6.0 Newbie here who will probably be in over my head but it will be fun. Bought a 2005 Excursion that has about 125k miles but plenty of issues about 2 months ago. Engine has run pretty strong and started easily that entire time. I know it eats or leaks coolant somewhere and drips a little oil but seems to get where it needs to. Until this week. I have had 2 issues and I am not sure if they are related so I will tell the whole story.

Drove to meet up with some friends Wednesday. When leaving to head out, it would not start. Seemed to be turning over cleanly but would not run. Kept trying. Opened the hood like I thought I would see something (knowing I wouldn't). Closed it, got back in, and it cranked like normal. Drove to a couple of more stops and everything seemed fine. Left late Friday evening to visit a friend about 30 minutes away. All was good but about halfway there, I notice the airbag light is on. I honestly couldn't remember if it was normally on or not but it caught my attention so I think not. Just a few minutes later, all the gauges went to zero and the radio shut off. The panel also seemed to dim. Engine is still running fine. They all come back on a couple of minutes later then shut off again. A few minutes later, the AC goes off. I try to put down a window and it doesn't work. I pull off the highway and I notice that the lights flicker with the blinker. I get to a gas station and pull in. I shut down. It doesn't want to start back up but then it does. Gauges still down. I drive a tad and it shuts down when I hit the brakes. I repeat this cycle a couple of times to get parked somewhere safe. I call roadside assistance to get towed and start googling.
Fast forward to the truck being dropped at my house. I start it up and all is fine for a couple of minutes and then it all goes down again. I didn't try to drive it this time. I got out the multimeter and the passenger side battery is reading about 12.5V and the drivers side is 9.6V. I start it up and test the voltages and they are still the same. This leads me to believe the alternator is bad. I put the batteries on chargers so I can take it to the local store later to get the batteries and alternator tested. Get home from work and try to crank it and have the same issue as Wednesday. Turns over good but never starts. I give up for the night.

So my question, anyone have any clear idea what might cause all of this? Is it possible that the starting issue is related to the electrical issue? That doesn't really make sense to me but the timing is suspect. I really need to take it on a 6-7 hour drive tomorrow but I do not want to be stranded.

Thanks in advance.

David

 

One additional odd note. With the batteries charged, the gauges were back, however the fuel gauge was reading empty and the low fuel light was on. In reality, there are over 30 gallons in the tank.

 

Maybe, maybe not.

The discrepancy of battery voltage. The alternator charge to the passenger battery flows to the driver's battery with the crossover cable. So your low battery voltage on the driver's side is not necessarily an issue of the alternator. You could have a bad battery on the driver's side that is taking down everything, or, as we've seen in the past, a bad cable or connection between the batteries. A bad negative cable on the driver's side could also isolate that battery.

So first off, as we have learned in the past, post up pictures of your two batteries so we can see the cables and the terminals.

The batteries should be charged individually and tested for capacity at AutoZone, Advance, or whomever. They do it for free. If you can't get a printout, write down the values and post them here.

If the driver's battery is not well connected, the low voltage can cause all the problems you mentioned.

You might also have a cluster issue or a relay issue, but the battery situation has to be dealt with first.

 

With everything back after the batteries are charged, leads more to a driver's crossover or negative cable issue.

 

Thank you Jack. That makes me feel a little less overwhelmed. Here are the battery pics. If I can get it started, I will take it to the store. Also, after trying to start for about 10 minutes last night and again this morning, the drivers battery was at 12.6V and the passenger at 12.3V.


Driver's Side Battery

Drivers Side Positive Terminal

Drivers Side Negative Terminal

Passenger Side Battery

Passenger Side Negative Terminal

Passenger Side Positive Terminal

 

So based on what I am understanding, I should have continuity between the 2 positive terminals and both batteries should theoretically read the same voltage even if one is bad. I just tested and could not get continuity between them with my multimeter which would indicate a bad crossover, at a minimum. Is this correct thinking?

 

Based on this, I took a set of jumper cables (cheap ones) and connected the batteries. Still would not start. I am going to charge the batteries back up and try again. I may put both the red and black on the positive to make sure I have enough gauge between them. Should I also be able to see continuity on the ground side?

 

Two different batteries - we always want to replace them in pairs, otherwise when you have one that is stronger than the other, it will constantly be trying to charge up the weaker battery. Signs of previous corrosion on all cables and taped up ends means you might have unseen corrosion up under the tape and running under the insulation - you're going to want to clean all this up and inspect a little ways up each cable. Also check the other ends of the grounds and make sure they all have clean and tight connection.

If it were me, I'd start with two new batteries and get into that cabling clean up and see where you are. Hopefully your alternator is just fine, but let's start with some basic stuff...

 

That's a mess. If you refuse to spend any money then at the very least those battery connectors need to be completely disassembled and cleaned, wire terminals redone if wires are corroded in terminals. Of course battery posts cleaned. Also the related battery grounds at frame and block. Even then that's temporary those quick repair battery terminals suck. TooManyToys has a good video on how the stock wiring is going into nice upgrades.

All that said this may not get you running, but it really needs addressed from those pics, Good Luck

 

Back from yard work.

It looks like the previous owner was trying to work out issues and not buy new cables. The factory terminals are not that great, therefore, the replacements. You don't have to have the batteries in the vehicle to get them tested; it's actually better if they are not. The batteries are a few years old and, depending on their history, may not be in the best shape. A capacity test would tell, but they could be replaced at their age. I often recommend getting them from Walmart, not that Walmart batteries are better than any part store batteries, but they are about the same quality while less expensive, and I've had good life out of them. Around here, throw a stone and hit a Walmart.

The type of positive clamp on the passenger battery is not a good design, but it's often used due to the shortness of the starter cable. Not sure if you are willing for the expense of new cables, which may also depend on your ability to clean everything up and possibly install new lugs.



So based on what I am understanding, I should have continuity between the 2 positive terminals and both batteries should theoretically read the same voltage even if one is bad. I just tested and could not get continuity between them with my multimeter which would indicate a bad crossover, at a minimum. Is this correct thinking?

There should be no difference in voltage between the two battery positive terminals and a common ground. To test continuity between the two terminals, they should be disconnected from the battery terminals. I don't know if that's how you did that; we don't know each other well.

All those terminal connections should be cleaned; every lug, terminal, and post. Considering the condition of all that from the last owner, the grounds should probably be cleaned as well. I've got a video on that.

You Tube

To clean the bared cable wire, you can let the end sit in white vinegar for some time, wash it, then dunk it in a baking soda solution to neutralize. There are electrical cleaners out there you can also buy.

​​​​​​​Back to yard work for a while.

 

I think I agree. I am going to go get 2 AGM batteries from Walmart and clean or replace as many cables as I can.

 

Thanks runthatjunk. I am not against putting money in where it will be beneficial. I am going to clean or replace whatever I can cable wise and put in 2 batteries and see where that gets me.

 

Great video Jack. I am going to clean up all that I can and maybe replace a couple where I can. Definitely going with the walmarts. Their AGM is $169.

 

Those I haven't run, but I'd like to. They have not been available in my area.

 

It also looks like Tractor Supply might be a good source for some lower gauge battery cables. Stuff I didn't see at the other stores.