welcome to the site, my first dodge was a 74 W100, I still miss that truck. Good luck and post pic's as soon as you can.

 

Welcome to the site Daniel!

Wiring in our old trucks is pretty simple

Probably the first thing you will want to do is a amp gauge bypass
alot of electrical problems in our Mopars are caused by the bulkhead connector on the firewall due to charging current passing through the bulkhead twice

When you do the bypass it allows you to have two power wires entering the cab I use the spare to power the trailer brake control in my CrewCab,I use it to power MSD 6AL boxes when I install them' stereo equipment,ETC

I have almost 60 years of Chrysler factory service manuals, some in triplicate

Bob

 

Good to know! I have a chilton book with wiring and vacuum diagrams, and I'm thinking about throwing away the shitty ammeter and running the alt wire straight to the battery and then just get a regular voltage gauge. Figured I could kill 2 birds with one stone by upgrading gauge thickness and reliability.

What I really need is a quick fix for the gauges, the oil temp and pressure doesn't work, and the fuel fluctuates based on if I'm moving or stopped.

 

My fuel gauge did the same thing, I put new ground wires on both of my tanks and the gauge works great now. When you take the ground off the cross member I took a grinder to clean and get rid of any rust, just watch where the sparks go. Then put new wire on and spray undercoat on it.

 

Some pics, 1st one was the day we picked it up, it had a roof rack (removed it, thinking about painting it and putting it back on though).

2nd one was when i was doing valve cover gaskets when it still looked a little gross.

3rd one is how it sits now, lookin better but not good enough for me. lol

 

looks like a pretty nice truck. you definitely want to run a new upgraded wire from the alternator to the starter relay. that 100 amp alternator will most likely kill the stock wires. how do you like the 100 amp alternator? i almost want to get one for my 81. i find my stock 65 amp pretty overloaded with all the upgrades i have done. my battery starts discharging the moment i put the truck in reverse.

 

I picked it up for $114, powder coated black, it just bolted in with the stock wires, I do see my ammeter now when the battery is fully charged, it goes from fully charging to middle, fully charging back to the middle constantly. I'm guessing that means the battery is fully charged and its turning off and an via the voltage regulator. Stock for me was a 40 amp and it wasn't enough to power the headlights at night, lol.

 

75 amp should work for you craziewolfie. 100 amp were for police, snow plows, fire trucks etc.....75 amp are almost half as much as the 100 amp

nice truck by the way. looks like a beast. what airfilter is that?

 

double stacked 14"x3" spectre filter

75amp is not enough to power much in my truck. you have to remember you only have about half the max amperage output at idle. plus my backup lights currently pull 20amp. now when you turn on the 20amps of stock headlight/marker light, blower motor, wipers and electric fans things discharge very fast while idling and even faster when i put it into reverse.

 

Only reason I went with the 100 is because is my other truck (Nissan Titan) has a 140 amp alternator and I've played the music loud enough to dim the headlights.

Yeah I double stacked 2 14" spectre filters.

 

the stereo must not be stock if it pulls enough power to make your headlights dim.

 

In my titan it's not, but I do plan on putting a nicer stereo in the dodge with some Offroad lights, fans, etc

 

96-00 caravan dual electric fans usually fit the dodge truck rad pretty good and you can usually pick them up for $40 or less at a junkyard.

 

Looks like im making a trip to the junkyard tomorrow or Sunday lol, just gotta start picking every little thing i need lol

 

if i recall correctly a rebuilt 100 amp alternator was like 130$ approximately and had to be ordered from the local parts warehouse. rebuilt 114 amp on rockauto.com is 74$ without a core. shipping is probably another 20 bucks.

 

those 114amp alternators require special brackets and will not just bolt on to replace a 65 amp alternator where the Tuff Stuff alternator is bolt on. i have even considered ordering one even though it would cost about $150 delivered to my door and i have the special brackets to use the 114 amp alternator. i also have the brackets to use a 120 amp alternator which i think could be replaced with 136 amp alternator that would have been used on the 98 and newer rams.

