Won't start in park, starts in neutral

[jangell]

My car won't always start in park (sometimes it will, but often not), but it starts in neutral with no problems. I'm fairly certain that the problem is a misalignment between where the park position is on the shifter and where the park microswitch is, and thus the start inhibit relay isn't being triggered and the starter won't run.

The thing is, I have no idea where that microswitch is, or how to adjust for it.

I have no problems putting it in reverse, neutral or drive; it's just that I can't seem to move the shifter quite far forward enough to engage the park. I'm thinking the switch is in the transmission and I just need to adjust the shifter linkage slightly, as per G:05:02 in the Workshop manual, but I wanted to check before I start messing with that.

Thanks!

-- Joe

[Jonathan]

The problem might be the collar on the shifter shaft has spun out of position and it is preventing you from pushing it all the way up.

Looks like you have an early VIN and so would have the early shift lever design. You can see what I mean in the 2nd photo in this post (http://dmctalk.org/showthread.php?10336-Assorted-Helpful-Technical-Photos&p=165448&viewfull=1#post165448).

That little brass coloured collar is what moves along the ridges in the shifter box and lets you find each gear position. You are supposed to be able to go from some positions to another without pushing the shift interlock button (like from N to D), but not go from N back up to R. When you push on the shift interlock button on the underside of the shifter handle, that whole lower plastic shaft lifts up and lets you move it freely from one position to another. The collar is held onto the plastic shaft with a tiny screw in one end and it pinches it to the shaft.

What can happen is either that screw gets loose or the whole shaft just rotates because it is separate from the top plastic portion. Mine is just a snug fit, but if you push a little on the shift lever without pushing the button, it will move from one gear to the next and spin that collar out of the way. If it gets spun out of the way, but now that bulkier end is pointing up, you don't have enough room to get all the way up into park. I suspect this is what has happened in your car.

You can remove the top shifter plate and have a look. You need to remove the shifter handle first by removing two screws that you access by moving the shifter all the way down to 1 (with the car off and parking brake on). Then pull apart the two plastic halves of the shifter handle. Be gentle, as it's made of some pretty cheap plastic. You will see how it goes together with that button being a metal part held on to the shaft with a nut. Remove all of that and the spring that's under there and set it aside. Once that is off, you can lift the shifter plate over the bare shifter shaft. You'll now be able to see how the lower shaft rotates and so does the collar. Put it back aligned where it needs to be and then test to see if you can start your car in park before putting it back together.

You can clean-up the area underneath that shifter panel too if you like. If you've never been in there, you'll probably find all kinds of odd stuff. The PRND21 lightbulb is there too if that needs attention. Go easy pulling it put of the plastic underside of the shifter plate as it's probably in poor shape.

[David T]

The switch IS in the transmission. The adjustment procedure on G:05:02 is the place to start. Can't hurt to take the shifter mechanism out and clean and lube it. With the linkage disconnected the shifter should move all the way into Park unless something is caught in it preventing you from moving it all the way.

[jangell]

Thanks. I should give a bit more background on my shifter setup:

About 10 years ago my shifter snapped in half. It turns out the pivot arm ("bellcrank lever" in the Workshop Manual) had started to seize, and it was getting harder and hard to put it into gear, or reach park all the way. I didn't know as much about how to work on the cars as I do now, so I just kept forcing it, and eventually it simply snapped. This was fun, because the car was stuck in drive and I was 100 miles from home. DMC CA talked me through wiring up some jumpers to bypass the start inhibit relay so I could get back.

If I remember correctly, I replaced the entire shifter housing (part 105427) as well as the bell crank lever (100824), after I managed to get it off, and sanded the rust off the pivot point.

The shifter does move all the way to the end of the shifter plate to the "P" position. However, the switch doesn't seem to engage.

