93 k3500 SES light and wiring issues
 

Hey guys i got this truck in November and been having the SES light on at start up and stays on tell i have drove it for sometime. i dont notice any change in performance when its shuts off. but it does come back on at stop and off as soon as accelerate. The wiring on this truck has messed with and its obvious someone didnt know the basics of wiring.. like the cigarette lighter the orange + was cut and spliced into a +wire off batt.. huu. only 3 glow plugs had wires on them. just all f***ed up. so anyways i was changing the injectors the other day and found more wiring all rigged. Now i am new to diesel motors this is my first diesel. i am very familiar with these trucks and the gas motors. So you know how on the 5.7 tbi when you go to time the motor there is that single wire you disconnect on the pass side just below the +wire junction. That wire on my diesel is not connected to anything its just cut after the connection. So my question is, is that wire do the same thing on diesels as it does for gas and if so what is that supposed to connect to.
the SES light i have got a 18 code but cant really find anything describing what the 18 code is.my guess tho the SES is due to the wiring issues..

Also if anybody has a wiring diagram for the 93 6.5td automatic would be awsome i cant find anything for 93 evwrything is post mechancal injection.

On a tbi that wire is for the timing advance. I'd assume it has no function on a diesel.

ya shuts the cold advance off or something alone those lines. ya as for diesel not sure. i would assume its got to do something? Due to there being both ends of the connectors. one side is cut about a foot or so past connector. but with the wiring i have come crossed so far wouldn't supersize if someone rigged something off the connector.

IIRC that wire is from a sensor on the back of the passenger side cylinder head and is used for glow plug activation and fuel heater?

The ses light on the 93 is of little value since only the trans is controlled by the ECM but go ahead and google "paperclip code check" and let folks know what trouble codes might be in play with your truck?

well if that what that connector is for then it must of been rewired some other way then... i have tried to pull codes sometimes i get no codes and sometimes i get code18 witch does not seem to exist as a TC.