I will be honest, I don't like Chrysler at all. From the oil bricked engines used in Dodge Intrepids to not putting a handy little thing called Brake Shift Interlock on some vans, also known as "Let's not run over grandma, little Elly" due to it adding a mere 50 cents more to the cost of the vehicle

So let's take a look at the dodge Dakota. It's a sporty looking truck, with more cab room then the ranger, but as usual with Chrysler's Engineering Team churning out worse pos's then a Russian's Auto Engineering team tripped out on LSD. Just in case you did not know, Russian cars have looked the same since about 1987.

However Chrysler did sometimes complete the phase in their engineering genius called "doing chit right", making cars like the Lebaron.

Going back to the Dakota, it's electrical system is nothing but a few loose nuts short of getting a big FAIL stamped on it.

Here is one for starters, the airbag is fused on the same circuit as the taillights! Unlike most cars that have a separate fuse for the airbag, Chrysler never even thought that someday, somebody would actually put a trailer on this rolling deathwagon. As you may know, more light=more amps, so the addition of trailer lights blows the factory amp rated fuse for the airbag and taillights.

So let's move on to the problem that required this thread to even be written.

My Dad [unfortunately] owns, or technically the truck owns him, since he has wasted hundreds of dollars due to Chrysler having idiots for engineers, a 1995 Dodge Dakota Sport. Sport, a word which here means, a red stripe on the side of it, and a cool looking emblem.

One day while on a fishing trip, he returns to his truck to find that the fuel pump decided to say "Screw You!" and quit on him. Luckily he was only 2 miles from home, and not 200.

$160 and a new fuel pump later,he is, and to quote Willie Nelson, "On the road again".

I took the fuel pump apart, and come to find out it had a bad spot in the commutator. Hook it up to 12 volts, it would work, hook it up to 12 volts again, it would not work, but give it a little spin and it's off and running.

This stroke of luck lasted about 3 days, on Sunday, which will be referred to from here on out as "All Hell Breaks Loose Day".


The truck quits yet again, it won't turn over. After checking the obvious, and removing the hose to the injector, it's not getting any fuel.

Brand new pump died? Not so fast. The ASD or automatic shutdown Relay was getting hot. The fuse kept blowing.

We took a spare 50 amp fuse, shoved it in place of where a 30 amp fuse went, and limped home.

I know putting a 50 amp fuse in place of a 30 is the equivalent of being a certified dumbass. However being 20 miles from the closet place that sells fuses, walking was not an option.

So we get home, and do a through examination of the wiring harnesses.

Nothing seemed bad, no broken insulation, no melted insulation, a rat did not make it's home out of wires.

So what could of blown the fuse?

Time to crack open the wiring diagram.

The ASD Relay powers the fuel pump, ignition coil, oxygen sensor, fuel injector(s) and part of the computer.

Fuel pump is new, so I doubt that would cause the issue.

The ignition coil was swapped out, luckily we had a spare.

The injector wires were checked and were cool as a cucumber when the 30 amp ASD fuse blew.

So after checking everything else, we decided to let it be for now. The 50 amp fuse was keeping everything running.

Until 2 days later when IT blew.

So far the problem only happens when starting. All wires were checked, none seemed hot.

So another 50 amp fuse was stuck in. My dad got in the truck and tried to start it.

The 50 amp fuse did not blow, in about a split second, the wire inside the fuse melted, then it blew.

Whatever it was, was a dead short. To melt a 50 amp fuse takes quite a bit of resistance.

The truck gets pulled by my dad's neighbor. My dad swears up and down it must be that new fuel pump. My dad is smart but not a pro at electrical systems. In an hour he has the bed off, and the old fuel pump out. He swaps it for another one. The truck works fine.

I kept my mouth shut waiting on a huge "I TOLD YOU SO!", luckily one was not issued.

So we drive to town, the entire time my dad has a big **** eating grin on his face, until it happens yet again!

Remember how I said the fuse only blew during starting? Well while strolling along the highway at 55 miles an hour, the truck just dies, like someone turned the key off.

We open the hood to see the 50 amp fuse smoldering and obviously blown.

Since these fuses are called "fusible links" a term that the auto industry came up with to trick people into blowing $4 each for these.

I told him to unplug the oxygen sensor, pop another fuse in, and see what happens.

Well it started right back up!

So now I have some questions.

