Tom442

10 Amp fuse should be good for that too...correct?

Tom
68 442
70 F85

Hoffman2099

Hey guys, I'm having trouble getting power to the choke. I used a digital multimeter and with the key just turned to the accessory position the multimeter reads 2. something can't remember the exact read out on the choke. But when I start the car and use the multimeter on the choke terminals it reads -0.00 and it's not even working. Anyone know what might be the problem? Here are some pictures of everything. Thanks
http://i58.tinypic.com/23ifnzl.jpg


http://i60.tinypic.com/2i1jj13.jpg


http://i57.tinypic.com/2vmfr60.jpg


http://i57.tinypic.com/2co5usx.jpg


http://i60.tinypic.com/33e0hfc.jpg

MDchanic

Well, first, why don't we have a look at those pictures:











- Eric

MDchanic

Okay, having reviewed the pictures, I can say with certainty that I have absolutely no idea what you did, as I cannot follow the several wires that are the same color (either red or black), through their bundles, past the gaps in the photographs, to their destinations.

Follow the diagram in the thread that Joe Padovano posted about his subject, and you can't go wrong.

- Eric

Hoffman2099

Sorry about that. Here's where the wires go. The oil light gets power and comes on but the choke doesn't come on.

MDchanic

Okay, first, this IS Joe's thread. I hadn't even noticed.

Second, you now need to test your circuit to see where the problem is.

Check for 12V between the terminal you labelled "To Alternator" and ground. It should be there.

Start the car to bring up the oil pressure.
Check for 12V between the terminal you labelled "To Choke" and ground. It should be there.

Check for 12V between the choke hot wire and ground. It should be there.

Check for 12V between the choke ground terminal and ground. It should NOT be there.

If you have a measurable voltage between the choke ground wire and ground, then your ground is no good. I can't see where the ground wire is going, but it should go to a good ground on the block. You may wish to check for continuity between this terminal and ground as the first thing you check.

- Eric

DLaz70OLDS98

I would bet that you have your carb and alternator wires mixed up at the sending unit. Try switching them and see what you get.

MDchanic

No. The two "outside" parallel contacts go to either side of a switch.
They have no polarity.

The "middle" contact is for the oil light and makes contact with ground when the pressure is low.

- Eric

DLaz70OLDS98

I actually had an identical problem and when changed the 2 wires it magicaly worked. That was also the ONLY thing I changed. I didnt think it would have mattered what side of the switch I wired the choke and alternator to but IN MY CASE apprently it did.

joe_padavano

If you are using the PS 127 switch, the two outside terminals are simply the two terminals of a normally open switch that closes with oil pressure. It doesn't matter which wire goes to which. The center terminal is the OIL light on-off and it is also normally open and closes to ground with oil pressure.

As a simple test, remove the connector from the switch and connect an ohmmeter to the two outside terminals. You should get infinite resistance (as in, an open switch). Start the engine and you should get zero resistance (closed switch). If that works, the switch is working and you need to look at the wiring. From your pictures, I really can't see what's going on. I have no idea what the yellow wire is. The red wire from the + terminal on the choke coil needs to go to one of the outside terminals on the switch. The red wire from the alternator BATT terminal goes to the other outside terminal on the switch. I don't see a fuse, but I'd put one in for safety.

Also, verify with the ohmmeter that you have a good ground with the black wire going to the choke coil. Right now you have the black wire going to the carb body, which is insulated from the intake by gaskets and a plastic spacer. Yeah, the carb studs SHOULD provide a ground path, but there may be corrosion in the threads in the intake.

johnjuniper

Joe,
This electric choke using the oil pressure switch solution looked elegant, so I ordered a PS64 oil sending unit from Summit. When the Intermotor PS64 switch arrived, I could find no path to ground from any of the switch terminals. Turns out, the three terminals are wired as a single pole, double throw switch, no path to ground. This is useless for me, as the choke has only one terminal for power.


My have to opt for the relay solution.

Fun71

I think you read something wrong - the switch has no path to ground. It's just a switch that makes or breaks contact between the various terminals.

If your electric choke coil has only one terminal then it is designed to ground through the carb housing - just make sure there is no gasket between the choke cover and the housing.

joe_padavano

Unless Standard has changed the design of this switch, which would make it no longer compatible with it's original application (Chevy Vega), the center terminal should be grounded to the threaded body with no oil pressure and open when there is oil pressure. This is the terminal that operates the OIL light.

The two outside terminals are not connected to the center switch in any way. They are simply the terminals of a switch that is open with no oil pressure and closed with oil pressure. These are the terminals that are used to control the choke. Put power on one of the terminals, run the other to the + terminal of the choke. That's all there is to it.

