I have to admit I am having a bit of trouble understanding what you are saying, could you check your spelling before posting please?
I have an ex-2.5NA D converted years ago to 300TDi using a LRGP re-power kit and until recently I had retained the original (non-locking) ignition switch with manual "heat" position but just a few weeks ago fitted a 300TDi ignition switch c/w lock. The trick was that with the 300TDi fitted the glow-plugs are on a timer-relay operated by turning the switch to "on", the "heat" position was used to operate the starter solenoid (the second sprung-loaded switch position was not used). Glow-plug warning light went out with the timer as per 300TDi set-up.
I have listed below how mine is wired up and yes, you must retain the starter relay. Really it was just a case of looking at the two wiring diagrams and seeing what each tab did on the two ignition switches to work out what went where. As the older switch was designed for current carrying I decided to use a relay for the +VE feed on the later switch, might not be necessary but the later switch uses 6mm terminals whereas the earlier one uses 10mm.
Terminal numbers relate to 300TDi switch:-
1. Battery feed (thick brown via relay).
2. Yellow/black (thick glow-plug feed now used to operate timer-relay).
3. White/red.
4. White.
5. Yellow/black (warning-light).
6. Earth.
By no means certain that this will match up with what you have but it works perfectly on mine.
