Clutch Switch Bypass For Big Blue

[Gary Lewis]

Thanks!

That is an air/fuel ratio gauge.  I used it in the set-up of the EFI system and then just left it on.  Let's me see that the EFI system is doing its job.

[Gary Lewis]

Got the new relay module in yesterday and today got most of the wiring done.

Not wanting to modify any wiring on the truck or do any more wiring under the dash than I have to, I found another clutch switch connector and plenty of R/LB wire.  I cut down two male 1/4" terminals to .75" wide, which let them slip into the connector in place of the switch's terminals.  Then I made a "connector" and a pigtail that will plug into the existing clutch switch connector and then into the switch itself.  And it has a pair of R/LB wires running back to the relay module.

I drilled the box for a grommet large enough to get the pushbutton switch's connector through as well as the rest of the wiring, drilled three holes for screws to mount the module in the box, mounted the module and ran all of the wires but the ones to the LED, which is already on the truck.  Hopefully I'll get to install it on Thursday, which requires sliding the LED wires through the grommet and terminating them, finding power and ground, and installing the pigtail onto the existing wiring and clutch switch.

Here are some pics, with the first one being the finished module save for the LED wiring, which just slips through the grommet and goes into the screw terminals, and the second two being the pigtail with the left one "open" and the right one showing how the male terminals go into the connector that's on the truck.

[Nothing Special]

Looking clean!

[BigBrother-84]

Clean and precise job, as usual Gary!

[Gary Lewis]

Thanks, guys.  Just one more minor mod to make BB everything I want him to be. 😎

[BigBrother-84]

Gary Lewis wrote

Thanks, guys.  Just one more minor mod to make BB everything I want him to be. 😎

Really?

[Gary Lewis]

Well, maybe not everything when you put it that way.  I'd like him to be pretty, but if I had the needed body work done and had him painted I'd be afraid to take him the places we've gone, so I guess I'll take functionality over looks.  

[Gary Lewis]

Didn't get as much done as I'd expected today.  Had to write up a meeting for church and send the minutes out.  And I re-wired a 72 year old Singer sewing machine for Janey.

But I did get a bit done on Big Blue.  First, I undid the wiring I'd done in the box because I realized that I'd wired in the spare push button switch, but have one already mounted on the bezel.  And since the connector on that switch is so big it has to be the first thing through the hole, everything else had to cone out.

Then I took the box to the truck and tried to run the mounted switch's lead to the box and discovered that's not going to work.  The plan had been to run the wire over to the steering column and then past the trim piece and back to the box.  But the wires aren't long enough to do that.  So the plan now is to drill through the instrument bezel directly behind the AFR meter and run the wires through that hole.

However, reaching up behind the dash I could feel that there's some kind of opening there and it would be nice to hit it rather than drilling through the dash.  So I went upstairs to my spare dash panel and did some measuring.  Sure enough, the hole for the fog lights is exactly where I need to go through.  So the plan for tomorrow is to pull the AFR meter and bezel, again, drill the instrument bezel, feed the wire through, and put it all back together.  

[viven44]

I agree with this 100%. I do not want to paint something and make it perfect. Philosophically and superstitiously I always leave things imperfect in the hopes that everything stays perfect the way it is

Edit: wife says I make no sense !!

[BigBrother-84]

Gary Lewis wrote

And I re-wired a 72 year old Singer sewing machine for Janey.

I absolutely agree that Janey’s requests deserve to be treated as a matter of priority, compared to Gary’s hobbies.


There is no question about that.

Gary Lewis wrote

So I went upstairs to my spare dash panel and did some measuring.

That’s why I am always hesitating to get rid of my over-stock.  You never know the way it could be useful.

Gary Lewis wrote

So the plan for tomorrow is to pull the AFR meter and bezel, again, drill the instrument bezel, feed the wire through, and put it all back together.

Progress!

[Gary Lewis]

Morning, Jeff.  Yes, Janey's projects/requests get priority over mine.

And this was an interesting one.  The wiring to the 1952 sewing machine, a Singer Featherweight, was in bad shape.  So she ordered in a wiring kit, which consisted of a power cord and a cord to go to the foot pedal/speed control.  The two cords connect in the plug going into the sewing machine, so I took that apart to find what's shown below.

They'd wrapped the wires to make a knot large enough it wouldn't go through the hole in the connector, which provided the strain relief.  And each wire wraps clockwise around a hollow stud and nestles down in a groove, and then a knurled nut is run down on top of it.

I got it done, but my fingers were certainly sore.  The challenge was getting all three studs down in the holes in the connector at the same time.  The holes are perfectly sized to take the connector with the point of the hex pointing down, and they don't want to stay there while you wrestle with the other two.

[Gary Lewis]

Glad Janey's project went well as mine isn't.  But I guess three steps forward & one back is still progress.

Step 1: Got the hole drilled in the dash bezel

Step 2: Got the wire run through the bezel & dash & wired up in the box

Step 3: Connected the pigtail to the clutch switch, which was a major win as that is hard to get to

Step 3: Fired it up and the LED wouldn't come on - one lead was broken off of it  

That was my fault as I'd ordered the wrong kind of LED - ones w/o strain relief on the leads.  I just ordered these from Amazon and they'll be in tomorrow morning.  So I should be able to get the red one installed and maybe get this thing buttoned up.

