New battery won't start without a jump

Hey all!

I have a 93 idi with 175,000 miles on her and have had some work done this summer. I'm thinking I have some faulty electrical wiring? Whenever I try to start her without a jump it seems as if my battery is dead. Really weak cranking. But when I throw the jumper cables on and let it sit for 5-10 minutes it cranks hard and sure enough she comes alive. Just curious what could it be? Ive cleaned the terminals on the left battery but not on the battery on the right. Any ideas?

All you are doing with the jumper cables is adding another battery. Apparently one of your batteries is no good. One lousy battery will pull the other good battery down with it. That is why when using two batteries, you always replace them in pairs. When they are paired up, both batteries are only as good as the weakest battery.

^^that

chitty connections will do this too

What cca rating batteries did you buy?

My 94 F250 was doing the same thing. The problem was at the alternator connection. Make sure the alternator is charging.

Like wes said got good batteries and check your cables are they all corroded an crappy if all checks out good check grounds your probably like me and hit the ground to the motor

Definitely make sure the batteries are recharging, and verify your connections.

I just got back in the house from helping the oldest son fix this on his 89. His wouldn't spinning quite fast enough to start cold. The glow plugs are currently disconnected, so we are only trying to spin the starter. Understand there are differences in the early 92 and older V-Belt engines, vs the early 92 through 94 serpentine belt trucks. One being the serpentine belt engines have a 3G internally regulated alternator, where the V-Belt trucks have a 1G externally regulated alternator.

Make sure you have a good connection from the charge terminal on the alternator to the starter solenoid on the passenger fender.
Verify the plug on the alternator is plugged in, and the electrical connections are actually connected. I normally will push down on the wires that come out of the back of the plug.
If it is the 1G external regulator, make sure the plug is plugged in, and all the wires are connected. I had to fix ours the other day when we picked up the truck because someone had cut all the wires at the regulator plug on the passenger fender and rewired it incorrectly.
Verify the battery connections at all the battery posts. We just put the batteries in last week, and between the change in temperature and the vibration the terminals vibrated loose. This was one part of our problem.
Especially if it's a V-Belt engine, verify the belt is tight and not slipping. Ours needed tightened a bit, it was slipping just enough you could only hear it chirp when the hood was up. This was our other problem. Re-tightening the battery terminals, and tightening the belt we went for 13.3-13.4 to 14.7 at idle.