Hello,

I have a 95 Dakota, 318 5.2L with 5 speed. In recent weeks I've been having problems with the truck not starting up on the first try.

What happens: turn the key on the first try, you get lights coming on the dash, you hear the click of the fuel pump coming on, you hear one audible click when you turn the key. But no crank. Then it usually starts on the 2nd or 3rd try, sometimes like this morning it took four times.

One day last week the truck threw a code 46 on, which is charging system voltage is too high. I wasn't too surprised, as I noticed the dashboard volt gauge needle seemed up there a little higher than normal. Since then, I've been checking the battery with a voltmeter and I get about 12.6 volts on the battery, give or take, and it reads around 14.3 volts on the battery while the truck is running. This seems normal for the charging system, and verified this in my Haynes manual. I checked connections to the terminals, all tight. However there is some corrosion around the battery terminal clamp bolts, but nothing on the clamps or terminals themselves. Connections to the starter are tight. Voltage reading to starter is 12.6 when engine not running, around 9 volts when it is. I've checked connections to the alternator too, all tight. I've checked voltage readings from the alternator, and I've seen the same voltage readings of about 14.3v when running. So far the code 46 light has only come on once and it's been about a week now since it came on. It went back out after the truck was shut off and has stayed off since.

One last thing. I keep meaning to check this more, but usually the truck only does this when it's been sitting for a while. (At least an hour or more.) Once it starts up, you can shut it back off and start up on the first try every time. It has to sit for a while before the problem comes back. So I checked the voltage to the battery one morning and it was around 11.5 volts. As soon as I did the multiple turn-key start and got it going, I got the readings as in the previous paragraph above.

Oh I should add the battery is about 5-6 years old, Sears Die-Hard Gold. Early on when this problem came up, I checked the acid levels and they were all above the plates. Some were a little lower than others, so I topped off with some distilled water.

Sorry this is long, but I figure the more info I post, the better someone will have an idea of what's going on. Thanks!

 

To me it sounds like your loosing fuel pressure after it sits awhile and thats why it takes it longer to start than if it was just shut off and started back without sitting awhile. Aslong as the battery is turning he motor over as fast as normal after sitting then i dont see the battery being the problem. As far as the code for over charging you could have a voltage regulator going bad insi

 

Sorry my phone went stupid. You may have a voltage regulator going bad inside the alternator allowing the voltage to spike. You should have 13.2 or so at idle and 14.5 at higher rpms.

 

Thanks for the input. I don't think it would be a fuel problem because if it was it wouldg at least crank over and not start. The computer is what controls the voltage regulation, correct?

 

Sorry missed the no crank lol. I would start by checking the voltage at the solenoid on starter while your trying to start the engine. If it has 12 volts and doesn't turn over then you need a starter. If it doesn't have 12 volts you have a wiring issue. if theres no voltage then probably the switch. It will take 2 people to do that safely. The alternator has its own voltage regulator to keep the alternator from over charging. Im not sure but i dont think the pcm controls that.

 

Yes like said above at idle the voltage should only be 13 or so, 14 is to high for idle. The output is controlled by the PCM But if the diodes go out on the alternator the PCM can't control the output. Most autoparts stores will test the alternator and battery for free.

As for the no start, possibly a bad relay or bad ignition switch or the notorious splice. Possibly bad or dirty or loose connections to and from the battery and starter. Or just a bad starter/solenoid.

 

Thanks again. The connections all are tight, so unless wires are bad themselves. BTW it started right up the first time this morning. Sometimes it does. The infamous splice was fixed years ago, so it shouldn't be that. I suspect if the system is overcharging, it's probably the diodes in the alternator. It's the original alt. I have a spare PCM if I can just find it, I'll try that to rule it out by swapping. The starter has been replaced only once, so it could be going too. Some tests and maybe a trip to auto store for charging system tests may be in order...

 

i would check the alternantor as well that would be my first stop i was also thinking it can be a bad ground

 

Can the diodes be replaced in these alternators? I know many alternators don't have replaceable parts anymore. It goes bad, you buy a whole new unit.

By the way, being an intermittent problem makes it trickier. The last two days now it's been just fine. Still gotta track the issue(s) down, or I'm gonna find myself stranded at some point...

 

No these alternators can be rebuilt but to just replace a diode no. The diode is in the voltage regulator assembly and will need be replaced as a until. Your best bet is to either buy a new one or have yours rebuilt. Me personally i have all my starters and alternator's rebuilt. They last alot longer than a new or reman. They normally cost alot less than a new one also. As far as it being intermittent that sounds typical for a alternator that is on its last leg so to speak.