Truck won't start

If the filter you had off is the one between the fuel tank and lift pump, you will not see fuel pumping out of it when you crank it.

If you pumped the hand primer with any filters removed, it won't stay stiff as you're either pump fuel out on the ground or sucking air.

Lets go back to the batteries. Sounds like it struggles to crank. Since its got new batteries, I'd be checking all the cables and connections between the batteries and starter, batteries and frame, and starter and engine/frame if it has any. 4 brand new batteries should spin that engine over almost effortlessly even at temperatures slightly below freezing.

 

Those cable ends look a little nasty. The green corrosion is not good for power transfer. It will cause a voltage drop across it. Each voltage drop will result in less power to spin the engine over. It can also affect the voltage available to the ECM. Once you get sub-9 volts to the ECM its a crapshoot as to whether or not the ECM has enough power to operate the injector solenoids.

Even if cleaning all the cable ends/replacing any damaged or rotten cables doesn't fix the issue, it'd still be a good idea to get done for PM and peace of mind.

 

I'd definitely clean up the connections at the starter as well as where the grounds connect to the frame. I can't remember how Volvo connected their grounds but I was told some manufacturers used a star washer between the cable and frame rail that would cause issues once the rusted up a bit.

 

Do like @AModelCat advised. Electricity, especially DC, doesn't like resistance, that's why those cables are the size they are. That green corrosion in the upper left of your picture doesn't look good either. You might not be able to tell how far up inside the cable the corrosion goes. You might need to replace it. If you replace the cables, don't skimp on the quality or gauge. With 4 new batts, that should spin easy like he said.

I'd take each cable off, inspect for corrosion, and put the ends to a wire wheel= shiny brass and put back on coated with copper conductive never seize. Wire wheel to the starter and frame connections also. Ensure all your electrical connections are clean & shiny. Don't overlook the ground cables either, and make sure you have a clean ground connection between the engine, frame, and batteries.

If after doing all that doesn't solve it, and I believe it likely will, you may have a starter on its way out.

 

Do the dash lights ( check engine etc) come on, with key in the on position? If not the 2 little wires for ecm are suspect. Mine has an in-line 5 amp fuse, on little hot wire to the ecm. Won’t start if it’s blown. Have you tried a little shot of ether? Little bit won’t hurt it. I’m thinking maybe you lost prime changing filters. I forgot to turn my shutoff valve back on a few weeks back afterwards. Used a whole can of either, before I realized it. Lol. Not the first time I’ve made that mistake.

 

Yeah if it’s got a primer pump, that’s what they’re supposed to do. Usually if ecm isn’t getting power, it will run on ether,or act like it wants to run. Check for dash lights, with key in run position, they should light up in “ test “ mode. No lights, no ecm power. Bad fuse wire or connections( frame ground) as mentioned. 55 degrees is plenty warm, shouldn’t have been gelled at all.