What to do under the dash besides this?

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2nup350

2nup350

the four doors are mandatory
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Cataula , GA
"73 Dart. I have to pull lots of things off because of a problem laundry list -wiper bushings, heater core, speedo cable, vacuum hoses. is there anything else I should do while I have the dash all apart? was considering pulling the evaporator core and replacing it with something more appropriate for 134A. and replacing the glove box, mine is kinda alright but still, a nice new one....
 
I would for certain go through the cluster. There are hundreds of threads on this LOL
 
Yes, wiper pivot seals!!! You might also check the threads that address taking the main power feed and return out of the bulkhead connector instead of running it through the ammeter gauge. It's a lot easier to do with all that out of your way.
 
If you pull the bezel and instrument cluster, bench test it with 6v lantern battery before putting back in.
 
New light bulbs including the one in your climate controller if applicable.
Replace mechanical gauge voltage limiter with solid state regulator.
 
str12-340 said:
Yes, wiper pivot seals!!! You might also check the threads that address taking the main power feed and return out of the bulkhead connector instead of running it through the ammeter gauge. It's a lot easier to do with all that out of your way.
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If you do the ammeter bypass and wire it like this, you wont need to bypass the bulkhead connector. First schematic is before, second schematic is after rewiring.

amp-ga18.jpg


Screenshot_20180801-081728.jpg
 
I don’t think anyone repops the evaporators. Mine works fine with R134. I have a completely stock ac system. Don’t believe any of the chatter about having to replace parts of the system. I am not saying newer compressors aren’t more efficient, just that it is not necessary to have a good working ac.

I replaced my dash lights with 3 sided led bulbs that look nice. There are also threads about using led strip lights that look really cool, but I didn’t know that when I did mine.

Definitely read a lot of threads about it. I didn’t know enough when I did mine and will need to do it over at some point. Be sure to solder the connector pins to the circuit board and replace the nuts the ground the circuit board. A pencil eraser cleans up copper traces nicely.
 
Detroit Muscle has lots of great ac stuff and firewall insulation and dash parts.
 
Mike69cuda said:
I don’t think anyone repops the evaporators. Mine works fine with R134. I have a completely stock ac system. Don’t believe any of the chatter about having to replace parts of the system. I am not saying newer compressors aren’t more efficient, just that it is not necessary to have a good working ac.

I replaced my dash lights with 3 sided led bulbs that look nice. There are also threads about using led strip lights that look really cool, but I didn’t know that when I did mine.

Definitely read a lot of threads about it. I didn’t know enough when I did mine and will need to do it over at some point. Be sure to solder the connector pins to the circuit board and replace the nuts the ground the circuit board. A pencil eraser cleans up copper traces nicely.
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I not only solder the pins, but i went to lowes and got copper plated steel brads that fit into the pins from the back as a tight slip fit, cut the excess length off so they fit inside the back of the pins flush. Coat with flux, and solder them in, or alternately you can just super glue them in place. This prevents the pins from pulling loose from the back side where the tangs are peened over. Soldering the pins to the copper traces is good, but the brads prevent the pins from coming loose on the circuit board and pulling out when you have to remove the connector. These 2 methods can also repair a pulled out pin. Test check on reinstallation that the pin heads do not contact the instrument cluster housing or a ground short will occur. You can file the domes on the pin heads somewhat flat, and stick some vinyl tape between them and the gage housing if need be.

Add an extra ground wire from your metal instrument cluster directly to a good ground like the lower left side of the dash under the bolt that mounts it into the body. The cluster is grounded thru its screws attaching it into the dash frame, but a good dedicated ground helps a lot to eliminate dash gremlins.
 
2nup350 said:
"73 Dart. I have to pull lots of things off because of a problem laundry list -wiper bushings, heater core, speedo cable, vacuum hoses. is there anything else I should do while I have the dash all apart? was considering pulling the evaporator core and replacing it with something more appropriate for 134A. and replacing the glove box, mine is kinda alright but still, a nice new one....
Click to expand...

A nice new one will never be as high quality as the original core or evaporator (unless you use Bob at Glenray to recore your original core). Pressure test the evaporator and if it does not leak clean it out with AC flush and reinstall it. I rebuild the RV2 with R134a seals (easy), remove the EPR valve in the compressor (wrong pressures for R134a), flush the lines, evaporator, condenser with AC flush, new R134a o-rings and dryer and fill it up with R134a and be prepared to freeze yourself out. If you live in a moist climate you may need to install a clutch cycling switch that has the thermocouple on the intake to the evaporator to keep it from freezing up (in Arizona I have not had any issues with that).

1972 Duster Build with my Daughter
 
I would also contemplate replacing the harness if you have it that far down. The crimp fittings were never made to last 50 years, many of them are likely high resistance now. The dangerous ones are the ones that are high current (ammeter, AC clutch, blower fan) and get high resistance. You can get the AC and Main harness for for the '73 from Year One or Classic Industries (both M&H harnesses). The main harness is NOT cheap but I always bite the bullet and replace them.
 
Jim Kueneman said:
I would also contemplate replacing the harness if you have it that far down. The crimp fittings were never made to last 50 years, many of them are likely high resistance now. The dangerous ones are the ones that are high current (ammeter, AC clutch, blower fan) and get high resistance. You can get the AC and Main harness for for the '73 from Year One or Classic Industries (both M&H harnesses). The main harness is NOT cheap but I always bite the bullet and replace them.
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This harness has a white connector under the steering column from ignition switch that has been known to melt down. There's a white one out in the engine bay that will melt down too. Crimped wire terminals both sides of those.
Any of them might melt down the connector to headlight switch. A new wiring harness renews only the female side of most connections which might not be a cure all.
 