[Gary Lewis]

Got the LEDs in & installed, and then the whole thing buttoned up - just in time to maybe take BB & the trailer to Stillwater with Steve/FoxFord33.  So no pictures yet.  But I also got the 1/2" wide black-on-clear tape for the Brother label maker, so will add a label like "Clutch switch bypass" on the bezel before taking the pic.  Maybe Monday.

And, there's a "bonus".  I'd realized before I did it that since the LED is hot when the key is on, if you push the clutch down it'll light as the clutch switch will connect the negative side of the LED to the starter relay's coil.  Obviously the .03A of the LED is no where near the 3.5A needed to pull the starter relay in, but the relay is enough load to light the LED.

Not sure I like that, but I'll bet I get used to it.  

[Gary Lewis]

As reported elsewhere, the bypass isn't working quite right.  

It starts the truck about 1/3 of the time, and when it does the LED stays on for the 10 seconds.  Another 1/3 it cranks slightly and stops and the LED blinks off then on.  And last third you hear the starter relay click and the starter acting like it is going to go and then it stops but the LED blinks off then on.

I'm wondering if the voltage to the module is dropping as I go from Run to Start and messing up the timer?  That seems to fit with the LED going off and then back on.  And the LED doesn't blink when it actually starts.

But why does the LED come back on?  If the LED is on that should mean that the module's relay is pulled in.  

Anyway, I got the label in it today, and here's a pic thereof although it looks a lot better w/o the flash.




And here's the schematic to make it easier to ponder what is going on:

[Gary Lewis]

It appears that I was right, the power is dropping between Run & Start and the relay is dropping out.  I proved that theory by breaking into the power feed and installing a diode and a 1000 mfd capacitor in the circuit.  The diode isolates the capacitor so it is only powering the module and not everything that is on in the cab, and the capacitor provides power between Run & Start - if you don't dawdle.

I'm a stubborn man, but now I'm seriously considering replacing the pushbutton with a DPST switch.  One side will bypass the clutch switch and the other side will light the LED to warn that the switch is thrown.  

[Nothing Special]

That's how I'd do it, a switch and an indicator light.  But I'm not you, so I'm not saying that's how you SHOULD do it.  What about making the capacitor/diode thing a permanent fix?  Maybe go to a bigger capacitor if the current (no pun intended) setup makes you hurry too much.

But then again, do you really need to beat the capacitor?  Or does it just cover the time you are moving the switch from Run to Start?  In other words, once you have it in the Start position aren't you powering it again?

[Gary Lewis]

Is this what you were thinking? I could turn the key to Start and then hit the red button.  That'll pull the relay in and the starter will run as long as I hold the key in Start.  (I won't need to hold it long as it starts almost immediately, although maybe not if you've killed it by lugging.  Dunno as that doesn't happen.)

I'd be able to immediately put my hand back on the wheel as I wouldn't have to hold the button.  In fact I can easily hold the wheel with my left knee as I don't need to use it on the clutch.  And maybe that is the best solution.  Hard to do accidentally but it should work reliably.

Yes, it would be fairly easy to put a diode and capacitor in the power feed to what I have now.  But I don't particularly like the red LED coming on each time I push the clutch in.  So if I went with the switch arrangement the only time the LED would come on is when you leave the switch in bypass & the key is in Run or Start.

I have time to think about this as Janey has a doctor's appointment tomorrow that will take most of the day.  And I want to solve the noise in the steering column.  Plus there's a leak in the power steering.  Last, the grandtwins arrive on Wednesday week and we may want to drive Big Blue so I don't want him to be apart.

[Nothing Special]

Not what I was thinking (but not sure if what I was thinking makes sense either).

If I'm understanding the problem correctly the voltage drops as you go between Run and Start, and then recovers after it's in Start.  But when the voltage drops briefly the timer is resetting.

If I'm understanding that correctly the capacitor will keep the voltage from dropping while the key is moving between Run and Start so the timer won't reset.  And if I'm not understanding it correctly then maybe this is a bad idea that leads to a good idea!


And I would definitely not accept a "solution" that required me to take both hands off the steering wheel.  In many off-road situations you won't be able to hold the wheel still with your knee, especially since the engine won't be running and you won't have power steering.  You might even have trouble holding it with one hand.

[Gary Lewis]

You are understanding correctly.  Turn the key to Run and press the button to start the timer, the relay closes, and then turn the key to Start.  But the voltage goes away and the timer resets and the relay opens.

However with enough capacitance the voltage stays up.  I tried two 1000 mfd capacitors in parallel and that combo worked the majority of the time.  One of them works maybe 2/3 of the time.  So it would take a bit more than that to make sure it works every time.

I think it is time to drop back to a simple DPST switch with the LED on one side and the clutch switch on the other.  It'll work every time & won't light the LED when the clutch goes in every time, which is annoying - especially at night.

As said, I won't get to that for a bit as I have other things going on, but right now that seems to be the best plan.    (You were right.  )

[Nothing Special]

Gary Lewis wrote

Not that I'm trying to avoid being right , and I'm a little rusty reading automotive schematics.  But if you put a diode in the wire between the "top" side of the clutch switch and the "COM" terminal on the junction block I'm thinking that would still allow the signal from the ignition switch to go through (when the timer relay is closed) but would not allow the LED to ground through the clutch switch and starter relay.  So would that avoid the annoying LED shining when you hit the clutch?  Or am I rustier than I thought?