If you are getting different connectivity on the terminals on your switch, it may be defective.

Mochi

Thanks for this Joe, do you know if the PS98 will fit? My local parts store doesn't cary the PS64

helm42

Thanks Joe and to everyone for this thread. Thanks Tom442 for the NAPA number OP6610, it's what I used on my 1970 Cutlass S.

This setup works great and well worth the extra steps to do it right!

coppercutlass

Short of sounding like an idiot what if you wanted to wire it to be on its own cuircut ? Im running a mechanical oil pressure gauge and dont want to T into it and use the sending unit to power up the choke. I like the second diagram Joe P. showed with the relay but i drag race my cutlass and tossing a belt is a possibility which it has happened so i would like to avoid the possibility of running into that issue. I run a switch to my dist from the power junction block on the fire wall with an inline fuse (kill switch/ anti theft ) . Would it be ok if i did this for the choke ? I know that juntion is always hot 12v . If i had a stock aplication i would do it the way it was written which is easy and straight forward but i have a few unique situations i guess i dont feel like messing with. I also have a junction for my quick release starter wiring harness to disconnect the main battery cable with ease ., so i could use an eyelet connector and wire it there too .


(edit) Im am stupid lol. A little more digging into the thread and the first way Joe P. mentioned is they im gonna go donw know why i was confused but after looking and some of the install pics the diagram explained itself even more . Looks like thats the easiest way for me. But could it still be done the way i wanted to ?

Macadoo

T-ing into the sending unit is kind of a pain but I thought it was the best way and has worked well for me. I think the main concern with running a dedicated circuit is having the choke heat up without the motor actually running.
You lost me with throwing a belt. Wouldn't you have to stop and replace it anyway?

coppercutlass

At high rpms belts become rubber bands the slightests misalignment will shoot them off the pulleys. I think I finally have that situation in check. But I have to consider it as a possibility. Not a street situation mainly something that happens at the track usually in the burnout box. If I toss a belt during a burn out then the choke closes and I get laughed at lol for breaking down., that's if I wired it as part of the alternators wiring circuit and that situations hapened. The the way I would do it if I did it on its own circuit would be to put the choke switch next to the dist. Switch can't forget them when they are next to each other.

MDchanic

Then just install an override switch, to use only when you are racing.

- Eric

oldcutlass

Copper, just run a keyed 12v wire to it and be done with it.

joe_padavano

Sounds like you figured out that the tee in the oil pressure line really is not difficult, but as for the second method and throwing the belt, unless you measure your quarter mile times with an hourglass, there is no way that the coil will cool off enough in the 12-14 seconds of a run to cause the choke to close.

coppercutlass

Yes joe thanks I'm gonna do the sending unit method as I finally got a good mental picture from the picture provided in this thread.

coppercutlass

Ok so it looks like I'm wiring from the alt. And I'm getting ready to do this tommorow as I just got my carb back from the shop. What is the correct oil psi switch. I'm not running an electric gauge fwiw. So if I understant correct. Wire from the alt. Wit an inline fuse to the sended and one from the sender to the coil and that's it correct ?

joe_padavano

From the first post in this thread:



There is only one oil pressure switch, the PS127. (Edit: Updated part number) It closes at 4 psi.

coppercutlass

Thank you. I just had to double check to make sure i fully understood how it was wired up seems easy enough thank you.

kitfoxdave

Joe, just some feedback on this choke set up. First things first... THANKS for a great way to do this! It is fantastic with the headlight connector (looks on purpose!) I bought 2 supposed PS64 switches (label on the box) and one had "Standard" markings on the packaging. I had to move the wires on the connector to the configuration (Middle lug forward) Left lug Generator, right lug to choke. Prior to that change, the generator light would not go off. There is some connectivity in these switches between the middle lug and the right lug in the no pressure condition! I hope this helps someone else...

joe_padavano

Thanks for the feedback. The last time I bought a PS64 was in 2010 when I put the E-brock carb on my 62. That one worked the way I wrote it up originally. I'll have to get another now and see if they've made some sort of design change.

Macadoo

I installed a PS64 on an Edelbrock 3711 just last summer. Following these instructions exactly, it performs as expected. Thanks Joe

coppercutlass

Yeah I forgot to mention my choke worked out perfect., got my switch from napa. I actually got asked 3 times at one cruise night what the hell it was for .

kitfoxdave

The PS64 that is in my car is from NAPA, the other is a "Standard" brand PS 64 that I bought on-line... As long as you wire them per Joe's instructions, and orient the lugs on the connector as shown in the picture in post #45 you will be OK. Again, this is a fantastic idea, and with all the input, has refined it nicely! Thanks to Joe and all the others that contributed to this!