As for the brass ring, even though the shifter moves all the way to the end, it could well be the problem. My shifter button has never really worked right, and doesn't spring properly (the spring's there, though, part 101919; I'm not sure about the lower spring, part 105434; I'll check for that), and the button never releases, so I just pretend that it doesn't lock. I can still feel the shifter hit the detents for the different positions, so it doesn't bother me that much. Because of this, I didn't bother to re-secure the brass ring you mentioned when I re-assembled it recently. It seems quite likely that it is blocking the shifter movement just enough that the the switch won't engage. I'll check this first, and check for the second spring while I'm in there.

If the brass ring isn't the problem, I'll try adjusting the shifter linkage next.

Thanks!

-- Joe

[jangell]

The lower spring is indeed missing from my shifter. Of course it’s no longer in stock at DMC. For now I’ve just moved the brass ring high enough that it won’t get stuck on the “steps”, and just continue not to use the button. I also oriented the ring so that it won’t hit anything that would limit the shifter flow.

If I push the shifter all the way forwards with the shifter plate off, I can start the ace. But once the plate is back on, the car won’t start no matter how far forwards I push the stick. I even tried pushing it forwards while turning the key.

Looks like it’s time to adjust the shifter linkage. I think it only needs a very tiny adjustment.

— Joe

[Ron]

+1 on following G:05:02.
WRT to the starter, the only difference in Park and Neutral is which of two cam lobes presses one of the buttons on the multi-function switch inside the transmission. It would be rare for the cam or switch to have a problem. (When you get to step#4, if the tube will not slip over the bellcrank mounting stud BEFORE loosening anything, there's a problem with the shifter/linkage.)

[David T]

With the history and how you were forcing the linkage you should go over every bit of it to make sure nothing else is damaged, bent or broken. Once you do that and get it working smoothly you can try adjusting it.

[Jonathan]

Ok, I'll let you run with the workshop procedures and the advice both Dave and Ron have given you. My suggestions are probably a little more relevant to a car that's still all factory or mostly unadultered. Not saying yours is all heavily modified away from stock, but without having a good idea what isn't "typical" on your car, I'll just step aside for the time being.

[Ron]

^???^
I'm confused... I think it is probably the shifter mechanism...due to one of the things you mentioned, J.

[jangell]

The shifter linkage adjustment did the trick. It needed one full turn counterclockwise, and now it starts from park no problem.

In the 10 years since I broke the shifter, I’ve had to have the transmission replaced, so I’m pretty sure that it’s in good order now. Probably. :) I think the misalignment today is from the engine swap that I’ve been slowly doing, and I didn’t quite have it right when I put the transmission back in.

Johnathan, checking the shifter brass ring was a good call — it wasn’t aligned correctly in the first place and would have caused troubles eventually.

Thanks for the help!

— Joe

[mike123]

+1 on following G:05:02.
WRT to the starter, the only difference in Park and Neutral is which of two cam lobes presses one of the buttons on the multi-function switch inside the transmission. It would be rare for the cam or switch to have a problem.

Joe's issue was that the car would start in Neutral but would not start in Park... but what if it won't start in either Neutral or Park? Would that indicate it might be the cam or microswitch?

[jangell]

Joe's issue was that the car would start in Neutral but would not start in Park... but what if it won't start in either Neutral or Park? Would that indicate it might be the cam or microswitch?

That does sound like it's somewhere in the start inhibit circuit. I'd probably start by testing the relay and its socket in the relay compartment, since that's likely the easiest place to do a quick test form.

-- Joe

[mike123]

Sorry, I did mean to provide some additional info. Yes I tested the relay and socket and the white/yellow wire female spade does not have ground (like I think it should) when I am having starting issues. The relay itself is only a few months old and swapping it made no difference. In all testing, the shifter has been clearly in Park or Neutral as best as one can be certain from the driver seat.

In reading some advice on Facebook again (things make 10% more sense each time), it seems like it could be the switch but could also be the bulkhead connector (which looks clean to me) or the connection to the switch. So I guess I will try to test those things before assuming it is the switch itself.

[mike123]

Wiggling the bulkhead connector actually worked! The car started after I wiggled it.

