Mr C
Senior Member
Item No.2 does not apply to Formals. With the last C body re-design, Chrysler eliminated the bulkhead connector. All the wires just pass through the cowl in a big grommet. One of the best things they did.
Electrical Keeps Getting Worse-77 New Yorker
- Thread starter 77newyorker440
- Start date
Item No.2 does not apply to Formals. With the last C body re-design, Chrysler eliminated the bulkhead connector. All the wires just pass through the cowl in a big grommet. One of the best things they did.
77newyorker440
Well-Known Member
I do not remember the headlight switch light or washer light ever coming on when the other dash lights when out, but I will check if they work normally when I get home from school. When the turn signals engage, I believe they do not do anything strange. I did purposely turn the hazard blinkers on as a safety measure since I have no taillights or stop lights. I have the black and white wiring diagram from the FSM, but it does list the wire color next to the wire name, so I will try to use that.
I will report back my findings,
77newyorker440
77newyorker440
Well-Known Member
Hello Guys,
So after doing some experimentation here is what I have found. With the hazards on, the headlight switch light and the windshield washer switch light will only blink in sync with the hazards when the brake pedal is depressed. These switch lights do not work otherwise. This is interesting, as this ties the whole thing together with the loss of brake lights a couple of months ago. Currently, this is leading me to think of a bad dash ground, but I am not sure. Here is a link to a video I made showing the situation: (Sorry it is not the best quality, I am not a big film guy). If you have any ideas or suggestions please let me know.
Thanks,
77newyorker440
Mr C
Senior Member
I find that with Formals it's almost like they designed the electrical with cues to warn the driver something is wrong, like the way your lights are behaving (I could be wrong). Another example I have seen in Formals is that the turn signal will not cycle with a burned out bulb.
I bet that, if you tackle/ fix the brake lights, this will cease.
To that end have I went into my 77 FSM with my morning coffee and found the following:
The ground for the rear lighting is in trunk left rear. Look for a single eye connector grey wire held by a bolt to the body. Brighten that up;
There are 3 looms:
Trunk loom- connects to body loom via a square 3 by 3 connector left rear of trunk.
Body Loom runs from trunk to lower left cowl inside car along the left rocker- connector to trunk via aforementioned 3 by 3...connects to dash by another 3 by 3 square connector in left side cowl (behind plastic kick panel.
Loom in dash- you only are concerned with 4 wires:
Violet/ Black trace- to neutral start switch; Back up lights
Brown/ Red trace- To turn signal switch; via long thin 8 pin connector near base of steering column. Branches to turn signal flasher. The long column connector has a white wire at the end which goes to the brake switch by the brake pedal arm. Purple wire on other side of brake pedal switch fed by Fuse 6 20 Amp.
Dark Green- To turn signal switch; also ultimately fed by the white wire fed by fuse 6 via the turn signal switch.
Black/ Yellow trace- To headlamp switch.- feeds via headlamp switch into instrument panel lights via 5 amp fuse in fuse panel...fuse #1.
All this to say- recommended course of action:
1) brighten up ground in trunk;
2) check fuse 6
Report back.
I bet that, if you tackle/ fix the brake lights, this will cease.
To that end have I went into my 77 FSM with my morning coffee and found the following:
The ground for the rear lighting is in trunk left rear. Look for a single eye connector grey wire held by a bolt to the body. Brighten that up;
There are 3 looms:
Trunk loom- connects to body loom via a square 3 by 3 connector left rear of trunk.
Body Loom runs from trunk to lower left cowl inside car along the left rocker- connector to trunk via aforementioned 3 by 3...connects to dash by another 3 by 3 square connector in left side cowl (behind plastic kick panel.
Loom in dash- you only are concerned with 4 wires:
Violet/ Black trace- to neutral start switch; Back up lights
Brown/ Red trace- To turn signal switch; via long thin 8 pin connector near base of steering column. Branches to turn signal flasher. The long column connector has a white wire at the end which goes to the brake switch by the brake pedal arm. Purple wire on other side of brake pedal switch fed by Fuse 6 20 Amp.