 

http://www.summitracing.com/parts/tff-7509rfsp/overview/year/1974/make/dodge/model/w100-pickup

This is the one i got. Completely bolted in in about 5 min.

 

With a few very minor mods, a Denso 90/120/136/150 Amp alt can be mounted in the stock location SB or B/RB. Upgrade to 4/6 ga cables, use a Trans-pro #8213 adjustable regulator to dial it in and not overcharge (stock reg WILL overcharge). More than 90 Amps requires double belts or squeal and belt erosion will be annoying.

A 120 amp Denso will do 60-65 amps at idle, all day (night) long. "Rewound" stock frame big amp alts don`t last if pushed, and still have low charge rates @ idle. 100/114/117 amp big frame alts are good, but are HEAVY, take large funky brackets, lo idle charge rate, and will not tolerate hi rpm unless they are the police only 117Amp balanced units. Police only 117 Amp units have a different pulley (does NOT look like small frame alt pulleys), an have drilled balance holes. If buying a reman 117, all bets are off - I seriously doubt they are re-balanced when rebuilt.

SB owners have it even easier: Denso alts w/ double v belts were standard equipment late`80s models - all bolt on stuff. Usually 90 amp, but 120/136/150 amp will bolt in and use same pulley.

Done many of these conversions over the yrs, never any complaints, (save for my bill occasionally... I`m not cheap).

Pic is the original mock up of the first 120 AMP Denso conversion I did 12 yrs ago on my `78 440 PW. ( Yes, I know it shows only one belt, there are two now, this was the original "guniea pig". Entire accessory drive re-configured to "A/C" type. And the fuel line is no longer there). Only mounting mods: pivot bolt center spacer shortened, alt output terminal and shroud shortened. Notice the blackened area under the pivot bolt, belt dust! After a very short run time, nowhere near full output. NEW belt destroyed in less than 3hrs, pulleys perfectly aligned. Squealed like a stuck pig for 30 sec after start up.

 

Hmm, my 100amp has never made a peep at squeeling? But i have new belts as well.

 

Load it w/ 80-90+ Amps, see what happens... If you have access to a clamp-on DC ammeter, do a Voltage/Amperage check - I`d be willing to bet it won`t hit rated output, or hold it. Turn on headlights for ~30 min, then start the truck, turn EVERYTHING on (headlights/heater on hi, wipers etc), see what happens... Max charging should be in by 1500-1800 RPM, no need to go higher. Most alts reach max charging by ~3000 shaft (not motor) RPM.

Standard alts "rewound" to higher output just don`t live when pushed. Only so much room for wire and diodes in the case, not to mention cooling capacity. I`ve got an overflowing milk crate of them waiting for recycle to attest to this fact. Lots of pretty chrome and black scrap metal. Powerma$ter alts seem to be an exception, VERY well engineered, (and $pendy).

I`ve done load testing on the Denso`s: 90% of rated output for 12 hrs straight on my alternator Dyno/load cell, they hold! Even went to 110% for 10 mins, they lived. This is all on used alt`s, never tested new or remans. Denso`s will also take a lot of RPM without issue, 25K on the shaft no worries. Figure most alts run @ 3X crank speed +/-.

I`ve "smoke tested" a lot of alts: SM/LG frame Mopar, Denso, Bosch, Leece-Neville, OLD (10si, 20-25si, CS 85/105, CS 144) Delco, Ford 70/90 Amp side terminal all seem to hold up well. New Delco (F#$%*#^G Delphi crap...), Ford 3-6G and small frame, Motorola, Mitsubishi/Hitachi not so much. Ford 3-6G`s are really finicky about batteries, a weak batt will piss them off.

Bear in mind, these are all OEM used alts tested, no remans. Fun to watch them self destruct, fire is cool... Even better when the rotor frags. Extra credit: .50AE 345 grain SJHP bullet through an alt spinning @ 15k RPM, what a spectacular mess... Who needs reality TV when you can have flaming metal fragments in your own back yard?? Never a dull moment around my place. Time, toys and boredom can be dangerous.