Question to MOPARAT2000 : Is it possible to substitute a circuit breaker for the fusible links in Diagram B ? Thank you , Tom
 
Second question : In Diagram B , what is the return flow to the battery ? Third : how is all of this regulated ? Does this scheme require an internally regulated alternator ?
 
383Scampman said:
Second question : In Diagram B , what is the return flow to the battery ? Third : how is all of this regulated ? Does this scheme require an internally regulated alternator ?
Click to expand...

Question 2: In all these old cars the return is through the body chassis or engine block.
Question 3: The regulation is done through the field winding not the main charge output so nothing else changes. Your just by passing the ammeter and sending power through the firewall to power the interior electronics. Original brings in the full charging current through the firewall to the ammeter and taps off for the interior electronics from that.
 
Jim Kueneman said:
Question 2: In all these old cars the return is through the body chassis or engine block.
Question 3: The regulation is done through the field winding not the main charge output so nothing else changes. Your just by passing the ammeter and sending power through the firewall to power the interior electronics. Original brings in the full charging current through the firewall to the ammeter and taps off for the interior electronics from that.
Click to expand...

So how do you know if its charging??
 
mopfried said:
So how do you know if its charging??
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You don't know. You can use a hand held voltmeter and check the system voltage while running at the alternator and the battery positive for potential to charge. Then with the engine off, check the voltage of the battery. If its between 12.5 to 13.0 its probably charged. flip the lights on for a couple seconds and recheck. It should be 12.5 to 12.8 V. OTH an ammeter does not reveal battery condition, so this is a useful check anyway when doing a diagnostic without a carbon pile.

Likewise a voltmeter on the instrument panel will indicate whether there is potential to charge. To be most accurate, it needs to be measuring voltage where resistances are a minimum when current is flowing. Checking at the power sources( as described above) is best when there are any doubts.

Jim Kueneman said:
Original brings in the full charging current through the firewall to the ammeter and taps off for the interior electronics from that.
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Not quite.
Alternator output goes to the main splice (except '76) and then directly to whatever is drawing current.
Charging current then goes from the main splice to the ammeter and on to the battery until its satisfied.

Basic power feed and distribution:
upload_2019-1-8_9-9-41.png

Alternator feed provides power when the engine is running.
Battery feed provides power when the alternator is not running or its voltage is higher. It is also the battery's recharging line.
 
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383Scampman said:
Is it possible to substitute a circuit breaker for the fusible links in Diagram B ? Thank you , Tom
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You could. The question is why, and what will be the consequences?

Battery charging is a variable load. A breaker from the alternator output to the battery needs to be large enough to handle the highest charging current expected or you wish to allow.
PLUS the maximum loads for everything else it will send through that wire in addition to charging.
To be a useful breaker, if there is a short to ground, it needs to be sized to open before the wire melts.

Those are the parameters for selecting breakers.
Fusible links handle the variable loads of the battery charging better as long as they have time to cool.
Some diagrams here: Fusible Links in Charging Systems
 
383Scampman said:
Question to MOPARAT2000 : Is it possible to substitute a circuit breaker for the fusible links in Diagram B ? Thank you , Tom
Click to expand...
Damn, fabo didnt give me an alert till today on this. Sorry bout that.

Question 1. No you dont want a circuit breaker on alternator output. Personally i am wiring in a mini denso 50A output alternator. Now 50A is max output. That doesnt mean its running 50A continuous only that it can if need be. I used an 8ga marine grade cable in the harness going to the positive side of the battery with a 12ga fusable link between the 8ga wire and the battery positive terminal. This is the circuit breaker. It can handle a variable load without popping.

Question 2. Alternator is grounded thru the block, and its negative ground wire attached to the battery. Alternator output goes straight to the battery positive terminal. This bypasses the bulkhead connector completely.

Question 3. How is it regulated. The way it normally regulates. Changing the alternators output side wiring to an ammeter and bulkhead bypass doesnt do anything to the voltage regulator circuit. You are not modifying the voltage regulator circuits at all. You are only changing the alternators output path to get power back to the battery, and eliminating the weak point in the circuit which is the bulkhead connection.

Somebody correct me if i am wrong here, but when adding all these circuits and 100 amp alternators which seems to be what a lot of folks are doing now, you would probably want to run the alternators output straight to the battery and just run a volt gage. My 8ga output wire might be a little overkill for a 50A max output alternator, but i know i can upgrade to a higher output one if i need it and the wiring is up to the task.
 
moparmat2000 said:
when adding all these circuits and 100 amp alternators which seems to be what a lot of folks are doing now, you would probably want to run the alternators output straight to the battery and just run a volt gage.
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Matt. When adding circuits with significant load, a distribution point close to the battery and alternator would reduce or eliminate firewall connections carrying the combined high current that they all need. How to to do it best depends on the what the new have to do and whether they will draw on the battery or the alternator.
A nice way to avoid sending power from the alternator through a fusible link for running equipment is to have two circuits from the alternator output. One for charging that has a fusible link, the other to a fuse-relay-circuit-breaker box. If the battery has its own feed that box with a fusible link, then everything is pretty much covered.
 
I have a fusable link on the battery + output side at the starter relay going to the body harness that feeds the firewall as well. Basically where the ammeter wiring used to go through. Plus the fusable link where the alternator feeds the battery. Everything is currently mocked up, but not wrapped.
 
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