Alternator Upgrade

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Grinder

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I want to run a bigger/better/newer alternator on my 67 slant. Has anyone done this? I want to ad electronic ignition,stereo,fog lights,and possibly an electric fan,a/c,and cruise controll.Is there any alternators that will fit in the stock location? Im not sure what size I need to go with,but the stock unit cant even take my lights and wipers on at the same time!
 
First, something is wrong with what you have now. High beams+wipers+heater are well within the capability of the round-back 35 amp unit. When you say the current setup can't handle lights+wipers describe the failure. Wipers slow down? Lights dim? Ammeter show a draw? Voltage drop below 13.5?

The first thing I would do is clean EVERY connection in the car starting with the battery and chassis grounds. Next I would bypass the ammeter. Then, and only then would I swap over to a later 65 amp squareback alternator and electronic regulator.

Or you can skip cleaning all the connections and just bolt on one of those 100 amp Summit alternators. The first connection to catch fire was your original problem...
 
Hahaha thats one way to do it.Will do clean up on the grounds! What is the ammeter and how do I bypass it?

When comming to a stop my lights dim wipers slow down.Also at speed with lights and wipers on,when I hit my blinker it blinks real fast,and as I slow down so do the blinkers...what do you think?
 
You have high resistance in the system. Clean ALL the grounds and make sure your firewall connector is clean, tight and in good shape. Each lamp assembly needs to have a clean ground as well.

The ammeter is the instrument which shows charging/discharging of the battery. These are problematic for two reasons. First, ALL of the output from the alternator goes through this gauge as well as several feet of wire and the firewall connector (twice). Second, when (not if) the gauge fails, it is the same as losing your alternator, you are on the battery.

The best way to keep this part and the firewall connector from melting down is to remove the majority of the charging load from it. Run a 10 AWG wire from the binding post on the back of the alternator directly to the positive battery connection on the starter relay (use a section of fuse-link). Down the road if you chose to add a monster stereo, upgraded lighting, etc.. connect their main loads here, possibly adding a small fuse box. This keeps the service loads fed directly by the alternator and only switching loads are routed through the firewall connector and dash wiring. New cars are wired this way.
 
Thanks Cheif! Do you know of any diagrams I could look at? Im not much of an electrician,so I dont quite grasp this upgrade.I know what you are saying,but I dont know how to translate it into something tangeable.:read2:
 
There are books on automotive/hot rod electrical systems out there. I would suggest educating yourself on the fundamentals before tearing in too deep. There may be some internet resources that would be worth looking for such as http://www.madelectrical.com/electrical-tech.shtml but don't limit yourself to these.

Locating a factory service manual would provide you with wiring diagrams, and should be a priority.
 
Where is my chassis ground.I cleaned everything else,and installed a new negative battery cable,still have the same problem!
 
ok first of all,,cleaning the connections is a big plus,,,but,,,,pre 1970 mopars are a single field charging system,,and they do not use a constant charging voltage regulator,,,all 1969 and earlier mopars,,when at idle,,are barely charging,,turn on your head lites and you can watch them dim and then get brite,step on the brakes,,it drawls current as well when at a traffic lite in gear,,head lites on,,1970 and newer mopar used a constant charging voltage regulator,,,that cured this problem,,

you can convert your car to this later charging system,,very easily,,you wil need a dual field altenator,the newer voltage regulator,,the 3 wire plug for the regulator,and you will have to add one wire from the altenator to the regulator.
and yes you should eliminate the amp meter,,either eliminate and or install a voltage gauge,,

you can get a diagram of most any 60/70 model mopar from www.classicwiring.com nice color coded wiring diagram,,,

this conversation is easier then it sounds,
 
Thank you for that.What cars can I rob these parts from the junk yard?Does it have to be an a body?

Also another problem I am having.t even happens at speed.The dash lights pulsate.Instead of just staying bright they go bright-dim-bright-dim etc...Any ideas?
 
the dash lights,, may be a bad or dirty connection,,or bad ground,,,start looking around,,unless ur voltage regulator and or alt is that bad,,,but my guess,, bad connection,,,maybe at the head lite switch,,wiggle the knob, it may be the dash dimmer in that head lite switch

you can get the pats out of any 1970 and up mopar,,up to some where in the early 1980s i think,,,the regulator any parts store,,ask fro a regulator from any 1970s car,,the plug for that regulator at a junk yard,,i think mopar performance sells it but not sure,,dual field altenator square back,,ge a good rebuilt,,not a cheapy,,
 
Your chassis ground is the 10 AWG pigtail on the negative battery cable which should be attached to the body.
 
