Electrical Keeps Getting Worse-77 New Yorker

77newyorker440

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Hello Guys,
Many things have happened with the Chrysler's electrical system since I last posted here, so I am going to lay them out in chronological order to hopefully make sense of this issue.

Since I purchased the Car-Have never seen map light work due to bad switch, gauge cluster lights are working but very inconsistent and dim

2 Months Ago-Brake Lights Stop Working

Today (First Time Driving in a Month)-No Parking Lights (Front or Back), No Brake Lights, No Gage Cluster lights, Key-In Buzzer is pretty inconsistent, only turns on when headlights are not on.

What works-Ignition, Headlights, Reverse Light, Turning Signals, Horn

Any clue what is going on? My guess is that I have a blown fuse, but that wouldn't make sense, according to the fuse lists below:

Cavity 6, 20 Amp: Lighter, Stop (Doesn't Work), Dome, Aft. Dome and Trunk G/Box (Doesn't work), Map and C/Lt., Time Delay Relay for Ignition Switch Light (What is that??), and Key-In Buzzer (Does Work), Clock (Doesn't Work).

Cavity 7, 20 Amp: Side Marker Lights (Don't Work), Parking Lights (Don't Work), Tail Lights (Don't Work), License Lights (Don't Work), Instrument Lights (Don't Work), Turning Signals (Work).

Does anyone have any ideas on what I should do, as this electrical problem seems to just keep getting worse?

Thanks,
77newyorker440
 
I think you may have a grounding issue for the body. Try using your jumper cables to ground the front fender to the negative post on the battery and see if the marker lights come on. There is usually a ground strap to the core support on the driver side front fender that supplies a ground to the body, there is often another strap from the rear of the engine to the firewall.

Dave
 
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For general principles, check the continuity of the fuses mentioned in your post. Sometimes, a fuse can look good, but actually be disconnected internally at the ends.

Do check the wiring schematics in the FSM (download at www.mymopar.com, if you don't already have one) and look for grounds on the forward lamp harness. On some cars, there should be one ground on each side of the harness. Same on the rear lamp harness, too.

Do make sure the engine is grounded to the main vehicle body. If it isn't, eventually, a ground will be sought and found through another component. A shifter cable, for example, or similar, sometimes. Otherwise, a "back-feed" through another circuit can happen, too, causing strange things to happen.

Just some thoughts,
CBODY67
 
The Two Sages above have both given you a strong hint regarding GROUNDING, which I heartily re-iterate. I run a bonding jumper ground from the big #4 negative wire from the battery, along the top of the intake manifold, picking up the coil and distributor, and connecting the engine block to the firewall. There SHOULD BE a substantial grounding strap connecting the rear of the intake manifold surface to the firewall. If you lack that, make one of nothing smaller than #10 AWG wire and be SURE to connect to clean, shiny metal on both ends.

If you DO have what should be there, then check it to be sure it still is in solid electrical and mechanical contact at your firewall. My understanding of Formals like a '77 is that the passenger compartment rides with a fair bit of rubber insulation between it and the frame. This makes the bonding jumper all the more important.

Now, going beyond grounding, a horse we've whipped into dog food cans by now.

1.) FUSE BOX! (re-reading your list of malfunctions inclines me STRONGLY toward this likelyhood.) In addition to deceptive appearances of SFE fuses at times, the CONTACTS in those boxes CAN AND WILL CORRODE TO USELESSNESS! Get a good tester and make SURE you have power at BOTH ends of EACH AND EVERY fuse in there. You will need to turn the accessory switch on for some of these, and perhaps the ignition itself for a few key circuits. If any of these fail to show power when they should, then inspect both the fuses and those contacts. I have a treacherous contact which feeds all the dash lights as well as the brake lights. If it vibrates loose, these don't get power, and I must press it firmly back into service. Thus far, its worth the occasional trouble to just press this nuisance tab into place and resume driving, but I'm not put out of countenance easily by lights going out on me, as folks know.

2.) BULKHEAD CONNECTOR!! The OTHER Major Suspect in creeping electrical breakdown in C body and other Mopars of the same period is the electrical bulkhead connector. I suppose that for cars designed to last 5 years, this thing was OK, but ours now are 42-60 yrs old, and will only continue to age. This wiring bulkhead is a MAJOR SOURCE OF MALFUNCTION!! Check your connections here, and clean them up, then grease them after cleaning. Dielectric grease is nice, but others can do in a pinch. You owe it to yourself to look this thing over regardless of what actually ails your wiring, if this isn't part of it...YET!

I punched through a few of the heavy current connections through this thing, pulling #10 wire straight through in one instance, and running another through a rubber grommet in a nearby hole in the firewall. I've read that cop cars were wired just so from the factory. The less connections in a circuit, the less chances of malfunction.

I reckon I've given you a couple good afternoons of "rat hunting" as we called it in my electricians apprenticeship decades ago. See what sorts of vermin you can find, and let us all know!

