Finished up dual battery installation, working well.

[pinballlarry1]

Finished everything a few days ago, just need to see what voltage readings I get at the starter terminal when cranking with one battery and then two batteries. From the sounds of the starter turning, it is a higher rpm. I wired the batteries is parallel like the diesel engine set up.
The drivers side battery tray with everything needed was $75 from LMC. Easy bolt in, just had to drill two holes where the wheel well was pre dimpled.

You must be registered for see images attach

Nice snug fit for a group 24 battery that I already had for a previous vehicle.
I had custom battery cables made from the place in Louisville Kentucky. $80 total shipped, and all my measurements were accurate enough. I upsized the negative cables to #2 awg. Both side headlight ground wires went to a 5/16" screw on the radiator support panel. I was able to clean all the connections and put in 5/16" all thread to make a nice connection stud for everything:

You must be registered for see images attach

The new battery also has a cable that goes from the ground stud to the power steering bracket:

You must be registered for see images attach

The positive wire is #2 awg with positive top post clamps on each end and was wrapped in flexible sleeving:

You must be registered for see images attach

I followed the path of the existing headlight wiring over the top of the radiator shroud. Easy to secure with clamps and zip ties. Since my passenger side battery has both top and side posts, it makes a great junction block for the positive cable. I covered all terminals with protector boots and cleaned the starter connections and firewall junction block:

You must be registered for see images attach

I am still going to install a ground strap from the engine to the frame and some warning labels. Next project is louder horns and the wipers not parking when turned off.

 

[pinballlarry1]

Just a couple more pics of the cable work.

You must be registered for see images attach

You must be registered for see images attach

 

[fast 99]

My first choice wouldn't be a ground to the body. Why not go to the block? To complete circuits ground everything, block to body, body to frame, engine to battery. All battery cable size except block to body. That could be 10 gauge, usually 2 one on each side.

 

[pinballlarry1]

Both batteries negative cables go to the engine block. The original passenger side negative cable (now #2awg) goes directly to the engine as from the factory. The new drivers side battery negative cable goes to the engine via the new stud on the radiator support. Any stock factory ground straps and cables are still there although I am probably going to put in new ones that are one size larger and not mangled. Since I have no cost or weight restraints like GM, I will end up with plenty.

 

[AuroraGirl]

Both batteries negative cables go to the engine block. The original passenger side negative cable (now #2awg) goes directly to the engine as from the factory. The new drivers side battery negative cable goes to the engine via the new stud on the radiator support. Any stock factory ground straps and cables are still there although I am probably going to put in new ones that are one size larger and not mangled. Since I have no cost or weight restraints like GM, I will end up with plenty.

one thing I would change is to clean the power steering bracket where the ground cable connects so it makes a more solid connection. Your grounds are already overkill but its just an idea. cant go wrong with overkill on grounding

 

[SirRobyn0]

I have toyed around with the idea of doing this, but I'd want the second battery to be isolated and I'd want an override switch in the cab. For me there are times in the winter that I need to use the lights from the truck to illuminate something on the farm. Generally that is something broken that I need to fix ASAP. Well currently I leave the truck running, but if I had second isolated battery I could either run the lights off the added battery, or run the starter off the second battery. Either way I'd be sure to have the cranking power even after running the battery down. But the bad thing is with a single V-belt on the alternator that maybe a problem, depending on the output capabilities of the alternator. For me it would mean I'd need to go to a dual belted alternator, which is doable, it's just another thing to do. Maybe one day.

 

[fast 99]

I have toyed around with the idea of doing this, but I'd want the second battery to be isolated and I'd want an override switch in the cab. For me there are times in the winter that I need to use the lights from the truck to illuminate something on the farm. Generally that is something broken that I need to fix ASAP. Well currently I leave the truck running, but if I had second isolated battery I could either run the lights off the added battery, or run the starter off the second battery. Either way I'd be sure to have the cranking power even after running the battery down. But the bad thing is with a single V-belt on the alternator that maybe a problem, depending on the output capabilities of the alternator. For me it would mean I'd need to go to a dual belted alternator, which is doable, it's just another thing to do. Maybe one day.

We had the same problem on the tow trucks using too many amps at idle. However adding an isolator and related wiring was just another thing to break and they do add resistance.

Installed a small 2"or 2 1/4" diameter dual belt alt pully off an Olds, Buick or Pontiac not sure which one. That helped quite a bit. The small pulley did wear out the belts more often and required more frequent adjustment. Have been looking for one of those pulleys for a while now. Haven't been able to locate one but I know they exist.