Dark Green- To turn signal switch; also ultimately fed by the white wire fed by fuse 6 via the turn signal switch.
Black/ Yellow trace- To headlamp switch.- feeds via headlamp switch into instrument panel lights via 5 amp fuse in fuse panel...fuse #1.
All this to say- recommended course of action:
1) brighten up ground in trunk;
2) check fuse 6
Report back.
Mr C
Senior Member
By the way, the reason the flashers function is that they are fed by Fuse 5...and we know that is working.
Gerald Morris
Senior Member
I'd say REPLACE or SUPPLEMENT that bonding jumper as well as polish it and the metal it contacts. You can also test the hypothesis by totally disconnecting what you have, to see if things then worsen. Grounding old cars can get tedious, which is why I like to add extra jumpers around the body. Its easy, inexpensive and a sure way to INSURE good grounding of the body and major components.
77newyorker440
Well-Known Member
Okay, I will try that tomorrow and see what happens and report back my results. Today, my dad, uncle and I dropped the gas tank and did not see any ground strap attached, so we were wondering what it is supposed to look like, how it is attached, and if we could just put a wire between the sending unit and the frame to act as a ground. Any ideas?
Thanks,
77newyorker440
Thanks,
77newyorker440
No grounding wire, they used a goofy metal strap as is mostly shown here that goes to the metal on either side of the rubber.
Pic stolen off another recent thread.
77newyorker440
Well-Known Member
GOOD NEWS!
We decided to add a ground strap instead of using that bracket piece, and now, our fuel gauge fully works, about 5 gallons off. Either way, I am just happy that it finally works!!
Also, we decided to replace the fuse in cavity 6, and the brake lights, clock, and some dash lights work!!
Lastly, some more strange occurrences have happened. With the new fuse, now the headlight switch title light and the windshield washer switch title light and the ignition key light stay on constantly, even when the key if out of the car and the doors are all closed so here is my dad's hypothesis:
About 3 months ago, the headlight switch likely went bad. This caused the fuse to blow, leading to the loss of the clock and the reverse lights. This bad switch likely caused the loss of dash lights and parking lights as well. Then, when we got the new fuse since the switch is broken, it is causing the switch title light to stay on, so the solution is replacing the headlight switch and rheostat.
What do you guys think?
Thanks,
77newyorker440
We decided to add a ground strap instead of using that bracket piece, and now, our fuel gauge fully works, about 5 gallons off. Either way, I am just happy that it finally works!!
Also, we decided to replace the fuse in cavity 6, and the brake lights, clock, and some dash lights work!!
Lastly, some more strange occurrences have happened. With the new fuse, now the headlight switch title light and the windshield washer switch title light and the ignition key light stay on constantly, even when the key if out of the car and the doors are all closed so here is my dad's hypothesis:
About 3 months ago, the headlight switch likely went bad. This caused the fuse to blow, leading to the loss of the clock and the reverse lights. This bad switch likely caused the loss of dash lights and parking lights as well. Then, when we got the new fuse since the switch is broken, it is causing the switch title light to stay on, so the solution is replacing the headlight switch and rheostat.
What do you guys think?
Thanks,
77newyorker440
3175375
Senior Member
Good news indeed!
pull the headlight switch and replace it or perform a continuity test on it and have it rebuilt, if it’s possible...
Mr C
Senior Member
Glad it got things functioning again. I will look into the key light/ headlight switch lamp.
Mr C
Senior Member
Headlight switch hypothesis does not work. You had an old fuse fail that caused loss of lights/ clock. The starter relay powers reverse lights via ignition switch and Fuse 4...nothing to do with headlight switch.
Fuse 6 feeds via the purple/ black trace wire into the time delay relay (a bimetallic strip relay) which feeds the ignition light on the column and the headlight panel light as well as the clock.
Headlight panel light is the feed to the wiper panel light in series, so it the headlight panel is lit, so is the wiper panel light.
You said some dash lights...what works and what does not? The panel lights are fed by Fuse #1 (5 Amp) which feeds to the headlight switch tan wire, which activates the panel light circuit.