1. Could a failed Oxy Sensor blow a fuse?
2. Since this problem is so intermittent, what else could be the culprit? The truck was given a through inspection for bad wiring.

 

HOLY ****!! Do you want to tell us about how your dog takes a **** too! LOL Sorry that is the longest useless story ever. All you needed was a few sentences.

First Dodge is not the only vehicle manufacture to cut corners. THEY ALL DO! Ford with the Pinto, the gas tank would explode. One of the vans rear axle/tube would completely bend into a V with normal driving. And lets not forget the Firestone incidents, where they were to cheap to afford good tires. And Chevy ect.

Yes they all cut corners. ALL!! If you save .50 cents per truck and you make 600,000 of the exact truck that is $300,000 you just saved! Very simple math!!

Remember they are a corporations. ALL corporations no matter what they make, are in it to make money. Or else they wouldn't be around.


Now to your problem. You never specified WHAT system the fuse went to.

THIS IS YOUR SOLUTION!! Follow that wire for that fuse down, it will eventually go to the battery, and to what ever it is powering. Once you trace it far enough you will find your problem. And I mean untape it ect. PHYSICALLY separate it from the rest.

THERE IS A REASON YOU ARE BLOWING FUSES! The fuse is telling you something is shorting in the circuit.

1. If an O2 sensor is bad it will not cause blowing fuses. But if the wires are cut and shorting it can.

2. OBVIOUSLY the truck was not fully checked for bad wiring, since your still blowing fuses. Did you PHYSICALLY separate the blown fuse wires from the rest all the way to the battery and all the way to what ever it is powering?

Did you bust out a Mulitmeter and check continuity on ALL wires to the correct plugs?

Next is the ASD does not power the fuel pump and I believe it doesn't power the O2 sensor, but I'm not sure on that one. And doesn't power the computer, it just takes an input from it which tells it the key is in ON.
The Auto Shut Down relay provides a common positive for the Fuel Injectors and Coil. That is why it is called ASD because it shuts down the truck when it is not energized. The negative of the Fuel Injectors and Coil is provided by the computer.

Possible problem: The Fuel pump and ASD relays share the same positive and negative splices. These splices are a common point of failer, due to the solder corroding. Typically it will just cause a shut down, but it could short against another wire next to it. The FAQ has a good write up on it with pictures. The FAQ is in this section, just a few posts above this one.

Next is 95 is a 1st Generation Dakota. I moved this post into the correct sub-forum.

 

The power distribution box has a cutout for a fuel pump relay. However there is not one.

According to the diagram from the Chilton manual, it also confirms that this particular Dakota did not have a separate fuel pump relay.

Also both the web and the book confirm that the o2 sensor's heater is powered by the ASD relay.

The problem is also unique because the truck will run when parked, however the next time it's started, fuse blows.

This occasion happened 3 times. The 4th time it occurred while running.

I don't think it could be in the wiring do to the fact that it ran when parked. If wiring was bad, you would think the truck hitting a bump, or being jostled around by potholes would short it out again.

No kind of sudden or harsh movement was done to the truck before the fuse blew again.

You would think if the wiring was bad, movement to the truck would short it out.

As a matter of fact, during the phase of blowing out 3 fuses, the truck was shook up and down, and the wiring was inspected for warm spots, and the wiring harness was moved around, however fuses kept blowing.

Once the O2 sensor was unplugged, and a new fuse inserted, the truck did not blow any more fuses.

The O2 Sensor itself had over 150,000 miles on it. It also has a heater element inside of it. I would think that if the heater got a piece of metal in it, it could short out the fuse.

I think the metal piece is loose, due to the fact it is not a constant problem.

Tomorrow, me and my dad are going to open the wiring harnesses on both sides of the engine, and go through it, also checking splices.

I will keep everyone informed on how this goes.

 

Yea, the 2.5L I4 trucks, per the 1995 service manual, didn't make use of the Fuel Pump Relay.

Something tells me you already answered your own question.

 

Techfizzle, I appreciate the detailed description of your troubleshooting efforts. Same problem for us with 95' Dakota 2.5liter engine. I've read several messages on repeatedly blown ASD fuses. Unfortunately no one has listed what their solution was. I would guess they may all be related, although it looks like several systems are associated and may cause this problem. I too have moved the harness during good run time and found no shorting in wiring. Very intermittant sometimes while driving, sometimes while starting up. Haven't replaced O2 yet, was this your final fix? Thanks for any help you may provide.