2000 3500 van gauge problems

[Craigart14]

2000 Dodge RAM 3500. On startup, stalls but will not idle. With a little gas, it runs fine, but I have to brake with the left foot because it stalls if I take my right foot off the gas.

Oil gauge and fuel gauge max out, but charge gauge drops to zero. After driving a while, for some unknown reason, gauges return to normal, showing good oil pressure, 14-16 volts charge, and correct fuel amount.

Then it quit on the highway after 1000 miles. Battery ($180 Interstate only three months old) was dead, so dead the local Walmart said it couldn't be charged. So new battery. Nearby AAA rated shop replaced the coil, telling me that the "old" coil actually looked pretty new, but was cracked and arcing.

Ran OK for a couple of hundred miles, though still with gauge fluctuations.
Then quit. I put in a new crank sensor. Another shop replaced the coil again and put in new distributor cap and rotor. Seemed to run fine, but a few days later the battery was dead again. Following online advice, I installed an external voltage regulator, jump started the engine, and all seemed well: smooth running, no stalling, normal gauge readings. Unplugged the regulator to keep if from draining the battery, then plugged it in and the gauges went haywire again. Battery is dead again despite 24 hours on a Battery Tender.

I would connect the regulator to the fuse box so turning off the ignition would break the circuit, but I can't figure out how to do that with square fuses. No add a fuse for that. So I think I will wire a switch to the dash so I can shut off the regulator manually.

Any ideas why it stalls? Or why batteries keep going dead?

All suggestions appreciated.

 

[dudeman2009]

Stalling I dont know why it does that after a severely discharged battery. Mine does that and thats even with a new engine and PCM. So its gotta be something that just happens to all of them when the PCM loses its settings, or another component that isn't replaced when putting another engine in (no sensor swaps, sensors are all new) with a new PCM.

As for the discharging, you've got some serious draw, to determine what it is though will help if you know what voltage the battery is at. Electronics will rarely draw it down below 6V as thats when most of the ICs stop working. Below 4-5V and you're looking at a passive load drawing it down, such as corrosion or a light. Check your glovebox to make sure the light is going off. I was pissed off for three days, each morning waking up to a dead truck, only to find out one night that the glovebox was lit up while closed.

 

[Craigart14]

Stalling I dont know why it does that after a severely discharged battery. Mine does that and thats even with a new engine and PCM. So its gotta be something that just happens to all of them when the PCM loses its settings, or another component that isn't replaced when putting another engine in (no sensor swaps, sensors are all new) with a new PCM.

As for the discharging, you've got some serious draw, to determine what it is though will help if you know what voltage the battery is at. Electronics will rarely draw it down below 6V as thats when most of the ICs stop working. Below 4-5V and you're looking at a passive load drawing it down, such as corrosion or a light. Check your glovebox to make sure the light is going off. I was pissed off for three days, each morning waking up to a dead truck, only to find out one night that the glovebox was lit up while closed.

Voltage across the battery with engine off is 11.8. So I put in a new alternator and wired it through the external voltage regulator. Voltage across the battery read 15.8. Is that too high? Or is the regulator compensating for a very weak--many would say dead--battery?

Even with the engine running and charging at 15.8 volts, oil pressure gauge and fuel gauge max out, charging gauge reads nil. This is a conversion van, so the alternator also charges two house batteries. I will try disconnecting the house connections to see if anything changes.

Craig

 

[dudeman2009]

15.8 is too high for most things. I'd never want to see charging voltage above 15v on active electronics. Some battery chargers will push 16V but thats usually alright if everything is off or sleeping.

15.8v if not damaging anything will cook that battery, it will gas off and go bad if it isnt already.

The highest i'd consider normal is 14.8v.

Seeing as its a conversion there is often times included with a TV or rear radio, an amplifier either for the TV or radio that will draw anywhere from 50mA to 1A. You'll want to check parasitic draw with a multimeter. There are two ways to do that, either with a shunt or just by having 3 hands.

To check the battery, take it to a Sears auto, or autozone and they will test it for free if the battery is out of the vehicle.

As for the gauges, a cluster self test will tell you if there is an issue with the gauges themselves or if its getting bogus data.

