Yep, should be straightforward.
It is unclear to me whether the signal output of the DPFE is the same as the EVP...I tend to doubt it is, and a computer designed for one will not understand the signal from the other.
Since the computer expects EVP, I'll give it an EVP.
Another little finding...
1993 EVTM shows the clutch position switch/clutch safety switch as a single unit containing 3 electrical switches operated together, but electrically isolated:
Normally open (closed with pedal down):
1 - Joins the Start output (R/LB) from ignition switch to the starter relay (R/LB)
2 - Joins ECM pin 30 (LB/Y) to ECM pin 46/49 Signal Return (GY/R)
Normally closed (open with pedal down):
3 - Joins output from brake light switch (LG) to the 'disable' input on the cruise module/amplifier (LG)
The clutch switch pinout is given and it has 6 contacts, one in and one out for each of the above functions. Easy.
The 85...man, the 80s EVTMs really suck compared to the 90s ones (have noticed the same with my Panthers too).
The clutch switch is mentioned on a handful of pages, each time, it is depicted as only a single switch.
In the start circuit, it shows a normally open (closed with pedal down) switch connecting "start" from the ignition switch to the starter relay.
On the Electronic Engine Control pages it shows a normally open switch connecting ECM pin 11 (W/BK) to ECM pin 46 (BK/W).
On the Speed Control page, it shows a normally closed (open with pedal down) switch connecting the output from the brake light switch (LG) to the cruise module/amplifier (LG).
Poked my head under my dash. My clutch switch has what appear to be two spots for plugs to connect to it, each with 2 wires. Only one position has a plug on it with 2 wires, the ones for the start circuit.
Start circuit is easy, no real changes needed to that on its own. But the 93 ECM expects to see when the clutch is pushed. Not sure why it needs to know that, but it wants to know it.
If the additional pair of contacts on my existing clutch switch are normally open, I'll just have to track down the connector to plug onto it and that'll be easy enough to wire. If the additional pair happens to be normally closed then it won't be usable.
Alternative is trying to mount the newer clutch switch to my 85 pedal assembly, not sure what would need to go into that.
Another alternative is changing the whole deal for the clutch switch to get a constant hot input feeding two relays,
1 - triggered by the ignition switch feeding the starter relay from the constant hot input
2 - triggered by the clutch switch, closing the circuit between ECM 30 and 46/49
The relay option is the least clean looking, but probably easiest to do. Would be cool to populate a couple of the unused spots in the underhood power distribution box.
Since a remote starter is in the plans for this truck I'll have to give this some thought. In a perfect world I'd have a true neutral safety switch, not a clutch safety switch. The TK5 has an unused switch mounted below the shift tower. If it turns out that's what it is, I'll probably completely eliminate the clutch switch right out of the picture. If that's not what that switch is, well...back to the drawing board.