Where is the bulkhead and engine wire harness connector located?

Leo2+2 · Guru

Where is the bulkhead and engine wire harness connector located?

67Poncho · Uber Guru

Leo, the bulkhead is the fuse box... You have 2 connectors that plug into it from the engine side.. With the key on, did you ground the oil light wire to see if it works?

Leo2+2 · Guru

No, not yet. I just played around the oil pressure switch but no luck. I didn't even check if the bulb is burnt or lose.

Leo2+2 · Guru

67Poncho wrote:
Leo, the bulkhead is the fuse box... You have 2 connectors that plug into it from the engine side.. With the key on, did you ground the oil light wire to see if it works?

I checked but can't find a dark blue wire.

Today I took the car in for an oil change and asked my mechanic. He took a peak, tested some wires but no light came on. He said it's most likely a burnt bulb but we both had no time to try to get it out.

Does anyone know how to access the oil pressure light? Do you need to remove the dashboard padding and if so, what's the best way?

Cheers.

67Poncho · Uber Guru

I have 20 of these here... Put your arm up behind the dash working from underneath.... AND, like said previously... You have to GROUND that wire... Did you do that?

Leo2+2 · Guru

No, I didn't do that because I don't know which is the right wire.

Where the OIL lamp is, there appears to be a harness with a bunch of wires, about 10 of them. Is that where I'm supposed to look?

4SPEED427 · A Poncho Legend!

I believe what Vince is saying is to remove the blue wire from the oil sending unit at the back of the engine, ground it with the key on and see if the oil light in the dash comes on. When you do this, if the light comes on, you are confirming that the circuit is good and the bulb is good.

Leo2+2 · Guru

Carl Stevenson wrote:
I believe what Vince is saying is to remove the blue wire from the oil sending unit at the back of the engine, ground it with the key on and see if the oil light in the dash comes on. When you do this, if the light comes on, you are confirming that the circuit is good and the bulb is good.

The wire was removed from the unit behind the engine and grounded; the light did not come on [with the key on.]

67Poncho wrote:

I have 20 of these here... Put your arm up behind the dash working from underneath.... AND, like said previously... You have to GROUND that wire... Did you do that?

This photo as from below the dash looking up. The yellow circle is where the OIL LAMP is located and for sure one of those wires is the one you're mentioning. Do I grab and pull out the whole unit as to unplug it, and then which is the wire I should unplug. another problem: I AM COLORBLIND.

Thanks

hawkeye5766 · Canadian Poncho Superstar!

By the look of the wiring diagram in your fist post, the oil light is the dark blue wire with the white stripe. There will be a tab on the side or ends of the plug that needs pushed in to remove from cluster.Squeeze the plug on both sides and carefully wiggle back and forth to remove.

-- Edited by hawkeye5766 on Monday 3rd of November 2014 09:45:49 PM

Leo2+2 · Guru

LOL I got a stiff neck and my hand barely fits. I think I need a drone to get that unit out! I need to recoup and try again tomorrow. Will let you guys know.

67Poncho · Uber Guru

Leo2+2 wrote:
LOL I got a stiff neck and my hand barely fits. I think I need a drone to get that unit out! I need to recoup and try again tomorrow. Will let you guys know.

That's correct Carl! I forget that I know what I am saying but others may not have the background I do... Sorry for that... That being said, sometimes the twist in sockets com loose and a re-twist is all that's needed... Or possible a blown bulb... Remove and try another!

Leo2+2 · Guru

Thank you, Vince.

The plug seems to be stuck and hard to remove, also because the way my hand extends and I don't have an ideal grip on it. My last chance is my 12-year-old with his small hand ... but he broke his arm and is in a cast (go-karting accident, likes racing like his dad!)

Another stupid question and forgive my lack of knowledge ... where is the lamp located so that I can try wiggling it or removing it? I hope it's not behind that plug...

seventy2plus2 · Canadian Poncho Superstar!

You can see a lamp socket immediately below your yellow circle. It takes 1/4 turn counter clockwise to remove it. The lamp for the oil pressure light will be directly behind the indicator.

Leo2+2 · Guru

I removed the bulb and switched it with the BRAKE one. None of them work. Then I switched it with the TEMP light, again none work. So I put the bulbs back in their original places so that the BRAKE and TEMP work. I guess there's something wrong with the bulb or socket but there's got to be something else wrong otherwise when I switched the bulbs around, OIL should have gone on.

