REMOVING THE DASHBOARD FROM A 1970 CUTLASS SUPREME CONVERTIBLE, PART II of II

When we last left off (i.e., diminishing light and cold hands meant it was time to stop), we had the dashboard undressed and ready for the final steps for removal.  We’re back to work.  Have the usual tools at the ready, plus a 9/16” socket on a 1/2” ratchet.

For both the weather and protection, I wear a pair of cheap, thin cotton gloves.  They help just enough to keep knuckles from getting scraped.  When operating screwdrivers and the like I take them off for better grip.

Not as many photographs this time around because most of this work is done blind behind the dash.  Instead I’ll use pictures from the service manual, which may or may not be copyrighted.  We’ll find out when I get the cease and desist letter.  I’ll use numbers to match the text descriptions with the locations on the diagrams.

1)  Remove all the light bulbs as is appropriate.  Here’s a list of what needs to come out.  I don’t think this changes much with different option packages:

• Footwell (2, 1 far left and 1 far right, orange/white wires)
• Accessory Panel Floodlights (4, just below the instrument panel, 2 each below the idiot lights and the clock, gray and gray wires)
• Ashtray (1, right side of ashtray near the top, accessed from behind, don’t remember wire color)
• Headlight Switch (1, left side, accessed from behind and above the pull knob, don’t remember wire color)
• Glove Box (it is already dangling, just make sure the bulb is removed so you don’t break it, orange and white)

The courtesy light above the radio can stay.  That’s attached to the dash panel, though you will need to remove the wiring harness later.

Let’s talk a bit about the headlight switch bulb.  You know why you never see that thing working on a 1970-72 Cutlass?  It’s fucking impossible to replace.  There is about 0.0002” of clearance between the headlight switch and the LH A/C duct. Every Cutlass A-body, A/C or not, has these vents.  Why they designed the bulb to be impossible to get at, I have no idea.  And that bulb fit in there SNUG.  This will be the most annoying part of the job, hands down.  I ended up leaving this bulb for the very end.

No picture here, as these are pretty easy to figure out.

2)  Remove all the wiring connectors.  You’ve already done half of these when you removed the instruments and radio.  Here’s what’s left, from left to right.  Item in brackets are not on my car, but may be on yours if you have more options than I do:

• Headlamp Switch (one 5-wire connector and one 2-wire connector)
• Wiper Switch (3-wire connector)
• [2^nd Accessory]
• Convertible Top Switch (4-wire connector)
• A/C or Heater Control (there’s something like 3-4 individual harnesses on the thing, probably 5 if you have a rear window defogger which I am thinking wasn’t available on the convertible; they’re all different shapes so just tie them together and label them “A/C Control”)
• Cigar Lighter (wait, this is 2013:  the 12-volt accessory power terminal, one wire, round connector)*
• Courtesy Light (2 connectors, one a 2-wire and second a one-wire)
• [4^th Accessory – what the heck would go this far from the driver?]

All of these pop off pretty easily.  Use the flagging tape to bundle them together and mark where they go.  The harness is put together so that it’s impossible to hook the wrong thing up, but better safe than sorry.  You don’t want to be on a date, turn the windshield wipers on for rain, and have the top go down.  Awkward.  Especially if your date is wearing white.  The only one you might possibly screw up is the A/C Control, so if you have anxiety issues label each one separately.

Again, no pictures.  The picture below, Fig. 12AA-30, shows most of them.

3)  Remove wiring harness clamp screws.  The service manual says there are five of them.  I found four.  This step is easier than it seems.  Two of the screws are uber-easy.  They are located at the top of the instrument cluster, left (H2) and right (H3).  You can see where the plastic is molded to accommodate the screw socket.  Or shaft.  Or hole.  Whatever.  You’ll find one just to the left of the wiper feed (H1).  The last screw is actually a ground wire just above the A/C control and below the clock; it screws into the RH flood light fixture (H4).  What is supposed to be (H5) looks like it just clips to the back of the ashtray somehow.  I don’t know for sure because on my car it was loose.  If you know where it goes, send me a message so I can update this.

Location of the wiring harness screws/attachments, 1970 Cutlass Supreme (and pretty much every 1970 A-body)

To make it easier to get these out, I used a 1/4” socket attached to a short extension.  It’s hard to work a ratchet in the tight spaces and the screwdriver attachment is hard to fit behind the dash.  I’d also suggest using a 12-point socket instead of 6.  I normally use 6-point, but the 12-point gives you a greater margin of error.  These screws shouldn’t be in super-tight, so you won’t need to worry about screwing up the heads.  Pun intended.

4)  Remove A/C Control unit.  Don’t worry about removing all the vacuum hoses.  Leave those on for now.  To get the dash out, you just need to move this.  There are three screws:  One left lower, one top, one right lower.  They’re pretty easy to see from behind.

A/C – Heater Control screw location, 1970 GM A-body.

5)  Remove dash pad nuts.  There are supposed to be 4 of these:  1 to the outside of each A/C vent (D1 and D4), and 2 above the glove box opening, near each corner of the glove box (D2 and D3).  When I went to remove my dash, I had only 3 nuts.  The stud on the LH side was barren.  Allan R from ClassicOldsmobile.com tells me that this stud has only a pressure fitting on it.  That makes sense; it would be really hard to get a tool up there to put on even a self-threading nut with the ductwork in the way.  Said pressure fitting is missing from mine.  Guess it’s time to place an order at my friendly neighborhood restoration parts place.  I need to order some 1/4″ screws for the lower A/C vents anyway.  Assuming the mounting holes aren’t stripped.

