My neighbor has a 1998 Ram 1500 with a 5.2 motor. I was helping him troubleshoot it yesterday and thought I'd ask here.

It turns over fine but doesn't start. The gas gauge quit working at the time the problem arose. It's got a full tank but the gauge doesn't register at all. Just wondering if it could be a blown fuse, a bad fuel pump, relay etc. I think there's a connection between the gauge stopping working and it not starting. I'm no mechanic that's for sure so I thought I'd ask here.

It worked fine when he parked it, the next day it didn't fire at all. Turns over great.

It could be a blown fuse. It could also be the computer of the truck as well. My son's first car was a beater Chrysler Sebring. He was set to get a lot better car, and then he thought he was God's gift to the universe, so he got the POS Sebring. Anyways, his car did the same thing you are describing, and after trouble shooting it, we found a blow fuse.

I believe that the fuel sending unit is part of the pump. It could be a blown fuse or possibly the whole unit quit working. The owners manual will show which fuse controls it. You can also find it onlline if there's no manual.
Fuses don't just blow on their own. Something has to cause it and finding that can be a trick.

Fuel pump has stopped working, beat on bottom of tank. Sometimes this will make it start working. It it runs, its temporary, get a new pump pronto.

Try pouring a bit of gas in carb, see if it runs at all.

It could very well be a bad fuel pump, as the pump/fuel level sending unit are housed together in an assembly about the size of a 2-liter bottle that sits in the top of the fuel tank. I had to replace mine in my 1995 (same series as the 1998) due to the same issue. They are not expensive (around $100 if I recall correctly), but a PITA to replace, unless you have 4 football players. Disconnect all the wiring from underneath the bed of the truck, remove 4 bolts holding the bed down to the frame, and simply pick the bed up off the frame and sit it aside. You can then remove the fuel pump unit from the top of the tank. I had 3 powerlifting friends from the YMCA come over and help me lift it off once I had everything disconnected, it took us all of 15 minutes to lift it up, removed the fuel pump/fuel gauge sending unit from the top of the tank, and sit the cargo bed back on. They left and I finished buttoning things back up.

If you do that, keep your face away from the carb when you crank it. A backfire can take your face off.

crawl under the truck next to the gas tank, if you don't hear the pump come on when you turn the key forward your pump is bad, it could be a fuse, relay so check those first.

98 is injected, no carb.

You can still pour a bit of gas in it ???

Will do fuel pump sound check when I go over, check fuses and other

Thanks gents.

I can't hear good enough to tell if an in tank fuel pump is running or not so I bought a fuel pressure gauge. It was cheap and you can also tell of you have low fuel pressure which will cause problems on injected engines.

Will it fire on ether? If so, it's a fuel problem. If not, it's likely an electrical problem.

I once had a Dakota that just quit running one day. Drug it to a mechanic. He searched and searched for the problem. Finally, he removed an electronic part he called a "Halifax" mounted on the front of the firewall. Replaced it and it ran like a top. I don't know what the correct name of the part is, coil maybe?

pretty sure they had done away with throttle body injection by 98, you could spray starting fluid into the air intake but i don't think i'd want to try that with gas,

atta gas.

If the truck wont start or fire with abit of fuel sprayed in the intake...check the timing chain hasn't jumped some teeth.

Bad fuel pump or bad connection to the fuel pump would be my guess from past experience.

Honestly, my automobile problems became way less frequent once I decided to stop buying Chrysler problems; and to a lesser degree, Chevrolets.

i've replaced two fuel pumps and two rack n pinions in my dads Chevy, stuff will wear out on all makes.

Tried the ether thing yesterday and it didn't fire.

I haven't been there yet today and he hasn't worked on it yet either. I'm thinking fuel pump at this point but it's less than a year old and quit all at once. Strange.

Could be electrical.

Like I said, I'm a terrible mechanic. 😀

also had the rear end apart twice to replace bearings. why would anyone design a differential with c clips.

I had a beautiful Z71. Cherry! After I replaced the heads, front differential, transfer case, and several other lesser problems, I finally sold it. Like the dumbazz I am, I let my younger son talk me into buying him another Z71. So far, all I've done is work on it too.