I notice that the male end of the red connector (which contains the yellow/white wire that is causing me all the problems) is different than all the others:
70171

Interestingly I have only found four other close-up images of this connector on other cars. VIN 16028 has the same red plug style as mine, as does maybe Joe's (see below), and another car (VIN unknown) and the DeLoreanTech YouTube channel car, have a red plug that matches all the other plugs, e.g. clips with holes in them and a rim around the male piece.

And Joe, your red connector appears to be the same style as mine, but maybe in a different position: https://www.tmproductions.com/repairs-and-maintenance-blog/2018/10/25/modern-bulkhead-connector

[jangell]

Well, I have an EFI conversion, so I packed all the old wires into the large Deutsch connector in a custom bulkhead plate (basically a piece of plastic that I heated so I could put a 90 degree bend in it to replace the original metal plate). The automatic transmission and tail light connectors are the only original connectors still there, which is why it's in a different position.

I also have an early VIN (767), but that doesn't seem to explain why my connector might be different, since you cite other cars with later VINs having the same connector. I think they're functionally the same, just that there's an extra lip. I might help with weather sealing a little.

Still, these connectors aren't not the greatest Some kind of conductive grease on the pins might help (not dielectric grease -- that's an insulator), or you could remove the female connector, remove the pin, and carefully crush with pliers it so it's SLIGHTLY tighter. It is easy to damage it by oversqueezing, though (there's a point where it feels like you're not crushing enough that suddenly becomes the point where you've crushed it completely), though, plus it's not that easy to get the pin out in the first place.

The hack option is to jump around it. Say, adding a short run of wire with a spade connector to the relevant wire no the connector, which would plug into another wire on the back of the bulkhead connector. But that's pretty ugly and I'd probably leave it as a last resort (say, after you ruin the female pin by trying to crush it).

-- Joe

[mike123]

Eyeballing the connector and the extremely minor movement that led it to go from Not Working to Working also makes me wonder if the loose connection is further down the line of the white/yellow wire. And maybe wiggling the red connector really just wiggled the wire at the actual problem site.

My usual and very amateur method for loose friction pins is to just put a thin coat of solder over them, but the pin here seems fine. It is either the red plug is not going in far enough, even when clipped... or the problem is further down the wire.

The car is going to Crystal Lake next month, so there may be something obvious that they see that I cannot. And until then, I now have 3 ways in my repertoire to solve the no-start problem:

1) wiggle red plug while someone turns the key
2) jump the starter relay with a little double spade wire
3) jump the starter itself by giving it electricity via jumper cable

Still, I will be very excited when/if this issue can be definitively found and fixed. It is the only issue I have had with the car so far.

[Bitsyncmaster]

Eyeballing the connector and the extremely minor movement that led it to go from Not Working to Working also makes me wonder if the loose connection is further down the line of the white/yellow wire. And maybe wiggling the red connector really just wiggled the wire at the actual problem site.

My usual and very amateur method for loose friction pins is to just put a thin coat of solder over them, but the pin here seems fine. It is either the red plug is not going in far enough, even when clipped... or the problem is further down the wire.

The car is going to Crystal Lake next month, so there may be something obvious that they see that I cannot. And until then, I now have 3 ways in my repertoire to solve the no-start problem:

1) wiggle red plug while someone turns the key
2) jump the starter relay with a little double spade wire
3) jump the starter itself by giving it electricity via jumper cable

Still, I will be very excited when/if this issue can be definitively found and fixed. It is the only issue I have had with the car so far.

Get a mating pin and crimp it on a wire. Then use that pin to feel the tension pushing and pulling the pin in and out of each mate. You would be surprised of the difference between a good pin and bad one. Do it for the relays and the bulkhead.

Now there are also bad crimps. To find those you wiggle the wire to test. Better if you can do it while the problem is powered.

[mike123]

That is a good suggestion, thanks Dave. I will try that with the pin. And regarding the crimp, I may be able to eyeball that or wiggle-test it.

EDIT: Actually on the crimp side of things, I ordered a $7 pin removal kit on Amazon. I should have one anyways I guess. But that should allow me to pull out that yellow/white wire pin and take a close look at it.