I've got a 1996 Ram Van 3500 with a 5.9. It'll crank but won't start. I pulled one of the plugs and no spark. A also checked for spark coming directly off the coil and nothing. I've also checked for power to the coil by checking for voltage across the plug that feeds into the bottom of the coil with the ignition in the on position and while cranking and the multimeter doesn't budge. Also, the CEL has not come on.

I assume this means that the crankshaft postion sensor may be OK (if there was voltage to the ignition coil then most likely the crank position sensor would be bad)? So that would leave the ASD relay or the PCM? Is that a correct assumption. It also looks like I may not be getting fuel pressure. I placed a rag over the schrader valve on the fuel rail and pressed the valve. Fuel just sort of trickled out- I assume that if there was fuel pressure, there would be a significant spray when the valve is depressed.

Thanks for any help.


Steve

 

Both the fuel pump and ASD relays share a common power source. You didn't mention if you checked any blown fuses. The fuse you'd be looking for is usually #1 in the box under the hood.

 

OK, thanks for the feedback. I gave a quick look at the fuses a while ago, but didn't really know what ones to look at. I'll double check the #1 fuse next (won't be able to look at the van again until a day or two). Also, for reference, I tried swapping the ASD relay with the A/C relay and still nothing.

Steve

 

I checked all the fuses under the hood and all of them under the dash with a multimeter and they all have continuity, so the fuses are OK. I also checked for fuel pressure again (by pressing the schrader valve on the fuel rail) and nothing.

Are there any other fuses or circuit breakers I should be checking? Last couple times I tried to start it, the battery was dead and I was trying to jump it, so I'm wondering if that blew something. I've since gotten a new battery.

The check engine light is off, but I'm wondering if there would be any value in checking it with a code scanner (which I don't have and would have to buy).

Any recommendations on where to go from here?

Steve

 

I still say you're not getting power through the fuel pump and ABS relays. You need to troubleshoot those circuits to see where the power is stopping.

 

Checked for voltage across the ASD relay terminals and there is 12 volts there. Not sure where to check next.

 

By across do you mean one lead on each contact at the same time, or one lead to ground then 12v on each contact, one at a time?

 

I checked for voltage across the two terminals that I believe would be the ones that provide power to the coil. Each relay has five terminals, three aligned in parallel to each other and then two perpendicular to the other three. I think the three in parallel are the ones used to activate the relay and switch power on/off between the other two. I checked voltage by probing across the two terminals perpendicular to the three.

Sorry if my terminology isn't too clear, I'm not much of an electrician. If I should be checking some other way, I'll gladly do it. Thanks for the help.

 

Those are the normally open and normally closed contacts. Here, read this page and it should help to explain the relay pinout.
http://www.mmxpress.com/technical/relay_basics.htm

You should have 12v on 30 and 87a when the ignition is off. Then with the ignition on you should have 12v on 30 and 87. In both cases, one meter lead should be connected to negative while you use the other meter lead to check the relay terminals.

 

OK, thanks, I was definitely checking across the wrong terminals. I'll go back and re-check. For clarification, when you say the meter lead should be connected to "negative" do you mean connected to 30? to the negative battery lead? to the engine block (ground)? Or does it matter (I would assume all of these would be ground). Unfortunately my electric circuits skills are basically limited to one college course.

Thanks again for the help.