We also have a Ford, Honda, and 2 Toyotas. All we do is put gas in them and drive.

There isn't enough bandwidth to describe all the problems I ad with the last two Dodges I've owned. I used to be a big Mopar fan.

I know other have had differing experiences, but you only let a snake bite you so many times before you part ways with him.

If you look up dodge in the dictionary its says.....to avoid or evade

Had very similar issues with my '01 Ram.
Dodge has a known problem, at least from the late '90s to the early 2000's with the PCM (computer). From your description it sounds exactly like what my Ram was doing.
At 161,000 miles failed late last summer. The engine would turn over fine, but (usually) would not even try to start. Sometimes it would run for a second or two, sometimes it would run until it got up to temp then die. The gauges became inoperative. I finally broke down and took it to the local Dodge dealer to have them fix it. Two hundred dollars later they told me they couldn't find a definite cause, but it may be the PCM module. They wanted $700 to replace it with a reman unit (new units no longer available) and another $125 to flash the unit with the latest firmware. They also stated that it was a 2 hour job the replace the computer--pure BS. It takes less than ten minutes from start to finish.
I did an internet search and found several companies that sell remanufactured units that come flashed with the latest firmware for under $300 with a lifetime guarantee. I went with a unit from SOLO Auto Electronics.
The first unit failed on start up. SOLO replaced it with another unit. It ran fine for about 10 minutes then it, too, failed. SOLO replaced it immediately. Third unit failed with in about 50 miles of driving. SOLO also replaced this one immediately. The fourth unit lasted for 238 miles. I just put the fifth unit in last week--so far it's working.
My daughter has an '05 Dodge that had the same symptoms that also turned out to be a PCM failure. So far, after about 12,000 miles, hers seem to be running fine with the first unit she got from SOLO.
My guess is that's probably the cause with your neighbors Ram, the symptoms sound identical.

Aftermarket fuel pump out of China?

I'm not sure, probably.

I doubt I'll get over there today.

To be a bit more specific, you should:

Make sure all 6 (3.9L V6) or all 8 cylinders are getting spark with a spark tester.
If spark was present in all of the cylinders, then this result tells you several very important things:
The distributor cap, distributor rotor, and the spark plug wires are OK.
The ignition coil is OK and functioning correctly.
The crankshaft (crank) position sensor is functioning correctly.
The Auto Shut Down (ASD) relay, which powers the ignition coil, is good.

NOTE: One of the most common failures on these Dodge vehicles is a bad crank sensor causing a no start condition. Since the crank sensor is at the heart of everything that is involved with starting the vehicle. When the crank sensor has failed you'll see the following specific symptoms:

The PCM will not activate the fuel injectors.
The PCM will not activate the ASD (Auto Shut Down relay).
If the ASD relay does not activate, the ignition coil will not get power.
If the ASD relay does not activate, the fuel pump relay will not activate.

More here if you care to puruse. Code scan would also help isolate.
https://troubleshootmyvehicle.com/chrysler/3.9L-5.2L-5.9L/how-to-test-a-no-start-2

Did anyone check it for codes? I had a 93 Dakota that stopped dead in its tracks when an O2 sensor failed. It tripped an auto shutdown relay and would crank but not fire. I also had a Plymouth Breeze that had the fuel pump go bad. That repair would have cost more than the car was worth. It was 20 years old.

My 2001 5.9 did the same thing, it was the pump. I figured it out by cranking it and pouring a small amount of gas down the fuel injector. It gave a very brief attempt at starting (just a sputter). So I knew that the electronics were functioning. There is a fuel pump relay that can prevent currant from getting to the plugs that can also cause that problem.

You can accomplish the same thing with a lot less hassle by squirting some starter fluid directly into the air intake. If it starts, then look to the pump as the issue.
Crank and/or cam sensors may also be the cause.

Actually the easiest way to test for injector bleed down, poor pump performance is to put a pressure gauge on the test port at the inlet of the fuel rail, usually a Schrader valve. Hook it up, turn on the ignition and it should pump up and usually hold 75 psi on throttle body and 90-95 on injectors.

My guess would be bad ignition switch. I have seen other trucks crank, but no power to the dash, turned out to be the ignition.

I would get it running and unload it.

So would a tank of gas.