battery light is on?

How many miles on the van? If it's high, suspect worn brushes in the alternator. To determine that you'll need an inexpensive digital voltmeter. Measure the voltages on the two small wires on the back of the alternator. This must be done with the engine running, and the numbers we need are when the problem is occurring.

This guide will help us fix it

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Please run down this guide and report back. caradiodoc

got low voltage reading for my 2006 dodge grand caravan sxt swaped battery but still getting the same reading?

IF the voltage is low with the engine running, have the alternator checked. If it checkes good, have the fuseable link between the alt and battery checked.

2002 Dodge Caravan 6 cyl Automatic
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Hi my battery light comes on in a rain storm or when i drive thur water. What is causing this?

Check and or replace belt and tensioner

Thank you, I'll try that

'01 Dodge GC Sport 3.3 engine...Battery icon light came on; then systems began shutting off one-by-one...radio, heater fan; then warning lights and bells began to flash intermittently; wipers began operating (sluggishly) by themselves; yet the vehicle kept running.
Battery tested ok.
Bad Alternator?

Weather: snowy/ wet driving conditions.

Recharge the battery on a slow rate for an hour or two, then use an inexpensive digital voltmeter to measure its voltage. If it's near 12.6 volts, it is ok. Measure again with the engine running. It must be between 13.75 and 14.75 volts. If it is low, dig down to the back of the alternator and measure the two voltages on the two small wires that are plugged in or bolted to the back. The engine must be running for these tests.

One terminal will have full battery voltage. The second one should be less, but if you find 0 volts, the brushes are worn. They can often be replaced without removing the alternator from the engine.

caradiodoc

I had the alternator tested, it was operating normally. Technician suggested testing ECM. could that be the problem? Is it something I can replace myself?

I'd really want to know what those two voltages are on the back of the alternator before I headed for the least common cause, (and most expensive). If you can get to the connectors on the Engine Computer, (Electronic Control Module - ECM / Powertrain Control Module - PCM), you can take the important reading on the brown wire / gray stripe in pin 8 of connector 1 instead of standing on your head to reach behind the alternator. You will measure full battery voltage, 0 volts, or something between 4 and 11 volts. 4 - 11 volts means that part of the circuit is working properly.

caradiodoc

I have a 2000 dodge grand caravan sport 3.3L flex fuel. The battery light stays on I have replaced Atlernator and battery and I still have the same problem I have 12 volts to the alternator when the key is off. At the battery when the engine is running I get 13.6 and with everything turned on I get 12.9. Is there two fuse links that go to the PCM from the alternator to the PCM regulator. Or could it be the battery sensor under the battery. I had to have the PCM reporgamed due to it had locked up and would not pass safety inspection.

did you verify powers and grounds for the alternator>> basics first.

13.6 under a load is not bad at idle. should jump to 14 with 1500 rpm. check the fuses for the light.

what was the issue with the old alternator?? the pcm does control alt output.

Roy

Yes, I have 12V at alternator and I checked all ground cables. They where ok.

Hi guys. You need to check the voltage on the two small wires on the back of the alternator but that has to be done with the engine running. One must have full battery voltage. The other one must be less but not 0 volts. Holler back with those numbers.

On the small wires I get 9.5 at idlle and 12.5 at 1500 rpm the other wire I get no voltage reading.

so my wife was going on a trip and half way there the battery light lights up. she gets there after four days heads back stops at auto store they test battery say its 12.1 volts okay to drive! she starts van light is out she drives five minutes light comes on she almost makes it back it stalls at stoplight battery to low to start/run. gets a jump light is out she drives a mile to house lets it idle for twenty minutes shuts it off. i get there start it light is out i take it for drive stop a few places light never comes back on. she gets in it next day starts it and light is on. she drives a few errands with it on gets back home shuts it off. restarts it light is off. shuts it off restarts it light is on. i bought van eight months ago have had no problems. alternator does not look like its been replaced in a while looks like 135 amp model. i know the regulator is in the PTCM. i noticed when i was checking it out the battery light does not come on with 'key on' like all the other warning lights. darn warning lights are hard to see tucked under the small flap on top of dash. did not think to do a code read? probably will not get back to it until weekend sometime.

Can you see the wire colors? Less than battery voltage is normal on the dark green control wire but it must not be 0 volts. If that 9.5 / 12.5 volts is on that wire, that part of the system is working and you didn't make good contact with the probe on the other wire. It had to have full battery voltage for there to be anything on the one you found voltage.

If that 9.5 / 12.5 volts was on the dark green / orange wire, that is the 12 volt feed and what you found is too low. Since that circuit runs injectors and ignition coils and is obviously working, that leaves a corroded splice as the likely suspect.

I think the first scenario is the one that pertains to your van because to actually have 0 volts on the dark green control wire, that wire would have to be grounded or the brushes inside the alternator would have to be worn and open. Worn brushes are common but not on a replacement alternator unless you installed a used one. If that wire was grounded, the system would be charging wide open and you'd be having an overcharge condition. Either way, this would imply there are two different problems.

Assuming the first story is right and you found that voltage on the dark green wire, measure the voltage on the fat bolted-on output wire. If it's real high with the engine running, as in 16 or more volts, there's a break in that wire going to the battery. Look for a blown large bolted-in fuse under the hood. You will also find 0 volts there with the engine off.