What I think may be happening:
1) Fuse 1 is blown leading to circuit board illumination being out.
2) Bimetallic time delay relay is no longer functioning, leading to power bleeding over to the column/ headlight/ wiper panel lights as share a connector (pg 41 of FSM wiring diagram- Yellow/ Orange connector).
The strip in the relay should heat up after a period of time, now that Fuse 6 is repaired as it feeds the relay, and break contact which will turn off the column/ headlight panel lamps after a set time period has passed. If it does not break contact, power can bleed over...if I read this right.
Fuse 6 feeds via the purple/ black trace wire into the time delay relay (a bimetallic strip relay) which feeds the ignition light on the column and the headlight panel light as well as the clock.
Headlight panel light is the feed to the wiper panel light in series, so it the headlight panel is lit, so is the wiper panel light.
You said some dash lights...what works and what does not? The panel lights are fed by Fuse #1 (5 Amp) which feeds to the headlight switch tan wire, which activates the panel light circuit.
What I think may be happening:
1) Fuse 1 is blown leading to circuit board illumination being out.
2) Bimetallic time delay relay is no longer functioning, leading to power bleeding over to the column/ headlight/ wiper panel lights as share a connector (pg 41 of FSM wiring diagram- Yellow/ Orange connector).
The strip in the relay should heat up after a period of time, now that Fuse 6 is repaired as it feeds the relay, and break contact which will turn off the column/ headlight panel lamps after a set time period has passed. If it does not break contact, power can bleed over...if I read this right.
77newyorker440
Well-Known Member
Okay, so I will try to get a 5 amp glass fuse, replace it tonight, and report my findings. What should I do in relation to the bimetallic time delay relay? Is there anywhere I can find a replacement for that and where is it in the car? I think I'll probably still order the headlight switch since it was broken before any of this happened, so it would still be a good fix.
Thanks for all the feedback and advice!
77newyorker440
If I may.....I suggest that you repair the known problems first.
The headlight switch. They are inexpensive, and I'm sure you can get one locally.
Part of the headlight switch controls the dash light dimmer function. They are almost always covered with green/blue corrosion by now, resulting in a loss of dash lights.
The flasher units (usually there are 2). When they act up, especially when old (like SOME of us...lol), strange things happen. They are also cheap.
The brake light switch. We replaced a ton of those under warranty back then. Again...cheap to replace. Pay close attention to how many terminals are on the replacement. SOME had 3 (speed control)
The headlight switch. They are inexpensive, and I'm sure you can get one locally.
Part of the headlight switch controls the dash light dimmer function. They are almost always covered with green/blue corrosion by now, resulting in a loss of dash lights.
The flasher units (usually there are 2). When they act up, especially when old (like SOME of us...lol), strange things happen. They are also cheap.
The brake light switch. We replaced a ton of those under warranty back then. Again...cheap to replace. Pay close attention to how many terminals are on the replacement. SOME had 3 (speed control)
77newyorker440
Well-Known Member
Fortunately, I have already replaced my brake light switch, so that is one checked off the list (Not the easiest to find, I could only find one NOS for sale). I am currently ordering the headlight switch and I will look into ordering the flasher units on rockauto.com, as well as looking into replacing Fuse 1.
Thanks,
77newyorker440
Mr C
Senior Member
Relay block is behind drivers side kick panel.
What to do about the relay? Not sure...it's not my car I'm thinking the contacts may be rusted together such that the bimetallic strip does not have the force to break the contact. Maybe open the relay and clean the contacts... either that or replace or unplug.
77newyorker440
Well-Known Member
Okay, so here is my update for today:
Since my last message, my dad and I have just been disconnecting the battery when we park the car and reconnecting it when it is driven as to not drain the battery from those lights staying on.
Today, we replaced the headlight switch, which meant we had to pull off the dash and unplug a few switches and lights. However, about two hours later, it was all back together. Now, we have a fully working rheostat.