Happy Hunting!
 
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The "Torsion Quiet" Fuselage cars had more rubber isolation than the prior C-bodies did. Including, for the first time, at the rear axle-to-leaf spring interface. The later Formals had about the same number of mounts, but they were physically larger, usually.

The 65-68 C-bodies also has "isolators", but they were more like non-metallic washers/interfaces which were more for the interruption of "noise paths" between the stub frame/front body section and the main body structure than as "absorption" items. At least from what I've seen in the FSM and on the cars I've been around. Possibly one reason the slabs tend to be more solid-feeling than the fuselage cars tend to be?

I have not mentioned the 1969 Fuselage cars, specifically, as I have not researched to see if they might be a hybrid, of sorts, betrween the 1968 rear axle mounting and the rubber-isolated 1970 "Torsion Quiet" cars. Somewhere, there's an advertising graphic of what the "Torsion Quiet Ride" componenrts are.

Just some thoughts,
CBODY67
 
For general principles, check the continuity of the fuses mentioned in your post. Sometimes, a fuse can look good, but actually be disconnected internally at the ends.

Do check the wiring schematics in the FSM (download at www.mymopar.com, if you don't already have one) and look for grounds on the forward lamp harness. On some cars, there should be one ground on each side of the harness. Same on the rear lamp harness, too.

Do make sure the engine is grounded to the main vehicle body. If it isn't, eventually, a ground will be sought and found through another component. A shifter cable, for example, or similar, sometimes. Otherwise, a "back-feed" through another circuit can happen, too, causing strange things to happen.

Just some thoughts,
CBODY67
I second this, clean the fuse cavity well, lightly sand the connection
 
I second this, clean the fuse cavity well, lightly sand the connection

There is a fellow on eBay who sells replacement clips for the old fuseboxes. He sells repop plastic boxes too. None of his wares run cheap, but I've bought other items (body parts) from him which were good quality, so expect his wares will be good. When I tire of diddling the old clip in my original box, I probably will buy new stuff from this man. Emery boards work well for cleaning up the old connections, to a point.
 
There is a fellow on eBay who sells replacement clips for the old fuseboxes. He sells repop plastic boxes too. None of his wares run cheap, but I've bought other items (body parts) from him which were good quality, so expect his wares will be good. When I tire of diddling the old clip in my original box, I probably will buy new stuff from this man. Emery boards work well for cleaning up the old connections, to a point.
Good to know, I have to do it every year to my charger, getting old..
 
Hello guys, thank you for all of the replies, I read over your messages, and then I tried the jumper cable method, so I connected the battery post to the body using the cables, but it gave no changes to the problem.

I then investigated the ground strap that goes from the back of the engine to the firewall and discovered that it is absolutely soaked with oil and dirt from a valve cover oil leak. I am going to try to clean it up this weekend and I will report back if that improves the situation.
 
Hello guys, thank you for all of the replies, I read over your messages, and then I tried the jumper cable method, so I connected the battery post to the body using the cables, but it gave no changes to the problem.

I then investigated the ground strap that goes from the back of the engine to the firewall and discovered that it is absolutely soaked with oil and dirt from a valve cover oil leak. I am going to try to clean it up this weekend and I will report back if that improves the situation.
You need to check grounds at these components also. Car starts so chassis ground is okay.
 
Hello guys, thank you for all of the replies, I read over your messages, ....
I then investigated the ground strap that goes from the back of the engine to the firewall and discovered that it is absolutely soaked with oil and dirt from a valve cover oil leak. I am going to try to clean it up this weekend and I will report back if that improves the situation.

Oil and dirt won't degrade the conductance of the ground strap unless it somehow corrodes the strap where it contacts the 2 surfaces its supposed to bond. Oil in fact will help preserve it from oxidation. Many an "Old Moparian" has recommended packing the wiring bulkhead connectors with bearing grease to preserve and protect them. I prefer CRC dielectric grease, formulated just for protecting electro-mechanical junctions, but belabor this matter in order to enlighten you.

Use a trustworthy ohmmeter, and see if ANY discernible resistance exists between engine block and firewall. (I don't expect any.) You then may want to refer to myt "To Do List" from a day or 2 ago. Is there a pink wire from the fusebox that feeds the brake lights and such? How about a yellow wire going to the glove box lights, ash tray lights and such? If these conductors are dead, then you should ru back to the fuse box, replace the dead stuff IN the box, and see if that improves things.

Also, MOST IMPORTANT, DID YOU GET A DECENT WIRING DIAGRAM? Try this:

http://www.mymopar.com/downloads/AutoWiringBeginersGuide.pdf

then one for your specific model.
 
For general principles, check the continuity of the fuses mentioned in your post. Sometimes, a fuse can look good, but actually be disconnected internally at the ends.

