in the late nineties early 2000's they moved the starter (solenoid) relay to ST2.

In short you want to check the subharness of the the steering wheel area if these two signals are seperated, and then check the body harness if they are connected down stream of the connection at the base of the steering wheel.

If you don't find an interconnect in either of these you can strobe (connect multimeter to dash on ST2, and drag other lead across the chassis harness connection which is IG# or something like that in the kick panels untill you get a tone).. The only.other way to go is "fox and hound" where you attach a signal generator to one end (ST2 at the dash) and run the RF detector around the harness.
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Thanks everyone, got answer from Corey(Slacker)