Guss - 1970 Challenger

[Guss]

Hi Gals and Guys !
So... This is a 1970 Challenger I just bought. These were some of the pictures from the seller.

I bought this car without seeing it for real.
I just saw it on a Norwegian website (I'm in southern-french-speaking-part Belgium so about 1000 miles away from the car location), called the guy, made a videocall to see the car that way, discussed the price a bit, and the deal was sealed.
Few weeks after I received the car here.

I discovered a few unsaid things, the usual stuff when buying without a personnal inspection.... But overall the seller has been honest.
Happy with the purchase.

Now to describe the car :
From factory she had a 383 2bbl with an auto on the column. Factory B7 blue, black interior, black vynil top.
Not a rare car what so ever, but good to know she was a big block and B7 from factory ! Checked the cowl stamped vin and it matches. Good !
Got the build sheet. That's cool too !

I did not know the engine code when I bought it... First thing I did was check that, and of course... it's a 1977 RV engine. Dang it.
I'm not going to cry. The price was right.

Obviously you can see some body work was done recently in Norway (rear quarter pannels), and eventhough I would not say it's a good job, I would not say it's a bad job either. I like butt welds, and there it's overlapped. But at least they did not warped the whole thing.
New front floors, new trunk floor.
New tank and sending unit as well. Other nice thing is that I have a seemingly complete Wilwood front disc kit (not fitted to the car, brand new) ! That's neat.
You E body enthousiasts will also pinpoint that the interior is somewhat incorrect. Dash pad, steering column/wheel and seats are from a 1972-4 E body.

You'll also see that the body pannels are all misaligned. You are starting to get the idea of this car... What I know she was before buying... A car that has been rougly and quickly repainted just prior to beeing sold. Which happenned to be in 2009 when the Norwegian guy bought it.
Pretty common. Lots of European buyer "get got" !

So I pulled the thickness tester and to my surprise, only discovered a few area's where the body filler really is thick. That's the best news so far !
Underneath the vynil, the roof seems to be quite OK except for the back glass corners, like often. very happy with the body pannels actually!

The trans linkage was so badly adjusted that she would NOT hold the Park position. Very dangerous since she does not have the parking brake cable fitted. One time she engaged the reverse just like that when idling, by herself ! Fortunatly I was behind the wheel and nothing bad happened.
Of course, re-adjusting this is the very first thing I did.

Enough spoken.
Here are a couple of pictures of the car in my dusty shed.

(note that lovely clean sink on the upper right side of the picture. the place used to be an old garage. The old man wasn't really into cleaning stuff but it plays a role in the general atmosphere of the place. Or maybe I'm just too lazy to repaint the shop and find excuses. That's very possible too.)

Now the work has started on the car. I'll get to that later.
One thing I can tell already : I want it more sober looking. I'm not really into that white top, white stripe and spoiler - look - unless it's from factory. Which it isn't ! (not even the right spoiler!)

I did a little cranking pressure test because I felt the engine "was speaking pretty loud" for an RV engine and here's what I got on all 8 : 190 PSI !
Pulled the borescope to check the pistons but they seem to be the original flat tops. Heads are 452's. So that's probably just a Camshaft. But the cylinder walls look very nice ! I'll take it !
She does not smoke one bit, the valve train look new... Nice !

My goal with this car is to have a good reliable driver. Not a perfect shiny car (at least for now). I have a Shiny car (the 1966 Pontiac 2 doors wagon you can see in my member intro) already. I'm worried of driving it if the conditions aren't right.
I want the opposite for this car. I want to live with it. Take it to work maybe. Somebody sits on the fender ? I won't get mad.

In other words, I want to enjoy the cr.... out of it. But to make it reliable I have a lot of work to do.

To end this post, wanted to say thanks again for having me on the Forum. I have had the car for now 3 weeks, and along my work on it, you don't know how many answers I've found on different threads up here already.
Long live to the forums.
I know some of you don't really like the idea that these cars aren't on the American soil and I understand that. If that can make you feel any better, few of these are really valuable ones, most of these are very well taken care of, some of these even go back to USA after some time (I know of a real Hemi cuda that was shipped back to USA!)

Cheers

 

[Juan Veldez]

Great introduction, thanks for that! Looks like overall you got a really good car. And I do not care if she's across the pond. Seems like she will be taken care of and that's all the matters. Cheers!

 

[mrmopar340]

Nice ride there. I'll bet you'll enjoy it greatly.

 

[marksmopars]

Beautiful car, thanks for sharing. Also, it is my understanding that the RV engines were a good platform to build from, tho I would lose the 2 barrel. Good luck

 

[Guss]

Thank you guys!
Amongst the things I like to do when I get a "new to me" old car is checking the electrical system. I'm always worried something might get hot and burn the car to the ground. You just never know with a 50+ year old car...

