Hmm okay I'll check that. I did solder and heat shrink in a new connector. Also, the burnt connector was with the previous alternator. I put on the one from my truck but didn't change the plug out until last week.

How would I check to see if the belt is loose? It does very tight but maybe it's not tight enough?

Could if be possible that the glow plugs are putting too much of a draw on the system before starting?


Edit: The battery light also comes on with the key in the on position before I even start the truck. Is this not normal as well? It goes away after starting up and the glow plugs off, but it's always showing before I turn the truck over.

 

So I plugged in my scangauge that I had for the gas motor. It can't do much on these motors but it does read volts.

When the key is on and engine off, it reads around 11.5 volts. Then when I turn it over, it stays low for a while around 12 ish volts. After a little while it goes up to 13-14 range.

Could this be a bad battery? One of mine is new, but the other one isn't.

 

Remove ground from one battery and check voltage on both after them being charged. I bet you have a weak battery pulling the good one down. Batteries in pairs need to be similar if possible.

 

Do not waste the money on a swamps IDM. I have installed two, swapped between trucks and could not for the life of me hear , feel or see a difference data logging. If you can find a 110 or 120 from a SD and it will be fine vs the 90v I found in my truck (didn't know they made a 90) or 100V std.

You never know what you are getting used. Could your first one been done and the second actually been a junk damaged unit, yes. If your third one toasts right away then there has to be a short, granted I personally have never seen that happen.

Hope you get lucky!

 

Thanks for the info! I ended up going to the local oreillys to test my none new battery and alternator. The older battery came up as good with 1/4 life left. I took the alternator off and it tested good and they tested it like 5 or 6 times.

I ended up deciding I should just go ahead and buy a new battery so I have both brand new ones that are exactly the same. They are both rated at 850 CCA, 1000 CA and 150 reserve.

The one I replaced was a walmart one with a CCA of 810 and a little smaller reserve and CA I believe.

The battery light still comes on when I turn the key, but it immediately shuts off after the vehicle is running now instead of taking a few seconds to a minute.

I sure hope that everything I've done will add up to never having to replace the IDM again! (or at least in like 200k miles)

 

Good deal Max, you have really hung in there!!

 

That Mall*Wart battery is a shade underpowered; two matched 850CCA are recommended. But see above; if one battery is older/weaker than the other, you'll have starting/charging problems. Either replace the older one with one as closely matched as possible to the newer one, or get two new batteries.

The charging system warning light will come on with key on, engine off. That is as expected; after all, the alternator is not charging the batteries with the engine off. This also serves as a bulb check.

 

Don't replace just half of a battery bank except in emergency.

It won't hurt anything to charge them both up thoroughly. New doesn't mean fully charged. Start them out on the right foot, as they are a single large battery once connected.

Can't test ohms resistance on high current circuits, starters that draws 250 amps or better etc. Must test for voltage drop while under load. Low resistance is important for both starting and charging. Alternators lose 30% of their charging juice with just a few hundredths of a single ohm. Not enough to notice at idle maybe but it will choke under any kind of load.