Location of dash pad nuts, 1970 Cutlass Supreme (and pretty much any 1970-72 Olds A-body)

BTW, you need to use a deep shoulder 3/8” socket from a 1/4″ ratchet set on these nuts.   Use the short ratchet extension as a poor man’s screwdriver.

D4 is lower on the dash pad than the picture makes it appear.  It’s a couple inches from the bottom, actually.

6) Remove control panel nuts.  These are all along the bottom, evenly spaced to make it easy to find them.  Look between the wiper switch and headlamp switch (C1), left and right lower corners of the heater control cutout (C2 and C3), and to the right of the radio cutout, below the courtesy light (c4).

Location of control panel nuts, 1970 Cutlass Supreme (and pretty much every 1970-72 Olds A-body)

7)  Deal with the gearshift. Technically speaking, the dashboard is unattached and should come right off.  But not so fast.  If you have a column-mounted gearshift, you have to get around it.  There’s two ways you can go about this.  First is to follow the shop manual.  To do this, you’ll remove the kick panel behind the pedals; this is the black plastic thing that holds the carpeting in place and keeps crap from the bottom of your shoe from getting under the carpet.  Next, you loosen BUT DON’T REMOVE the five bolts on the toe-pan cover.  Then you remove the two nuts that mount the steering column to the inner dash.

That’s too much work.  You know what else works?  Just loosen BUT DON’T REMOVE the two nuts on the steering column.  This will drop the column about 1/2″.  Activate the parking brake.  Put the key in the ignition, turn the car to on.  (You disconnected the battery, right Mr. Bungle?)  Shift into neutral.  Presto. You’ll clear the gearshift.  Just make sure to put the car back into park and turn the key off when done.  I snugged up the two nuts on the steering column as well.

FYI, there may be shims on the steering column mounting bolts that will fall off when you loosen the nuts.  Be forewarned so it doesn’t hit you in the eye.

8)  Remove dashboard.  Just lift the dashboard over and out.  NO!!!!!  The dashboard won’t come out!  The shop manual says it should.  Something’s holding it up.  What could it be?  NO, WAIT!   I have… the Mystery Screw.  It’s not in the shop manual.  But it’s on my car.  Why is it there?  Notice that my control panel has a crack in it.  I don’t know how it got there.  The screw is a 1/4″ screw that looks like a factory screw.  I have a few theories:

1. The control panel was broken in the factory and didn’t quite mount flush as a result.  The assembly line worker did what I would have done; drilled a hole and screwed it down.  No one’s gonna see it, and there weren’t any lemon laws in 1969 when the car was built.
2. A previous owner broke the control panel while messing around behind the dash, and screwed the panel to the support brace to hold it in place because he/she was getting annoyed by rattling.
3. Sugar Bear wanted to fuck with my head and one night in 2002 he snuck into the garage at 3am and did the deed.

The Mystery Screw

Once the Mystery Screw is removed, the dashboard comes right out.  Now look at all the room you have to work on that heater core.  If anyone else out there has a Mystery Screw, let me know.

Looks like the front window defroster ducts come out and there’s hardly anything else in the way

In an effort to make locating all of the blind screws and nuts a bit easier, here are pictures of the left and right side of the dashboard from behind.  All of the dash pad nuts, control panel nuts, and wiring harness screw locations are marked.  This should help you find them by feel, if nothing else.  I’ve also marked the location of the A/C – heater control module screw locations with red arrows.

View of the LH side of a 1970-72 Oldmobile A-body dashboard from behind, showing location of attachment points.

View of the RH side of a 1970-72 Oldsmobile A-body dashboard from behind, showing location of attachment points.

Before I go, I said I was going to talk about getting out that damned headlight switch lamp.  Here’s what I did:  Once I got the dashboard clear of the steering column, I had enough room to get behind it and remove the LH A/C vent.  There’s two 1/4” screws holding it on.  Once it’s out of the way, you’ve got some room to get at the bulb socket.  Turn the bulb so the locking tabs are released.  Using an English screwdriver, gently tap on the lip of the bulb fixture.  A few taps should move it enough that you can pull it out of the cylinder.  Sorry for the lack of a picture.  I was mad at the thing.

A few notes for when I do reassembly:

• Use tune-up grease on the headlight switch lamp and the ashtray lamp.  Wishful thinking says that will make them easier to remove when the bulbs next burn out.  And you know the headlamp swtich bulb is going to be the first one to go after you put everything back together.
• Do not tighten the dashboard until you are sure you have the wiring harness properly snaked.  You’ll be pretty pissed if you find out you have to re-route the wires after you’ve tightened up all the nuts, scraping your knuckles in the process.  It should be OK to screw down H1, H2, and H3 before you re-attach the dash pad and control panel nuts.
• Follow a checklist from left to right when reconnecting the wires and lightbulbs.  If you used the flagging tape to label the wiring connectors and the lamps, do not pull the tape off until AFTER you’ve reconnected the part.  If you have a labeled wire left over you know you missed something.
• Once you’ve got all the wiring connectors hooked up and before you put the gauge clusters back on, feel free to hook up the battery and check that things work.  As long as you’ve got all the grounds hooked up you should be safe.

BTW, if you don’t count the time I spent dicking around, taking bathroom breaks, helping my neighbor get her car up the snowed-in driveway, looking for dropped tools, and messing with wiring connectors that didn’t need to be disconnected (there’s one for the A/C control that was installed just to trick me, I’m sure), this took about 3 hours.

*One of the most lasing legacies of cigarette smoking may well be the 12-volt accessory power terminal.  Until automakers replace it with USB ports.