JJSCUTLASS

Joe,

About ready to attempt this set-up also and i was wondering if i really need to hook up the Oil pressure wire to the PS64? I have a mechanical gauge and was just going to put the Tee in for that and run the 2 wires for the choke.

Thanks Jason

Macadoo

I'm not sure it's required but I think most do it because "it's there". I did, anyway.

JJSCUTLASS

Yeah, i was just wondering if that needed to be hooked up to complete some kinda circuit.
My oil pressure wire which is nice and wrapped up and tucked away has a big old rubber cap that sealed over the top of the old single pole Oil Switch. Didn't really want to cut it off! I figured i be fine not using that, but ya never know!!

Thanks Jason

joe_padavano

I owe you all an apology. Either my memory had become completely shot or the Standard Motor Products has changed the PS64 switch internal connections. The short answer is that the correct part number is PS127. This switch looks exactly like the PS64, but is wired as I described in the original post - center terminal operates the OIL light and the two outside terminals operate the choke. The interchange part numbers are as follows:

Standard Motor Products PS127
NAPA ECHLIN OP6618
Airtex 1S6552
BWD S369

Also, for those who want a factory-looking installation, Standard sells a three-terminal connector under P/N S956

Now for the long story. Thirty years ago, I wired the electric choke on my 71 442 using the PS64 switch, exactly as I described above. It worked exactly as described, for as long as I owned that car (it went away in the first divorce). Five years ago, when I added the E-brock carb to my 62, I used a PS64 as described in the first post. It's worked fine for five years, despite other posts in this thread by folks who've had problems.

Last week, I did some work on my 62 to repair a number of small problems. In doing that, I removed the dash cluster and cleaned the harness connector and pins on the printed circuit. I also replaced a number of broken holders for the 194 bulbs in the dash. Once I put it all back together, the OIL and GEN lights were on with the key off.

After a little troubleshooting, I determined that the wire to the OIL light from the sender was hot. Obviously this was a problem, which I quickly traced to the fact that the PS64 sender was allowing power from the BATT terminal on the alternator to the OIL light wire. Apparently, the OIL light on my dash had not been working previously (two wrongs do sometimes make a right), and once I fixed that, it uncovered the problem with the PS64 switch. After a short internet search, I discovered that the current iteration of the PS64 is actually a SPDT switch. The center terminal is common and is normally closed to one of the side terminals and normally open to the other. This switches when there is oil pressure. If you don't have an OIL light, this still works fine, but if you do, you need to use the PS127 sender. I've just purchased a PS127 (actually, the NAPA equivalent) and it is wired as I described in the first post. I have updated the information in the first post of this thread to reflect the correct part number. I apologize sincerely to anyone who was confused by this.

RetroRanger

I liked this idea too I purchased a ps127 standard oil pressure switch and wired it to my shiny new e choke on my shiny new Qjet (ok rebuilt but still shiny)....2 days later i goto start my cut and the battery is dead ! Using octanias logic of its probably the last thing you worked on i checked both side terminals of the ps127 (not the middle terminal) both show 12v w the car off meaning its shorted across the terminals w no oil pressure.

did i get a bad PS127 ? i cant find any terminal configuration on the net or at least at on stds website.

Macadoo

Hey Retro, I used the 127 with no problems. Sounds like a bad switch to me.

cfair

In case this hadn't been said, the 3 lead molded plastic connector is the same one used in headlights.

Auveco sells these molded connectors and virtually all other you might need to restore a classic olds with factory looking connectors.

Use a tiny flat blade screwdriver to bend the packard electrical connector closed and the wires drop right out. Solder in new wire leads and you're in business.

joe_padavano

Post #43 in 2014, actually.

cfair

Sorry for the repeat.

adis

Swapped in a RPM manifold, so I need to do this mod. I've confused the stock wiring and can't remember what's what (actually the pigtails have been hanging there unused for decades.) I've got a dark green wire with a square single connector, and a dark blue wire with a round single connector. I found a wiring diagram online for a '71 cutlass that depicts a dk green wire for the Engine Temp Switch and a dk blue with white stripe for the engine oil pressure switch. Can anyone confirm that this is correct for a '72 cutlass?

EDIT: Found the '72 wiring diagram as a stickie in Electrical:
https://classicoldsmobile.com/forums...g-diagram.html
Yes: blue is oil, green coolant