If you find full battery voltage at the alternator output terminal all the time but it's not making it up to 13.75 to 14.75 volts when the engine is running, suspect a failed diode inside the alternator. That can be identified with a professional load test. Most of these were 90 amp units. With a failed diode you will lose two thirds of its capacity and only be able to get around 30 amps. That would explain why the system voltage was dropping to 12.9 volts with many things turned on. The alternator can't keep up. That low voltage will turn on the "battery" warning light. Most load testers also display a bar graph to show relative "ripple". Ripple will be very high with a bad diode.

All indication are you have a charging system problem. You need to have it tested while the light is on.

did test while light was out and it checked out fine 14.4 volts i may just replace alternator this weekend since i have extra one. kind of weird it works and does not work depending on what? i do not know. the regulator being external adds the possible problem of wires/connections issues.

It really does not do any good to test it when the light is not on. Intermittent problems are not unusual. Although the alternator is regulated by the PCM, it will normally set a code if there is an issue there.

yes another thing to do read codes and i am not sure the check engine light is functioning bulb may be out! that stupid dash system is hard to see!

they post other similar question i am reading them i know my van is similar to 1996 -2000 i think.

Electrical problem
2000 Dodge Caravan All Wheel Drive Automatic

Hello my 2000 dodge grand caravan. It started running funny while sitting in the driveway the battery light came on and the car died. I replaced the battery and the car started up but the battery light was still on. It had been making kind of a grinding noise by the belts. i don't know if it the alt or what????? the serpentine belt had come off twice before but is intact and spinning fine but thats where the noise is coming from. Don't have money to take it in please help!!!!

The battery light means the charging system has a problem, not the battery. First of all, use a digital voltmeter to measure the voltage across the two battery terminals while the engine is running. It must be between 13.75 and 14.75 volts. If it is below 13.5, it will not fully charge the battery while driving.

If you do find low voltage, the most common cause is worn brushes inside the alternator. They can be replaced, in some cases without removing the alternator from the engine. Also check that the pulley is actually spinning. Since it was making noise, the bearings could be seized. Usually the belt won't last very long when this happens, and it could be related to the belt coming off.

caradiodoc

Hi guys. I posted an answer to the other question. Worn brushes are a real common cause of intermittent operation. The assembly costs around ten bucks, and on some models can be replaced without removing the alternator from the engine. You might not find this at an auto parts store. Starter/generator re-builders will have the assembly.

[quote:bcb74b401d="caradiodoc"]The battery light means the charging system has a problem, not the battery. First of all, use a digital voltmeter to measure the voltage across the two battery terminals while the engine is running. It must be between 13.75 and 14.75 volts. If it is below 13.5, it will not fully charge the battery while driving.

If you do find low voltage, the most common cause is worn brushes inside the alternator. They can be replaced, in some cases without removing the alternator from the engine. Also check that the pulley is actually spinning. Since it was making noise, the bearings could be seized. Usually the belt won't last very long when this happens, and it could be related to the belt coming off.

caradiodoc[/quote:bcb74b401d]


Thank you very much for your help! How would i tell if its the alt? the belt spins so could the bearings still be seized?? Thank you!

yah i thought of that wife sent it to garage so hope she likes the BILL!!

well it was just th alternator and by the symptoms likely just worn out brushes got hit with 300+ bill!! i coulda did it for 40! so that wa lat friday THIS friday the BRAKES went OUT!!

The brakes are buddies with the charging system and wanted to show their support for the alternator!

rear steel lines rusted out. and thanks dodge for using unstandard FINE THREAD on 1 line and for the backwards mounted valve assembly combined almost guaranteeing a STRIPPED hole!

Yep quality engineering. Please let us know how it goes.

as temp fix i just capped the rear lines didnt even have to bleed the fronts!

That's not even a temporary fix. That's a rolling accident waiting to happen.

actually the hidden rusty lines were also a rolling accident as you say as my wife experienced loss of braking power when they leaked! think how many millions of drivers may be driving in the same condition!

Yes, and think of all the innocent people they may hurt because of their irresponsibility. That's why cars have bright red warning lights.

what i meant was there are rusting lines that have NOT leaked yet and so no indication is on the dash until suddenly they unexpectedly leak and lose braking power! even so i think its rare that this actually causes an accident! and when the lines are hidden from view i would say many inspections dont reveal any problems! but there is NO way to prvent this unless manufacturers use stainless brake lines! could even be GOV mandated!

This isn't a debate about how dangerous brake failures are. This is about the conscious decision to drive a vehicle on the highway knowing there are no rear brakes. That will land you in jail if anyone is hurt.
I don't intend to discuss this any further.

yes well it was an economically driven decision cant fix back brakes until money and time is available. cant go without use of vehicle until then.not having back brakes poses no great risk except in some once in a million set of circumstances. the added stopping power of rear drum brakes is negligible. the fronts are incapable of locking the wheels under normal conditions.

Keep in mind almost all minivans have split-diagonal brake systems that put one front brake and the opposite rear brake on the same hydraulic circuit. I wasn't following this discussion, but if you have a leak in both rear brake lines, you won't have any brakes. That gets to be real hard on shoe soles when trying to stop like Fred Flintstone had to do!

and wouldnt cha know a grinding noise happens soon after!! 1 inner pad has worn unevenly even though caliper guides move smoothly! and besides that the pads aint 6 months OLD!! sheesh another case of profit over quality!!