Beeing just out of a Pontiac restoration (that has a very simple - very logical electrical system), I found the '70 challenger diagrams on this Forum and started reading thread.

Long story short, I quickly learned about the "amp gauge system" on these mopars.
Checked the bulkhead connector and of course... My car was subject to that issue. Very much so.

This partly explains the low tension on the car. In fact with the key in "run" position, I could see the voltage dropping to 9.6v (and the battery is new and charged).
On the "under hood" side of things, the harness beeing in good and pretty original condition, I simply gave the car the "amp gauge bypass wire" treatment, running a 6mm²/10awg with a 35A fuse wire from the alternator to the starter relay.
Now I know that most of the current needed to charge the battery does not run through the dash anymore. Of course, that is only part of the solution.

I could see from down under, that the dash wiring had been butchered previously, and wanting to bypass the Amp gauge I just decided to pull the whole dash wiring harness.
It was a good decision. Really is not complicated to remove and working on the bench is so much more comfortable.

It also was a wise decision to bypass the amp gauge, because that little fella was very corroded. That clearly was a huge resistance in the system as well !
Note that purple wire that has NOTHING to do there (temp sending unit wire connected to the amp gauge ???). As said, it's good that check all this, because somebody has been here, and has done some very wrong things.

Is it even worth noting that the dash bezel is totaly distroyed ? Someone at some point decided to integrate newer styles of temp and oil pressure gauge. By integrate, I mean cutting the bezel with an axe or something similar.

But anyway. Such is life. I'll repair or change the bezel later in life.
Here's the full harness.

and this is all the unnecessary wire and cr.... that I removed from it.

With the wiring diagram in front of me, spend a full day fixing the harness. Soldering this, cutting that, insulating this, .... Checked absolutely all the connections and cleaned the contacts.
Bypassed the amp gauge at that point as well. Drilled the bulkhead to pass a plain 10awg wire (avoiding the stupid burned spade connector) to feed the vehicle. See the "MAD" website linked below.
To be honest it was a bit overwhelming at first, but bits by bits it became clear and in the end, it's really not that complicated.

Put everything back on the car. After a few little adjustments here and there (like cleaning the internals of the heater switch!), everything works ! All the lights, all the switches.
I now have all tail lights working correctly which was not the case before. (Had the change the neutral safety switch to have the reverse light, though).

I also have a working fuel level gauge!! That makes me very happy !
So cool to see all the lights coming up to life when opening the door ! (sorry for the quality of the pic)

The only thing I still need to adress is the wipers that don't go back to parking spot. Read somwhere that it could be caused by the switch not beeing grounded, but it is on my car.
I'll have to adress that.

Anyway, I'm happy I did that electrical work. I now know this car's electrical system much (MUCH) better. And I have gained a lot of confidence on the car itself.

To try and help others the way I did find some help :

Here's where I got the full wiring diagrams (those are the real black&white OEM ones from mopar)
Here's where I found colored versions of these diagrams. Unfortunatly they are a bit pixelized.
Here's the infamous bypass wire explanation for the charging system, click on "see page 2" at the bottom of the page to see the fix.

ATTENTION : If like me you have a 1970 challenger with a regular engine (not Hemi), you still HAVE TO USE THE HEMI DIAGRAM for the engine bay harness. There was a mistake in the OEM repair manual, the wiring diagram for "non hemi" engine is not correct at all (letters instead of numbers on the bulkhead connector).

Have a great day, all of you !
My next work will be the power steering box that leaks like crazy.

 

[terrywalker]

You are making good progress. Congratulations on getting the car. Enjoy.
Terry W.

 

[Cuda Hunter]

Sweet car!
Love reading along with your work updates.
Can you post the fender tag?
L code I assume? JH23L0B ?
B7 is one of the best colors!

 

[Challenger RTA]

Drilled the bulkhead to pass a plain 10awg wire (avoiding the stupid burned spade connector) to feed the vehicle.

Guss for the most part it sound like you know what you are doing. Below is a diagram showing the original wiring and dots show the charging and load paths. Did you drill out both bulkhead connectors 16 for the battery and 18 the load feed from the alternator? It feeds splice one from where all the loads are feed from. If wiring hasn't been altered. The other thing is to look at is the ignition connector under the steering column. Here again. 12R battery feed to sw and 12 BK feeds ACC side of fuse box. One last thing! If you did not inspect the battery feed A1 12R wire and alt load feed wire R 6 12 BK. Abandon them! Run new wires in place of them.