Some strange things happened, however. I first tested the new switch without the key in the ignition. First, I tested the headlights and rheostat, which worked like usual. Then, with no key in the ignition, I tested the brake lights, and only the passenger side brake lights turned on. Then, I tested the hazards, which worked as usual. While the hazards were flashing, I hit the brakes, and all brake lights turned on. I then turned the hazards off, tested the brakes, and all brake lights turned on.
Then, I put the key in the ignition, and the wipers turned on with the switch being in the off position. I put the windshield wiper switch in the on position, and the passenger wiper stopped while the driver side wiper when 2x speed. I then turned the switch off, and it turned off.
As you said before, the headlight switch replacement did not stop the problem of the headlight switch title light, the windshield washer switch title light, and the ignition light staying on even when the car is off and the key is out. I will now work on finding where this bimetallic relay is, as I have yet to find it.
Thanks for reading,
77newyorker440
Gerald Morris
Senior Member
I recommend isolating the systems misbehaving, one at a time, and watching for OTHER systems changing behavior. See what happens if you disconnect the wiper SWITCH first. Remove it altogether if practical, then test the leads for voltages. Apparently, each wiper has its own motor. Are THESE fed power from relays, or a switch? I would suspect, even in the more complex year of 1977, that the wipers are still controlled by a switch, with one relay to get direct power switched o from the battery. I hope so anyway. If you have 3 speed wiper motor(s) then running a separate relay for each speed would get insanely complex for the net result.
You likely DO have a relay badly mis-wired, probably as a result of age and wear. Since I have no schematic in front of me, all I can recommend is to isolate the problem components, test, verify, and simplify. You may need to keep that car parked until the wipers are put right up north as you are.....
Good luck!
You likely DO have a relay badly mis-wired, probably as a result of age and wear. Since I have no schematic in front of me, all I can recommend is to isolate the problem components, test, verify, and simplify. You may need to keep that car parked until the wipers are put right up north as you are.....
Good luck!
Mr C
Senior Member
Regarding the wipers...the moment that one was arm was wiping independent of the other, the bushing broke to that arm, and will have to be repaired. It's a job that takes 20 min if you've been in there before- about an hour taking your time. While you're in there do them all. Readily available Dorman part number 49440, even available from Mopar I heard.
They look like this:
As for electrical gremlins you described...when things do not work then come on, it's a symptom of corroded contacts. I've seen it when cycling switches and nothing happens and then the item suddenly comes on (like your wipers) it's likely because the action of cycling the switch cleaned the contacts in the switch permitting electricity to flow again.
The car probably sat.
Get into the connectors and ground points and brighten things up as best you can as a start to establish some kind of baseline confidence that the continuity is there. I'd cycle the switches (wiper, windows etc) with the car off to brighten the internals of the switches.
Are the brake lights now consistent?
They look like this:
As for electrical gremlins you described...when things do not work then come on, it's a symptom of corroded contacts. I've seen it when cycling switches and nothing happens and then the item suddenly comes on (like your wipers) it's likely because the action of cycling the switch cleaned the contacts in the switch permitting electricity to flow again.
The car probably sat.
Get into the connectors and ground points and brighten things up as best you can as a start to establish some kind of baseline confidence that the continuity is there. I'd cycle the switches (wiper, windows etc) with the car off to brighten the internals of the switches.
Are the brake lights now consistent?
77newyorker440
Well-Known Member
Hello Guys, thank you for the responses!
Here is the update for this week. The brake lights are now working consistently. My dad and I recently drove to Moyock, NC and picked up Dorman 49940, and we will be popping those bushings in next week, so I will give you the update on how that goes. My dad and I also did some more research in the Electrical FSM and the '77 Parts Catalogue and found MoPar part 2889 565, which is a time delay relay, which we think is causing our problems, this relay is connected to the ignition light, headlight switch title light, and the windshield washer title light, so I am 95% that this should fix the problem. We found the NOS part on eBay and ordered it, so I am hoping to install it next week, so I can start using the car more regularly again. Below are some pictures of what we found in the FSM and Parts Catalogue. I will let you guys know what happens after the new parts are installed.
Thanks,
77newyorker440
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