Last post on Nov 13, 2013 at 2:30 PM
You are in the Dodge Dakota-2010 and older
What is this discussion about?
Dodge Dakota, Electrical, Truck
#229 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [twizted]
Sep 07, 2008 (12:22 pm)
Well, if you disconnected the alternator and the engine quit, I'd start suspecting a bad battery. If the battery was producing at least10.5 volts or so, the engine should still be running. Actually, if seen engines run on lower voltage battery voltage than that.
As far as the possibility of an unnatural drain, you need to measure the current flow (in series with the battery) when the ignition is off. Because there are some electrical circuits activated at all times (ie: computer, electronic clock, radio memory, etc.), there will be a slight but measurable current drain when the ignition switch is in the off position. Mopar computers draw about 10 to 20 milliamperes. I can't remember off hand what the clock draws, but anything over 100 milliamps should be suspect.
#230 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [dustyk]
Sep 08, 2008 (12:11 pm)
I think you might be right about the battery. It's only running about 8-9 V, but it's RUNNING. Go figure.
What I don't understand, though, is why I would get an engine cutoff from disconnecting a running engine from the battery. Isn't the alternator supposed to be able to maintain the engine running, without the loop of the battery? I thought the litmus test for an alternator was to pop the battery cable, and see if it killed the engine?
/doing it wrong, apparently.
Advice welcome and DEEPLY APPRECIATED!!!
#231 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [twizted]
Sep 08, 2008 (3:28 pm)
On a modern engine with electronic fuel injection,electric fuel pump,electronic-shifted automatic Xmissin and onboard computer(s) controlling it all... it is an EXTREMELY BAD IDEA to dicsonnect battery while engine is running. The resultant voltage spike could cause irreversable harm to the electrical system. Disconnecting the battery with engine running could cause instant self-destruction of the alternator-control circuits.
I am formally trained in electronics and could design an automobile electrical system, From that perspective, I can tell you that a known-good battery must be connected because it is an intrinsic part of the overall electrical system. Without a battery in the circuit, the alternator could cause spikes over 20 volts. Dont forget that not only does the ENGINE have a computer .... the automatc Xmission also has its own computer. The entire dashboard is fed with a 'databuss' and is-itself a client computer. The CTM (Central Timer Module) is also a client computer in the electrical system.
The damage to the onbaord computer(s) may not be redally apparent. You may encounter all kinds of electircal issues in the future.
Specific to Dodge Dakota, It is a KNOWN FACT that a weak battery can cause all kinds of problems such as erratic idle, odd shifting, intermittant-wiper strangeness...etc.
#232 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [twizted]
Sep 08, 2008 (3:35 pm)
To properly troubleshoot a discharging battery - With engine OFF, use ammeter and pull fuses to isolate the problem-circuit. Once you locate the circuit, it is usually trival to isolate the problem and resolve it.
#233 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [bpeebles]
Sep 11, 2008 (7:09 pm)
Bpeebles is correct. Switch in or out of the battery or alternator could produce spikes that can cause damage to some electrical components.
However, if you disconnected the alternator and the engine couldn't run on the battery, you do not have enough battery current to sustain the engine. The engine should run on a fully charged battery without a charging circuit. In my experience things get iffy around 10.0 volts, but I've seen some run on a battery with as little as 9.5 volts at terminal, at load.
If you're measuring around 8.0 volts no load your battery is way under charged. More likely, however, the battery has had it especially if its a factory unit. The batteries in the 2000-2002's were notable for producing weird symptoms.
I had a friend who's Dakota windshield wipers would make an occasional one-pulse swipe and then stop on the glass without going to their parked position until the ignition switch was switch off, then back on. This problem puzzled he and I and the dealer for 4 months. It was after he told me that he had to reset the clock a few times that I suspected the battery. Then one day it wouldn't take a charge. He limped home thinking he lost the alternator or computer, but after replacing the battery all was well. The wiper problem has never returned.
If you've got the factory battery in that 2002, it might just be a good idea to replace it anyways.
#234 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [dustyk]
Sep 12, 2008 (7:02 am)
Actually, I have thought of the battery, but the circumstance which causes it to discharge is so... spotty. I have a short drive to a family member's home, about 2 miles, and I can drive that back and forth without issue. It's when it runs for more than 5 minutes I lose battery power, and end up limping to wherever I'm going and just pointing it downhill, not always possible.
I will probably try bpeebles strategy, too, and isolate out the problem circuit. My more immediate concern was that I had a fresh battery in it, borrowed from a buddy's truck, and I pulled the cable lead for the battery on a NEW alternator, and it still died. I'm frankly open to suggestions on why this might be. Is it because the circuit is broken, and the alternator cannot complete the charge-through of the engine to sustain combustion?
Not as bright about this engine stuff as I'd like to be.
#235 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [twizted]
Sep 13, 2008 (3:58 pm)
twizted said: I pulled the cable lead for the battery on a NEW alternator, and it still died. I'm frankly open to suggestions on why this might be.
Again - The battery MUST be in the circuit for things to work. Dont forget... the voltage-regulator is IN THE COMPUTER. (not in the alternator like other vehicles)
Do not concern yourself any longer with what happened when you disconnected the battery with engine running... it was an invalid test. (Lets just hope you did not damage somthing in the electrical system)
An easy way to test your alternator while is to go to WallyMart and pick up a digital voltmeter which plugs into the ciggerette-lighter socket. It is a pretty slick little tool to have in your toolbox. Anything less than 13 volts with engine running should be considerd suspect.
#236 of 509 Re: 1995 Dodge Dakota 2wd 5sp Manual, electrical gremlin [bpeebles]
Sep 13, 2008 (4:09 pm)
Noted. I'll pick one up when I grab the battery, prolly also from wallyworld.
And you're right, I should have thought of that, Dodge being the electro-centric system it is, that the issue would not be tested from that, but it's... been a long time since I owned one. Over a dozen years.
#237 of 509 88 dakota intermitant no start
Sep 16, 2008 (4:19 am)
My 88 Dakota at times will not start. I can drive it someplace, shut it off and it may or may not restart. After a period of time (days or hours) it will start. I had it towed to a mechanic and when it got there it started. They couldn't do anything to make it not start. When I got it home it wouldn't start. Later in the week it started. It turns over fine and runs great when it is running.
#238 of 509 Re: 88 dakota intermitant no start [dusty9]
Sep 16, 2008 (4:56 pm)
More details please....when it does not start:
*) does the starter crank the engine?
*)if so, does the engine fire at all?
*)Can you smell raw gasoline at the tailpipe?