One word explains the wiring and connections. Inadequate! Read Description and follow the dots. The wiring is not heavy enough and the connection were not designed to carry that much amperage 1:RED wire 16 Battery power yellow dot to splice one feeds fuse block, 2:charge wire 18 black wire blue dots to splice one through amp meter to red wire blue dot 16 to battery, 3:ACC feed from splice 1 Red wire Q3_12R yellow dot to steering column. Black wire 12BK red dot to ACC side of fuse box.ch load. The round back alt has an output of 37 to 45 amps max and the wiring is designed for that.
When everything is in good shape.
View attachment 92025

Search the site.​

One Terminal Melted in Firewall Junction Block: If you didn't read it there is a few things there to read.​

Splice one.

I would think your are going to be doing a headlight relay circuit. Side note for reference. When doing the Alt bypass. Connecting to the alt feed to the starter post and or the starter relay. It is electrically the same as feeding the load from the alt. As long as there is a feed going to splice one some how. A new wire? Via connector 12 or 16 or both but fused. If the amp gauge wires are good. connecting them together would complete the circuit. Pick a path and fuse it.

 

[Guss]

Sweet car!
Love reading along with your work updates.
Can you post the fender tag?
L code I assume? JH23L0B ?
B7 is one of the best colors!

Hi!
Unfortunatly, no fender tag on the car. But I have the build sheet. And exactly, it is a JH23L0B built in may 1970 at the Hamtrack, MI facility.
You'll excuse the fact I don't really want to put the full vin number on the web, but here's the most interesting part of the build sheet I decoded.
As said before, nothing crazy. But indeed, love the fact that it's an original EB7 paint code car!

 

[Cuda Hunter]

That's great that you retain the broadcast sheet.
You can have a new fender tag made from the broadcast sheet.
Prize of a car for sure!

I'm curious, what Pontiac did you restore?

 

[Guss]

Guss for the most part it sound like you know what you are doing. Below is a diagram showing the original wiring and dots show the charging and load paths. Did you drill out both bulkhead connectors 16 for the battery and 18 the load feed from the alternator? It feeds splice one from where all the loads are feed from. If wiring hasn't been altered. The other thing is to look at is the ignition connector under the steering column. Here again. 12R battery feed to sw and 12 BK feeds ACC side of fuse box. One last thing! If you did not inspect the battery feed A1 12R wire and alt load feed wire R 6 12 BK. Abandon them! Run new wires in place of them.
Splice one.

Hi Sir,
Thank you very much for your input. Took you some time, so I'll take some time to answer comprehensively as well.

What I did is pretty much follow the MAD solution.

With a few differences :

1. To avoid having to drill both 16 and 18 spade connector locations, I only drilled the 12R side of it (simply because its location on the bulkhead is bigger and easier to drill).
Ran a big 10awg wire through it. Under hood it goes to the starter relay (with a midi fuse). Under dash, I have made the welded splice that MAD shows on the engine side : Soldering 12BK and 12R together. In a way, it does not really makes sense to weld them back with one another. It's the same wire after all... Especially since the AMPmeter is bypassed. Maybe, just maybe that creates a quicker "route" for the current to feed a specific load. This been discussed here quite a bit with guys realizing the "loop" created did not really make sense.
But hey, for the sake of it, I did it too. That clearly does not harm anything anyway.

2. The 12BK from the alt to the starter relay that I put isn't using the older wire (tiny 14awg cable at some point...). It's a brand new 10awg wire all along, and I put a Midi fuse of 35 amps.

3. As mentionned before,I did not use "Fusible link" because if they break, they just break and you have to run a new wire. Instead I put "Midi Fuse" in a small dicated waterproof enclosure. If it breaks, you can swap it in a heartbeat.

Here's my version of it with the MAD drawing modified.

I would think your are going to be doing a headlight relay circuit. Side note for reference. When doing the Alt bypass. Connecting to the alt feed to the starter post and or the starter relay. It is electrically the same as feeding the load from the alt. As long as there is a feed going to splice one some how. A new wire? Via connector 12 or 16 or both but fused. If the amp gauge wires are good. connecting them together would complete the circuit. Pick a path and fuse it.

And that is something I really need to do ! I just did not think of doing this. Thank you for that !

 

[Guss]

That's great that you retain the broadcast sheet.
You can have a new fender tag made from the broadcast sheet.
Prize of a car for sure!

I'm curious, what Pontiac did you restore?

Did not know you could order a fender tag ! Will dig into this, would be cool to retrieve that!
Thank you !

I restored a 1966 pontiac Lemans... But I custom made the roof (and more) of the car. It is very hard to explain the work involved in a few words so :
Check this link if you want to see the car and the idea behind it.

 

[Challenger RTA]

Also check this problem area. The foot dimer switch is bunt most of the time. There is a replacement plug for it. Once you install the headlight relay circuit you will not have a problem with again.

 

[Challenger RTA]

So any how. Now some important safety things out of the way. Welcome to FEBO. Overall you have something good to work with.