Upgrading the charging system is fine and dandy, easy to do too. There's a kit for the wiring available at uscartool.com or parts yard source as mentioned above but...
until you find the fault in the origial system the upgrade probably wont improve squat. So here's what I suggest...
First replace your positive and negitive battery cables with new and heavier gauge. Check for improvement.
Next go into the instrument cluster and remove the red and black wires from your amp gauge. Clean those ring terminals and place both together on one of the studs and tighten securely. This will take the amp gauge (a weak link) out of the circuit. Check for improvement. Post or PM results.
See I wont recommend that jumper wire from alt post to battery. Extra wires draped across an engine can melt and cause more problems than they solved. When we do get to the upgrade we will add a blue wire from regulater to altenater but we'll route and tape it into the original harness. Do it right or don't do it at all.
 
I had a similar problem with dim headlights and could not find any wiring/ground issues. I bypassed the amp gauge and it didn't help. I read an article on this forum about this problem and it suggested installing 2 relays to control the headlights (lights would dim at idle and the alternator was putting out). I mounted relays on the driver's fender and routed the current thru 2 20 amp circuit breakers (they recommended fuses - fuse blows and you lose your lights). The relays take the load off the wiring and headlight switch which was a large current draw. It works great. I use my headlights day and night. I haven't had any problems in over 4 months. Here is a pic.

headlightrelays-vi.gif
 
I certainly wouldn't advise draping a wire across the engine. That is the sort of hackery that should be avoided. Any additional wiring should be routed with, and secured to original harness locations. The direct connection between the alternator and the positive battery cable removes a significant load from the firewall connector as well as the ammeter.
 
C130 Chief said:
I certainly wouldn't advise draping a wire across the engine. That is the sort of hackery that should be avoided. Any additional wiring should be routed with, and secured to original harness locations. The direct connection between the alternator and the positive battery cable removes a significant load from the firewall connector as well as the ammeter.
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I also agree with this comment! getting the load off the firewall block and the dash wiring is the way to go. routing the wire safely from the alternator to the battery connection goes without saying. I've pretty much revamped the whole harness from my 66 cuda and will be installing a volt meter in the instrument panel when I get to that point. Joe
 
I didn't mean to ruffle feathers or discount someone elses input. With all the half assed wiring messes I've seen in customers cars I know what they might do without complete instructions. I never want a user here to follow up post. "MY CARS ON FIRE !" after I suggested something.
I fully understand what that added wire does. It bypasses the problem. It also bypasses some safety features. The charging system in these cars worked fine when new and its compoents engineered to carry the required amount of current and no more. Sure they get weaker with age and use. Finding and replacing a faulty headlight switch, dimmer switch, whatever and replacing that just makes more sense to me than adding wires and relays even though its not nearly as easy. To each his own. Happy moparing
 
Please do not hack the wiring harness. It makes a future owner question the lineage of POs when trying to sort out problems.

Typically the car is grounded by a 4 gauge wire from the battery to the engine block. A flat braided cable is usually connected to the rear of the cylinder head, (Pax side on V-8s). The other end connects to the firewall to ground the body.

The ammeter is wired into the run circuit. Fry the ammeter and the car will start but die as soon as the key is released. Most ammeters in A-bodies are calibrated for ± 40 amps. Easiest by-pass for the ammeter is to put both wires on the same gauge post. Personally gained the above information by putting an 80 amp alternator into a 66 Dart.
 
WOW! This is a great wealth of info!Thank you all! My old battery cable did not have a 10 AWG pigtail grounded to the body.My new one has a little piece comming off of it for this.Should I connect some wire to is and ground it somewhere?If so where?
 
Yes, you should do this. There will likely be a screw or screw hole near the battery on the inner fender or radiator support. Add one if you need to.

Not all cars had an additional ground strap between the back of the engine and the firewall. I think this came along in 71 or so. If you see one in a junkyard, grab it and add it to your car.
 
C130 Chief said:
Yes, you should do this. There will likely be a screw or screw hole near the battery on the inner fender or radiator support. Add one if you need to.

Not all cars had an additional ground strap between the back of the engine and the firewall. I think this came along in 71 or so. If you see one in a junkyard, grab it and add it to your car.
Click to expand...


Could I use one of the radiator bolts? If I have it inbetween the support and radiator mounting bracket? Just dont want to add a new hole if I dont have to.
 
Anywhere really. If you loo closely you should find a headlight ground wire screwed to the radiater support. Factory had no reservations about adding a screw hole to the radiater support on later models.
 
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