Microswitch for Auto

[lazabby]

I have a question regarding the microswitch next to the throttle spool. The swich has the metal plate which depresses two plungers. It appears that the upper plunger is working properly but the lower plunger is stuck. What does the lower plunger do? I've had some starting issues in the past few months and I'm wondering if this microswitch has something to do with it.

[Ron]

The one with a Light Green with Green stripe wire is for the Automatic Transmission Kick Down.
The one with a Light Green (no stripe) wire is for Full Throttle Enrichment.

[lazabby]

The one with a Light Green with Green stripe wire is for the Automatic Transmission Kick Down.
The one with a Light Green (no stripe) wire is for Full Throttle Enrichment.

Thanks. I think that's the information I needed. The workshop manual wasn't clear. I'm pretty sure the solid light green one is the one that goes to the plunger that is stuck. I haven't looked at the wiring diagram to see where it was going but I think you've confirmed the issue that I've been having.

Somone with a manual thought his microswitch had only one plunger. Are there two different microswitches depending on the transmission type of the car or is there only one with one of the plungers (auto transmission portion) being disabled on the 5 speed Deloreans?

[Dangermouse]

They are actually two separate, but identical microswitches.

The manuals don't have the one for kick-down. (the connector for it is un-used)

If you take them off, you may be able to spray contact cleaner in the stuck one and unstick it. (make sure the little plunger doesn't fly off when you remove them ;) )

I had a sticky one and a stuck one. I was able to free up the sticky one, but never had success with the stuck one, so I replaced it. They are surprisingly costly btw.

[lazabby]

They are actually two separate, but identical microswitches.

The manuals don't have the one for kick-down. (the connector for it is un-used)

If you take them off, you may be able to spray contact cleaner in the stuck one and unstick it. (make sure the little plunger doesn't fly off when you remove them ;) )

I had a sticky one and a stuck one. I was able to free up the sticky one, but never had success with the stuck one, so I replaced it. They are surprisingly costly btw.

I'm looking at going to EFI so I may not need the one controlling the throttle. I'm still researching that. I may see if I can spray cleaner on it as you suggest. Or you can come over and work on it next week when you're here! :)

[David T]

The 2 WOT micros have no effect on idle unless the one for full enrichment is stuck on. Disconnect it and see if that helps. Check the CSV system for starting issues.
David Teitelbaum

[lazabby]

The one with a Light Green with Green stripe wire is for the Automatic Transmission Kick Down.
The one with a Light Green (no stripe) wire is for Full Throttle Enrichment.

The wires to the top plunger are black and the ones to the lower plunger are green.

[lazabby]

They are actually two separate, but identical microswitches.

The manuals don't have the one for kick-down. (the connector for it is un-used)

If you take them off, you may be able to spray contact cleaner in the stuck one and unstick it. (make sure the little plunger doesn't fly off when you remove them ;) )

I had a sticky one and a stuck one. I was able to free up the sticky one, but never had success with the stuck one, so I replaced it. They are surprisingly costly btw.

I was able to spray the contact cleaner on it and get the lower plunger to "plunge". Haven't taken the car for a run yet though to see what effect if any it will have.

[Ron]

The wires to the top plunger are black and the ones to the lower plunger are green.Rub some cleaner on the wires and look closer -- One should have a darker green stripe.
...There are differences in the wiring for different years, but all schematics I've seen are the same here. In any case, two black wires going to the same switch makes no sense (Black should always be ground!).

EDIT: Just in case the harness has been altered and taped over, or whatever, get a meter, unplug both switches and ensure that both Black wires do go to ground. Then release the locking tab on either of their terminal ends with a tiny screwdriver and swap it with either green wire.
You can check the Full Throttle Enrichment switch by pressing the switch(s) down at idle and listening for a change in the engine -- You must do this test after the engine is warm (since the Thermal Throttle Enrichment uses the non-striped green wire also...).