Boy do I have a good one. A buddy of mine, no its not my truck and I didn't do it, managed while installing new batteries to hook the right side battery up wrong. He hooked negative to positive and positive to negative . Fortunately he didn't have the other battery hooked up yet or he would have supplied 24 volts to a 12 volt system.
So he has it towed to my house for me to fix. Well it now has a fried alternator, he saw it smoking, two electrical draws, the instrument guages don't work and it cranks but will not start. Oh ya its a 2004 2500. The battery he hooked up wrong will not even take a charge now, can't get it over 11 volts.
One of the electrical draws is the circuit for the instrument cluster that doesn't work. I'm waiting for a dealer shop manual so I can check the electrical circuits.
Next to having to replace an almost new battery and the alternator anyone have any ideas on where to start looking for the no start condition while I wait for the manual to show up.
Thanks guys.
Wes.

 

Does that have a TCM in it? I forget.

Seems to me it has several computers similar to Can Buss, but operated independent of each other

You have a radio and heater. Make sure they are off. Can't think of anything else that could be doing that with a key on. One fuse at a time I guess

 

Polaraco
Not sure if it has a TCM in it or not, I haven't had time to dive into it yet. I have two fuses that have draws on them with the key off. With the key on I get nothing from the gauges, voltage gauge won't register anything. This will be an interesting repair and probably expensive. All because of a stupid mistake.
Thanks.
Wes.

 

One of those fuses may be keeping the ECM warm. Isn't the cover marked with a description inside? The other I dunno. Clock?

You can buy a wiring diagram on line in a PDF for 35 bucks. Google it.

 

One of the fuses is for a fan, can't think of what its called right now. The other fuse like I said is for the instrument cluster and some other stuff. I haven't had a chance to work on it yet. I'm waiting for the owner to get the alternator rebuilt and back to me and I am letting him buy the service manual. It was his dumb mistake in the first place. The computers shouldn't draw enough current to light a test light and these draws light it on nice and bright.
It will be fun figuring this one out. Best thing about this is that my truck runs just fine.

 

are you using the test light on the fuses?

Dash is all electronic. It may be driven by the ECM

 

truck has a pcm and a ecm. ecm is on the side of the block and runs the engine. pcm is on the firewall passenger side I think and it runs the transmission, and signals the dash through a bus, there is also a chip in the dash that reads the bus for the gauges. I should also mention that the ecm communicates the engine information with the pcm.

I would start with the pcm. there is a place online that rebuilds them and flashes you vin number and mileage back into them for a reasonable price.

ecm= engine control module
pcm = powertrain control module

You can get the wiring info on line for free if you search for awhile

hope this helps

 

Thanks guys for the help. I got the alternator back today and got it installed but didn't have time to do much of anything else. I did try to start it and it cranked over but didn't start. I have no fuel pressure to the fuel filter and have no response from any of the gauges. the instrument panel lights like the wait to start light, check engine light and other warning lights all work. I used the test light to check both sides of all the fuses and I install it between the negative battery cable and the negative battery post. If it lights then there is a current draw. The computers usually don't draw enough voltage to light a test light. If they did car batteries wouldn't last two days before they discharged. I will find out more next week when I dive into it. I will share what I find as I go. Thanks again guys for your ideas.
Wes.

 

An 04 would have been originally supplied with a manual lift pump so unless the lift pump has been replaced with an electric one you won't have fuel to the pressure pump unless the engine is turning over.

 

Ya this guy had the factory lift pump replaced a few years ago with a in the tank factory retro fit. I thought the factory pumps were all electric, I know the one on my 2000 dodge was electric. I replace it with a FASS before it went out.

 

Well after getting a factory manual and spending some time with it I have found that the one electrical draw was the vistronic fan but I think its due to the shorted out ECM. the other draw off the cluster fuse, #51, is normal and the factory manual recommends pulling the fuse if the vehicle sits for more that 30 days without running. I still have no gauges, no radio, and no door locks but everything else electric works. Everything electric goes through and is monitored or controlled by the instrument cluster so I believe the cluster is bad also but will wait until the new ecm is installed and see if the gauges will work since the ecm communicates with the cluster.

 

What fuse are you talking about pulling for a prolonged storage?

 

The one the manual mentions that should be pulled if the vehicle is to be parked for a prolong period of time is fuse number 51. Its the one for the instrument cluster. I have been checking these circuits for a draw with a test light, I have not used a voltage meter yet but will today. I still think the draw on this circuit is much more than it should be. A draw on the system that is this much will draw the batteries down in only a few days of non usage. I realize the computers do have a parasitic draw but most won't be enough to draw enough current to light a test light.

 

Well guys I finally received the new ECM and instrument cluster today. I got them installed and after a 20 mile road test everything worked. It did have the check engine light on and the ABS and Brake light on but the ABS and brake light went out after several times stopping the truck. The ECM must have stored codes for all the sensors because I had 14 fault codes set. I ended up hooking up my scan tool and canceling the codes and all is well. Took the truck out for a twenty mile road test and all is well. Runs really well and the customer is happy. The job didn't cost what the dealer wanted for just the ECM.
So don't hook up your batteries backwards!!!
Wes.

 

Wes, that's good to hear. It sounds like you did a stellar job diagnosing the problem!