1968 Plymouth GTX

Show off your work! Anything from final results to full start-to-finish project journals.

User avatar

Board Moderator
Posts: 7162
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Fri Jul 20, 2018 7:05 pm
I reinstalled the fenders and aligned them with shims to the cowl surface and doors. My goal is to know what shims are needed and where so that on reassembly I am not putting freshly painted parts on and off the care repeatedly.

Removed the steering column by unbolting this plate:
Steering Column Base.JPG

Then removing these nuts and washers (not sure what that ground wire was hooked to):
Steering Column Dash Mounts.JPG


Removed the dash which has a bolt on each side it slides over as seen here, plus smaller bolts across the top along where the windshield runs.
Dash Assembly Mount Driver Side.JPG


The whole dash assembly will then tip forward for easy access to the wiring connections:
Gauge Cluster Wiring.JPG


This gave me access to the heater box which is held in place by the brace attaching to the body and 3 bolts that extend into the engine compartment area:
Heater Box.JPG


Removing the box gave me access to the firewall insulation.
Firewall Insulation.JPG


The thing that always amazes me about these older cars is how often the wiring is messed with. The picture above shows the back of the gauge assembly and you will see there are no wires attached to the panel light switch. Instead they had a homemade jumper wire connecting the leads together. Did the same thing with the ballast wires:
Wiring Balast bypass.JPG


Found numerous places where wires in the harness are cut and just left uncovered:
Wiring Issue Headlight Circuit.JPG


This connector only had 1 strand of wire left holding it together:
Wiring Headlight Lead Connection Bad.JPG
1968 Coronet R/T


ACTS 16:31



Top Contributor
Posts: 4040
Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
Country:
USA
PostPosted: Sat Jul 21, 2018 9:17 am
I have gotten to the point where I just plan on buying new Harnesses when dealing with these old cars. especially if its been Hacked up or I am into it as deep as you are.
New Original type type Harnesses are not all that expensive really when you start thinking about piece of mind that 50 year old harness is hard and brittle and the insulation cracks when its moved leading to shorts worst case scenario and or a new crack in the insulation to allow moisture under the insulation to allow the wire to corrode increasing the wires resistance.

Ever seen a car burn up on side of road ? Most often its from incorrect armature radio installations then theirs times The Harness shorts out for one reason or another.

Older cars like that also have an AMP Gauge you want to replace the circuit with a VOLT gauge. Amp gauges are very dangerous really, Company's like American auto wire sell kits that have already been modified.

I had a nice 62 Hawk restored with its original harness dam near burn to the Ground driving home after a car show once. The wire from the original Amp gauge shorted out took the whole harness with it. I was lucky didn't loose the whole car.
I got it pulled over quick popped the hood and disconnected the Battery I was very lucky!!! it could have just as easily burned to the ground.
Last edited by Doright on Sat Jul 21, 2018 9:28 am, edited 1 time in total.
Dennis Barnett
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

User avatar

Board Moderator
Posts: 7162
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Sat Jul 21, 2018 9:26 am
Yeah, I figured this wiring looked pretty beat up. When I did the Coronet the wiring was actually in very good condition. I normally lay the harnesses out on a table and inspect them closely for brittle insulation, cracks and connector issues. Had a 1968 Mustang once with a wiring issue. There were no cracks or obvious shorts but I couldn't get an continuity with the ohm meter. Turned out to be a corrosion problem within the wire casing. It just looked a little enlarged and was very soft to touch. When I cut it open there was nothing but powder left of the wire.
1968 Coronet R/T


ACTS 16:31



Top Contributor
Posts: 4040
Joined: Tue Sep 16, 2008 1:17 pm
Location: Pahrump NV.
Country:
USA
PostPosted: Sat Jul 21, 2018 10:03 am
My 73 Plymouth's Dash wire harness doesn't look all that bad either but the engine harness is trash I am replacing the under Dash harness just for safety sake $600 and the engine harness because its Trash and its cheap like $160-170 bucks not worth the effort to repair.

My 70 Pontiac the under dash harness has been butchered and the engine harness is just a brittle mess including the head light Light harness I am replacing all 3 on it. Now they want a premium for this cars Dash harnesses all said This cars wiring gonna cost me a Grand plus I think they wanted $1500 for all of it last I checked but I was having it up graded with a engine Tach and 4 speed harness stuff to be a Trans am clone.

On both cars I can handle repairing and cleaning the rear harnesses unless there brittle and then they are cheaper than the engine or the headlight.

There is just so much work cleaning and painting re-plating anodizing to put a old tore up harness in a restoration just doesn't make much sense to skimp on it.
Anything less than an original harness looks like Fido's rectum in my opinion unless your doing a Custom with hidden wires.


http://www.evanswiring.com/catalog.htm

https://www.americanautowire.com/produc ... storation/

http://www.wiringharness.com/
These guys make Chrysler harness for Year one

Also there are some places that you can send them your old harness and they will restore it with new wire and new metal connectors reusing your Plastic stuff. food for thought.
Dennis Barnett
A&P Mechanic, FCC General radio Telephone Operator
Line Maintenance A&P Mechanic and MOC Tech specialist.

User avatar

Board Moderator
Posts: 7162
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Sat Aug 11, 2018 8:12 pm
Looking at the heater box.
The first indication of trouble is that the control cables on the right side are not hooked to anything.
Heater Box.JPG


With the box out of the car we can see now where the water was getting in. The round seal is for the passenger side vent intake and was clearly not sealing to the cowl panel very well.
Vent Seal Passenger Side.JPG


Here we can see why the passenger side cables were not hooked up.
Heater Box 2.JPG

Notice that the Right side control lever is broken off completely.

A picture of what should be there:
Heater Box.jpg


Here's the firewall side of the unit:
Heater Box Backside.JPG


Pulled the cover off and looked at the squirrel cage:
Heater Box Cover Removed.JPG


Here's the diverter door that isn't working:
Heater Box Diverter.JPG


The foam seals are all deteriorated and turn to powder when you touch them. I will test the motor and look the entire unit over before making a decision on whether to rebuild or replace. Right now I am leaning toward rebuilding it.
1968 Coronet R/T


ACTS 16:31

User avatar

Fully Engaged
Posts: 178
Joined: Fri Apr 22, 2016 8:17 am
Location: Detroit
Country:
USA
PostPosted: Sun Aug 12, 2018 3:54 am
What's your plan for the car, back to conquers correct, or make it a hot rod it?

User avatar

Board Moderator
Posts: 7162
Joined: Fri Oct 20, 2006 12:40 pm
Location: ARIZONA
PostPosted: Sun Aug 12, 2018 10:07 pm
I will restore this one however I have been considering upgrading suspension and going with fuel injection.
Not sure yet.
1968 Coronet R/T


ACTS 16:31
Previous

Return to Completed & In Progress Member Projects

Who is online

Users browsing this forum: No registered users and 2 guests