 

[Turbo4whl]

Installed a small 2"or 2 1/4" diameter dual belt alt pully off an Olds, Buick or Pontiac not sure which one. That helped quite a bit. The small pulley did wear out the belts more often and required more frequent adjustment. Have been looking for one of those pulleys for a while now. Haven't been able to locate one but I know they exist.

CLICK HERE


or CLICK HERE

You must be registered for see images attach

 

[fast 99]

CLICK HERE


or CLICK HERE

You must be registered for see images attach

Thanks, question that was costly.

Really have done some searches and couldn't find it. Bought one but ended up spending $400 on some other items. Merry Christmas to the S Body.

 

[Dleslie212]

Nice!! I have installed the second battery tray, but haven't pulled the trigger on the dual battery setup yet. Hopefully sometime next year

 

[SirRobyn0]

We had the same problem on the tow trucks using too many amps at idle. However adding an isolator and related wiring was just another thing to break and they do add resistance.

Installed a small 2"or 2 1/4" diameter dual belt alt pully off an Olds, Buick or Pontiac not sure which one. That helped quite a bit. The small pulley did wear out the belts more often and required more frequent adjustment. Have been looking for one of those pulleys for a while now. Haven't been able to locate one but I know they exist.

Funny story. Back in the middle 90's we were just scraping by financially for a few years in there, and I was driving a 1973 Dodge van, this old van had just about everything wrong with it that wasn't an absolute requirement to go down the road. One of the plans for our financial recovery was for me to get out of fast food, so took a job mounting tires. At the time that meant going from a $4.00 an hour job to $8.50, but it also meant I had to commute quite a bit further and had to get to work if it snowed. The battery in this old van was not great. It had about enough power to crank the engine over for 3 or 4 short bursts, which was good because it almost never started on the first try cold. Well this one snowy day traffic was nightmare getting though the city to my job, and this old van discharged heavily at idle. Well I got to work ok, but a few hours later when I needed to move I had to use the jump box lol. I'd drained the battery just driving in traffic with the headlights on. No heat so didn't have to worry about that load!

 

[fast 99]

Funny story. Back in the middle 90's we were just scraping by financially for a few years in there, and I was driving a 1973 Dodge van, this old van had just about everything wrong with it that wasn't an absolute requirement to go down the road. One of the plans for our financial recovery was for me to get out of fast food, so took a job mounting tires. At the time that meant going from a $4.00 an hour job to $8.50, but it also meant I had to commute quite a bit further and had to get to work if it snowed. The battery in this old van was not great. It had about enough power to crank the engine over for 3 or 4 short bursts, which was good because it almost never started on the first try cold. Well this one snowy day traffic was nightmare getting though the city to my job, and this old van discharged heavily at idle. Well I got to work ok, but a few hours later when I needed to move I had to use the jump box lol. I'd drained the battery just driving in traffic with the headlights on. No heat so didn't have to worry about that load!

Yeah, Dodge didn't design decent electrical in that era. Many Dodges back then were full amp circuits through junction block and cluster. Was driving one of our 1975 1 ton Dodge tow trucks at night when all of sudden had a new floor light, was on fire where the junction block went through the firewall. Worst truck ever made, hate them to this day.

 

[Copymutt]

Over the decades of owning my K20 Ive run duals w/ isolator for cab over & now straight parallel to keep up w/ the electric plow controls & plow lights. The best deal Ive found on batteries is about $70.00 apiece at Wally World. Any issues and they get replaced free for up to 3 years.
I keep a cut off switch on the factory battery location that kills both and a top off solar charger hooked up when not used for months at a time. Three seasons into that set up & good to go.

 

[SirRobyn0]

Yeah, Dodge didn't design decent electrical in that era. Many Dodges back then were full amp circuits through junction block and cluster. Was driving one of our 1975 1 ton Dodge tow trucks at night when all of sudden had a new floor light, was on fire where the junction block went through the firewall. Worst truck ever made, hate them to this day.

Ya, my van was setup like that where the charge wire came inside to the amp meter gauge on the dash. In more recent years I've owned to class-C motorhomes on the 70's van chassis, up until 2016 when we bought a 99' on a chev chassis with the 454. To be honest I kind of miss the old Dodge's, I know they weren't the best built, but just like my square I always felt I could fix them on the side of the road if needed where as with the newer Chev there are things, like the fuel pump that I just couldn't do on the side of the road, especially if it had a full tank. I do for sure like the 454 over the 360's that I had in the Dodge's.

 

[pinballlarry1]

The ground connection at the power steering bracket was cleaned to bare metal. There are actually 3 brackets that come together at that point so the ground path gets all over the engine from both sides. Since I am 99.99% never installing a camper, the dual battery setup suites my desire of having better starting power and reserve power to all truck needs.