What next? I'm not very handy at this so very advanced instructions I may not understand.

Cheers,

LEO

hawkeye5766 · Canadian Poncho Superstar!

Sometimes it is easyer to unscrew the whole dash cluster and pull it out a few inches if there's enough slack in the wiring. That way you don't have to lay upside down. Not familiar with your cluster but someone should know if doable.

4SPEED427 · A Poncho Legend!

Usually you have to undo the speedometer cable to pull it out but otherwise I am guessing you will be able to, yes.

I don't know about 67 but on 66 it's a number of screws to remove the dash pad but it might be worth it in this case. With the pad off, you're staring right at all the stuff at the back of the cluster.

Leo2+2 · Guru

Carl Stevenson wrote:
Usually you have to undo the speedometer cable to pull it out but otherwise I am guessing you will be able to, yes.

I don't know about 67 but on 66 it's a number of screws to remove the dash pad but it might be worth it in this case. With the pad off, you're staring right at all the stuff at the back of the cluster.

Was out of town for a couple of days and just got back. Cranked up the engine and went to fuel up for the winter since $119.4. Got to catch up on a few things; I think I know exactly which screws you are talking about and definitely worth a shot.

Leo2+2 · Guru

I FOUND THE PROBLEM. I unplugged the wire from the switch unit behind the engine, grounded it and BINGO! OIL light went on. Now I gotta find a new switch to replace.

67Poncho · Uber Guru

Leo2+2 wrote:
I FOUND THE PROBLEM. I unplugged the wire from the switch unit behind the engine, grounded it and BINGO! OIL light went on. Now I gotta find a new switch to replace.

(lololol) I asked you that on November 1st... Your just doing it now?.... Better late than never... biggrin biggrin biggrin But seriously, glad you found it.... That switch was used for decades... Shouldn't and won't be an issue... I am sure you can still get them new if need be...

-- Edited by 67Poncho on Sunday 16th of November 2014 10:48:10 PM

4SPEED427 · A Poncho Legend!

Pretty sure it's 3815936. I've sold lots of those over the years.

seventy2plus2 · Canadian Poncho Superstar!

Carl Stevenson wrote:
Pretty sure it's 3815936. I've sold lots of those over the years.

That part # looks to be good on ebay. I imagine any GM dealership can get it for you.

4SPEED427 · A Poncho Legend!

Yup, at least it used to be readily available from GM. I can check for him tomorrow if he checks in here and wants to know. It was cheap too as I recall.

Leo2+2 · Guru

67Poncho wrote:

(lololol) I asked you that on November 1st... Your just doing it now?.... Better late than never... But seriously, glad you found it.... That switch was used for decades... Shouldn't and won't be an issue... I am sure you can still get them new if need be...

-- Edited by 67Poncho on Sunday 16th of November 2014 10:48:10 PM

You must be having a field day!!! As I said before, I'm not that handy ... and likely one of the least knowledgeable members of CP when it comes to electronics... but with the passion I have for classic cars, I am trying and don't give up easily. I can laugh, no problem....

All joking aside, it seems like it's going to be tough to unscrew it off because of its proximity to the distributor and several wires and stuff that prevent my hand from fitting. Any hints from experience?

Thanks, Leo

67Poncho · Uber Guru

Leo2+2 wrote:
You must be having a field day!!! As I said before, I'm not that handy ... and likely one of the least knowledgeable members of CP when it comes to electronics... but with the passion I have for classic cars, I am trying and don't give up easily. I can laugh, no problem....

All joking aside, it seems like it's going to be tough to unscrew it off because of its proximity to the distributor and several wires and stuff that prevent my hand from fitting. Any hints from experience?
Thanks, Leo

Not at all, Leo... laughing with you, not at you.... Yes, car electronics does come easier to me.. my 18 years with GM, I was the wiring, drivability guy... My first EFI conversion was done back in '91 on my '70 Parisienne... EFI in the fullsize GM trucks was only 4 years old... I believe you need a 1 1/16" deep socket with an extension... That should do the trick for you... Breath easy, no finger pointing nor full cage ribbing intended.... We're all here to help.. smile

Leo2+2 · Guru

Thanks Vince. I'll certainly give it a try tonight or tomorrow night. Since the switch measures oil pressure, should I expect dripping as I pull it out? Or is it minimal drips?