Do check the wiring schematics in the FSM (download at www.mymopar.com, if you don't already have one) and look for grounds on the forward lamp harness. On some cars, there should be one ground on each side of the harness. Same on the rear lamp harness, too.

Do make sure the engine is grounded to the main vehicle body. If it isn't, eventually, a ground will be sought and found through another component. A shifter cable, for example, or similar, sometimes. Otherwise, a "back-feed" through another circuit can happen, too, causing strange things to happen.

Just some thoughts,
CBODY67
Oh yes. Among my vehicular hoard is a '76 Winnebago (Dodge B-van cutaway chassis) where the lights acted as if they were possessed: shifting into reverse activated the brake lights, for one example. After much failure at troubleshooting, I discovered that the ground connection for the taillights had loosened.
 
I am surprised that no one recommended getting a FSM. Factory Service Manual. They are cheap and you can get originals on EBAY or if I have a flashback this morning I'll post the web address of a company that repops the FSM in paper and CD. I have a 78 NYB that sat for 30 years outside and not one electrical element in the whole dang car worked. I was chasing electrical demons and not getting anywhere until I got the FSM and figured out what wires went where.


There is cheaper sets.....you have to look for them.

It wouldn't hurt to buy a factory parts manual.....if you plan on keeping the car.

1977 Chrysler Plymouth Dodge Factory Service Manual Set Original Shop Repair | eBay

s-l400.jpg
 
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I am surprised that no one recommended getting a FSM. Factory Service Manual. They are cheap and you can get originals on EBAY or if I have a flashback this morning I'll post the web address of a company that repops the FSM in paper and CD. I have a 78 NYB that sat for 30 years outside and not one electrical element in the whole dang car worked. I was chasing electrical demons and not getting anywhere until I got the FSM and figured out what wires went where.


There is cheaper sets.....you have to look for them.

It wouldn't hurt to buy a factory parts manual.....if you plan on keeping the car.

1977 Chrysler Plymouth Dodge Factory Service Manual Set Original Shop Repair | eBay

View attachment 420578
Yep, I purchased one about two months ago, I just did not currently have it with me as I was away for a bit, but i will check it tomorrow and see what I can find
 
Oil and dirt won't degrade the conductance of the ground strap unless it somehow corrodes the strap where it contacts the 2 surfaces its supposed to bond. Oil in fact will help preserve it from oxidation. Many an "Old Moparian" has recommended packing the wiring bulkhead connectors with bearing grease to preserve and protect them. I prefer CRC dielectric grease, formulated just for protecting electro-mechanical junctions, but belabor this matter in order to enlighten you.

Use a trustworthy ohmmeter, and see if ANY discernible resistance exists between engine block and firewall. (I don't expect any.) You then may want to refer to myt "To Do List" from a day or 2 ago. Is there a pink wire from the fusebox that feeds the brake lights and such? How about a yellow wire going to the glove box lights, ash tray lights and such? If these conductors are dead, then you should ru back to the fuse box, replace the dead stuff IN the box, and see if that improves things.

Also, MOST IMPORTANT, DID YOU GET A DECENT WIRING DIAGRAM? Try this:

http://www.mymopar.com/downloads/AutoWiringBeginersGuide.pdf

then one for your specific model.
Hello Sir,
Thank you for letting me know, I will be working on your to-do list throughout this week. I do have a pink wire going to the brake light switch, and I will have to check on the color of the wire going into the glove box light. I do have the wiring diagrams from the FSM, which are helpful for understanding the layout but a bit complicated, I am going to look into the fusebox stuff with my uncle to see if we can find anything out of order, and I will report back with our findings
 
Also, quick update, when I turned my hazards on today, as we took a quick drive to test the new suspension and show my uncle in the neighborhood, after driving for about 5 or so minutes, the headlight switch light and the windshield washer switch light began and continued to blink in sync with the hazards, which continued until I turned the car off. Is this due to a bad ground within the dash?
Thanks,
77newyorker440
 
Also, quick update, when I turned my hazards on today, as we took a quick drive to test the new suspension and show my uncle in the neighborhood, after driving for about 5 or so minutes, the headlight switch light and the windshield washer switch light began and continued to blink in sync with the hazards, which continued until I turned the car off. Is this due to a bad ground within the dash?
Thanks,
77newyorker440

Hmm, headlight switch indicator light in sync with the hazard lights? This MAY be due to a bad ground for the dash. Do they work NORMALLY BEFORE you engage the hazard blinker? If so, then your short circuit may be in the circuit board in the dash. How about when the turn signals engage? Try that to compare. Now, did you PURPOSELY TURN THE HAZARD BLINKER ON? That too needs to be examined.

Pity I'm not there. These kinds of problem intrigue me. It MIGHT HELP if you can find a COLORED wiring diagram for your ride. Google for that. I recall there is a maker of those for some years....

Keep us up to date!

Gerald
 
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