 

thanks for the info and sharing that a denso will fit in place of a stock 65 amp alternator. i wasn't sure if they would. i guess now i got to hit the junk yards. what would i find a 150amp denso in? i already got a 75amp denso i could pull the double v-belt pulley off of.

 

I'm interested in what my alt will put out now, I have a decently expensive multimeter in the truck, might wanna go check it out an see.

I've tested the one on my Titan and its got 65amps at idle, and 140amps at 3500rpms

 

136 and 150 Amp are hard to find used, Cummins trucks, very loaded mini vans/SUV`s are your best bet. 120`s are much more common, late `80`s - early `90`s loaded minivans are good donors. Bosch is also used, especially on Cummins trucks. Make sure you get one w/ a 180* (6 & 12 O`clock) mounting pattern. Once rebuilt, no tags so ID can be difficult. I look at the pivot bolt ear to ID, less distance from alt main body to pivot bolt, more amps. 136/150 amp units have no "hole" between the main body and pivot bolt. 90/120 Amp units have a "hole" you can fit a finger into. American built (Tennesse) units have an extra ground strap on the rectifier pack, a wider front bearing, and wider slip rings/brushes. If the factory tag is present, Amp`s will show as Family 90HS (90 Amp), 120HS (120 Amp), Etc. If the PN begins with a "TN" it`s a Tennesse built unit.

75 Amp and down Denso`s have 13mm shafts, I believe. I`m sure the 30-45 Amp ones are 13mm, have ordered many 5" pulleys for them. 90 Amp+ are 15mm shaft. I never use the 75`s, I install 30-45 Amps w/ 5" pulleys for circle track app`s, 120+ amps for street rigs. 15mm shafts are a common size, so washers/spacers for alignment are easy to find. The 90 - 120 Amp ~`87-`90 ish units on RWD chassis use a common double v pulley, 90% of the time this is what I use. Can get them new from my friendly rebuild shop for ~$6, used for free.

Note: Later alts use a plug in connection for the field wiring, OK for the later serpentine setup, no good for use in stock brackets (clearance issues). Early Denso`s use 2 studs for the field wiring, these are the ones to use for mounting in stock brackets. 136/150 Amp w/ field studs are `96 -`98 as far as I know. Also, some app`s use a 90* adapter/extender that bolts onto the output stud, a handy problem solver for clearance issues.

As I said earlier, SB owners can directly transplant the whole serpentine accessory drive from a 3.9L v6, or 5.2/5.9 v8. Upside: many sizes of alt pulley diameters for the serpentine setup, for fine tuning alt shaft RPM to optomise the alt/crankshaft RPM ratio. Particularly helpful to compensate for low RPM luggers or 7000+ RPM hot rods.

There is a 78 amp "thin stator" alt used in later years, pre-Denso.

 

We got a walking and talking Wikipedia over here! Good info!

 

Wouldn`t go that far, just a lot of hands on and trial and error... I`ve done literally hundreds of auto/rv/marine/equipment custom installations/conversions, as well as many custom 12/24 volt small gas/propane generator builds.

 

not exactly what i want to hear. stuff up here in Canada can get expensive. that new v pulley may cost more than $6. i am hoping the one i have will work since it came off my 91.

the 136amp alternators can be found on 97-01 ram trucks and vans but the 00-01 ram trucks and vans would have that special connector like you were talking about.

i hate serpentine belts. i would rather have a v belt any day. them serpentine belts have a better chance of leaving you stranded on the side of the road. i know my dad has been fighting with the one in his ford for years. it has got a lot better lately but he still carries a spare belt.

 

not exactly what i want to hear. stuff up here in Canada can get expensive. that new v pulley may cost more than $6.

Make friends w/ your local alt/starter reman shop. I`ve been dealing w/ the same one for ~30 yrs, always does me and the people I send there solid. I give him all my cores/leftovers, my alt dyno/load cell spends more time there than at my place... I get new parts for cost+5%+ tax, or less. Usually rebuild shops will sell used pulleys cheap, or just flat out give you one.