CASE 70XT Touble Starting with new Exide Battery and Newly Rebuilt Starter

I have a 2003 Case 70XT that has had trouble starting especially below 30 degrees. Wont start at all below 10 degrees unless it is plugged in for at least 4 hours. This has been like this since I bought it new. Just the other day, I purchased an Exide AGM battery with 850 CCA @ 0 Degrees (exceeds OEM battery) and still had trouble turning over. I tested with multimeter and had the following - 12.5V sitting cold then drop to 8V when turning over. I then had the starter rebuilt and the only thing that the rebuilder said was the contacts looked a little burnt but still okay and the bearings were a little noisy. He made it like new again and tested it then I put it back in the machine only to find the same drop in voltage. I checked all the grounds back to the battery and all have zero resistance. A mechanic told me that I should consider replacing the starter with a brand new OEM but that is $$$ and not sure if the starter is the issue.

Can someone tell me if there is another way I should be testing to see where the issue is coming from? Could it be a battery issue? Again this has been happening since new and this is the 3rd battery the machine has seen. The 2nd battery was a Duralast with 1000 CCA @ 32 degrees and it lasted 5 years but again had trouble starting in the winter just like the Exide. Not sure if this is just the nature of the equipment or if there is an underlying issue. I was told that I should not see anymore than a 2 volt drop when it is turning over no matter the temperature.... Any help would be much appreciated.

Thanks,
Louie

Though I am not familiar with the exact machine, here's my 2 cents... Check all cables hot and neg, for corrosion/resistance. If it has a preheater/ glow plugs, you might want to check that circuit, too...:IMO

A lot will depend on just how you are taking measurements... for instance where are you measuring the voltage before and during cranking? at the starter? or on the battery posts? Have you done other tests like attaching jumper cables to it to see if it makes a large cranking speed difference... My first thoughts would be with what DIYDAVE said, check ALL cables and connections... in fact remove them and give them a good cleaning/wire brushing and refasten before throwing more parts at it.

Depending on the environment it has operated in the cables could also be degraded by oxidation and contamination of the copper conductors INSIDE the plastic insulation... I usually see this in older machines especially near the ends but you never know. You could do some voltage drop measurements across cables and replace/upsize any that show excessive voltage.

you may consider switching to synthetic 10 30 diesel oil if its pulling the battery down to 8 volts and has been doing it since new it doesnt sound so much like bad connection though it doesn't hurt to check them Sounds like a hard to turn motor maybe pump reliefs are set to high? Have you ever taken it back in to get checked when it was new

What kind of engine is in this? and what kind of starting aids? Was it slow cranking even when new?

I have a 90XT and have had the same issue in cold weather. I've been through all the things
you mentioned. I think you need a top quality industrial battery. I purchased a Deka brand
battery 2 years ago and my machine has always started since. I don't know the size of this
battery but it definitely turns the engine over much better than any other battery I have tried.
The man I bought this battery from said it was the only battery made in the USA. Whether that
it true or not the machine will start. I still leave the floor pan bolts out so I have quicker access
to the battery. I don't think any of these machines have glowplugs. Mine is a Cummins engine.
I do have a button on the dash which when pushed is supposed to add more fuel to aid starting.
I usually start my machine when I am outside the cab.

My 90XT started yesterday in 25 degree temp probably in the single digits when
you factor the wind chill. It turned over for 20 seconds and fired up. Would not
attempt to do that years ago. I replaced the key switch last year and I think that
combined with a good battery made the difference in my case.

My Case 75xt has glow plugs and they really help. Just left of the light switch, spring loaded. Seems to like 30 seconds or more in cold weather. Steve

Similar problem on Case 1840 & 1845C

I would get intermittent starts and thought I had a bad starter. After replacing the starter solenoid and then the whole starter assembly plus some troubleshooting I then thought it was the key switch and added a separate high current start button in parallel which appeared to solve the problem for a while. After checking around I discovered that a lot of Case skid steer owners were adding a high current relay between the battery and the starter solenoid, with the relay coil being activated by the key switch. It turns out that there is a lot of voltage drop from the battery through the key switch to the starter solenoid, such that there is not enough voltage at the starter solenoid to apply enough force to properly close the copper ring switch inside the starter assembly. Adding the relay puts the full battery voltage to the starter solenoid. if you look at the key switch wiring it is about 20 feet of not so heavy wire, through several connectors and the key switch contacts.

Regarding measuring the voltage, are you measuring the voltage at the battery, the battery cable, or at the starter? And what are you using as the ground for the measurement? If you are measuring at the battery posts, then it means extremely high current draw, otherwise there is probably some resistance somewhere in the circuit. Another thing to look at is the grounding cable. Electricity is not fussy as to which lead can be the problem.

Also, if you are using a side post battery, there can be a plastic lip on the battery that can keep the cable connector from properly contacting the battery terminal, which causes the current to go through the steel bolt. This can cause a several volt drop during cranking and make for weak starting.