 

[Craigart14]

15.8 is too high for most things. I'd never want to see charging voltage above 15v on active electronics. Some battery chargers will push 16V but thats usually alright if everything is off or sleeping.

15.8v if not damaging anything will cook that battery, it will gas off and go bad if it isnt already.

The highest i'd consider normal is 14.8v.

Seeing as its a conversion there is often times included with a TV or rear radio, an amplifier either for the TV or radio that will draw anywhere from 50mA to 1A. You'll want to check parasitic draw with a multimeter. There are two ways to do that, either with a shunt or just by having 3 hands.

To check the battery, take it to a Sears auto, or autozone and they will test it for free if the battery is out of the vehicle.

As for the gauges, a cluster self test will tell you if there is an issue with the gauges themselves or if its getting bogus data.

Thanks. Drove 300 miles or so today. Van started this morning after a night connected to a battery tender, but pulled its usual stalling trick. Discovered that if you put an empty soda can under the gas pedal and a brick on top, you can press the gas pedal until you get the rpms you want, and the engine will keep running while you test things.

So after half an hour or so of two-foot driving with fuel and oil pressure gauges maxed out and battery gauge at zero volts, van suddenly began running better, no stumbling or stalling, and gauges went to normal readings, but the battery gauge kept rising, maxing out at 18 volts at 55-60 mph. When I stopped to put the multimeter on the battery, charging dropped to about 14 volts at idle. Driving again, back up to max. Sometimes it would settle into a normal range and the check gauges light would go off, but it would continue to settle down to zero and the check gauges light would come on. Then it would rise slowly to max.

I'm thinking the alternator was working extra hard because this vehicle has two "house" batteries that are also charged by the alternator and which were pretty dead yesterday. Tomorrow I will disconnect them to see what that does. Also, the regulator I wired in externally is a cheapo Chinese part, so I might try to snag a Mopar regulator.

Drove all afternoon with no accessories on except the headlights, trailer lights, and heater. Still puzzled.

Craig

 

[dudeman2009]

Try getting a quality voltage regulator, though the PCM has a built in regulator and if thats also connected things are going to go haywire.

Also try disconnecting the house batteries, they can cause weird things, not usually these types of things but anything is possible with aftermarket setups.

 

[Craigart14]

Try getting a quality voltage regulator, though the PCM has a built in regulator and if thats also connected things are going to go haywire.

Also try disconnecting the house batteries, they can cause weird things, not usually these types of things but anything is possible with aftermarket setups.

Ran fine yesterday except for odd gauge readings, particularly when the charge gauge rose to max then dropped to zero. Motor never missed a beat. Started and idled fine this morning, so I let it run a while. Then it quit. No start. Thought it was out of gas so added five gals. It kept cranking well but didn't fire. Then it caught and ran then stopped. Pulled key dance codes, all five mentioned voltage, so put in new regulator. Codes gone, still cranks but won't fire. Stumped. Should i fetch more gas?

 

[Craigart14]

Try getting a quality voltage regulator, though the PCM has a built in regulator and if thats also connected things are going to go haywire.

Also try disconnecting the house batteries, they can cause weird things, not usually these types of things but anything is possible with aftermarket setups.

Disconnected house batts, no change. Van started fine yesterday, idled smoothly, then stalled, wouldn't restart though cranking normally. Key dance threw 5 codes, all about voltage. New regulator got rid of the codes, but engine still won't fire.

Could a bad regulator fry an ignition coil?

 

[Craigart14]

Try getting a quality voltage regulator, though the PCM has a built in regulator and if thats also connected things are going to go haywire.

Also try disconnecting the house batteries, they can cause weird things, not usually these types of things but anything is possible with aftermarket setups.

Built in regulator is disabled. What could a bad regulator fry? Battery now shows 12.5 v engine off.

 

[Craigart14]

Codes are: p1682, charge voltage low
P1594, charge voltage high
P0622, generator control field circuit malfunction
P1281, engine temp low
P0132, O2 sensor circuit high voltage bank 1

These are the codes the last time the engine ran. They were wiped when I installed the new regulator. Could any of them cause a no start?

 

[dudeman2009]

At this point i'd be checking grounds to make sure they are all clean and tight. You have some strange issue going on here. Cranking without firing may be a coincidence.

Are you getting spark? Fuel? air?