Good Morning/Afternoon Dakota Owners-

So I have a new-to-me 2000 Dakota QuadCab, 2WD, 3.9L, NV3500 that I just had to swap a knocking motor out of. We got everything buttoned up, and I went to connect the battery and I accidentally grounded the alternator charging cable. This of course blew the alternator fuse (140 Amp guy). I didn't notice it and the truck would turn over for about a second when trying to start, but wouldn't roll all the way over. I got underneath and bridged the batt to the starter and was able to get the truck to start up (even though the starter wouldn't just stay cranking, it'd just go for a second or two).

We started to troubleshoot why the starter would only tick for a second, and that's when I noticed I had blown the fuse. We replaced the fuse and then we got absolutely NOTHING from the starter when we tried to start...not even the short click we were getting before. If I manually jump the starter relay the truck will fire right up and idle fine so I know the battery, soleniod, fuel pump, ignition, etc. are all working because the truck will run and drive.

I also checked jumping the neutral start switch at the clutch pedal to see if that's the issue, but nada. When I do turn it to start it does cut out the radio, etc. just like it would if it was starting, but no jump from the starter, just radio cutting out, and then coming back once I'm done turning the key.

Looking for some magic...Thanks all!


-DakotaDunn

 

So I did a little more troubleshooting yesterday and went through all the fuses and relays. All the fuses and all the relays all appear to be healthy (rung them out with the multi meter) and clicking happily. I noticed that when the key is in the on position all the relevant relays (primarily the fuel pump) come on and do their thing, but when I turn the key to "start" there is a clear power draw but no love on the starter relay. I know that relay works because I swapped it for the fuel pump relay, and they both work.

I am leaning either towards something in a "safety" lockout on startup that I can't see or a bad ignition switch? Any thoughts out there with those of you with more experience.

Thanks!


-DakotaDunn

 

With the starter relay out, monitor the control circuit. See if anything is actually trying to trigger the relay when you turn the key to start. Make sure you are getting good power for both the load, and control side. (Not sure exactly how it works on the dakotas, a wiring diagram would be REALLY helpful here. )

 

Thanks, I'll give that a shot. Here's the pin out for the ignition switch http://brianesser.com/wp-content/upl...hconnector.png I'm going to try replacing it just to see as they're pretty cheap. Just going to put my meter across the "start" and see if I'm getting power to it, not sure how to determine if I should be getting power to it. I don't want to be jumping over any safety interlocks just to get it to run. However, when I jump the relay manually, the engine runs normal and has all the signs of health. Any particular aspect of the control circuit that I should be looking at

 

Ok, found a wiring diagram. Circuit is dead simple.

Ignition switch supplies power to pin 86 at the starter relay, (also goes thru clutch safety switch) pin 85 goes directly to ground. So, when you turn the key to start, you should see 12 volts on pin 86. Pin 85 should be a constant ground.

 

Awesome! Thank you for the extra leg work. I'll poke at it this afternoon as see what I can see. I'm assuming that I should see the 12v @ the ignition switch to then pass to the pin @ 86? So I'll check that it's coming from there, and then I should be able to figure out where the circuit is failing.

 

According to theory, it's a yellow wire coming from the ignition switch, that changes to dark blue with yellow trace at connector 200. No clue where that connector is though.

 

Well I am stumped. Pulled out the multimeter and went across the ignition to ground and got voltage at all the places I expected, when I expected it, but still no going for the starter. I took apart the relay box and just made sure nothing was smoked or missing, and all looks good. The truck will still start and drive happily when I bypass the starter relay, so I'm quite certain that there is nothing wrong with sensors (like crank position, etc.) as I don't think it would run without them.

With the relays, are some of them switched on ground? The starter relay has 12v at one leg constantly, so I'm guessing the ground gets switched? Or to I potentially have something reversed somewhere and I'm feed hot to where a ground should be?

 

Well, this chump is now un-stumped. So, engine swap shenanigans that were self inflicted! I accidentally put the ground for the alternator harness in-line with the actual charging cable. That did two things simultaneously. 1. There was no ground being passed to the starter relay because it was connected to hot, not grounded. 2. Because it was connected to the alternator cable, it was putting a constant 12v to the relay on the ground side.

So I learned a bunch of great stuff in the process, and appreciate all the help, and we're back on the road!


-Josh

 

Awesome!!! Glad ya got it runnin'.