94 Dakota 3.9 Fuel problem

[ksmaxey]

My 94 dakota wouldn't start - (168000 miles) I hooked up a gauge and had no fuel pressure - presumed the pump went bad - replaced it - nothing.

In tracing the wiring I am not getting the proper voltage to the pump (appears to be .5 volt. - even the initial second after the ignition is turned on)

I replaced the relay - there is clearly 12 volts coming into the relay. I can see the relay connectors energize when the ignition is on - but I only get .5 volt on the line to the pump. (I tapped it in the engine compartment thinking there might be a short on the wire run.)

Any suggestions about what to try next?

Thank you in advance.

[ksmaxey]

I tried to read the engine code via the check engine light. I can't get it to flash (worked several years ago in diagnosing a bad O2 sensor.

It makes me wonder if the computer is fried. Any thoughts? I don't own a code reader - hate to spend 300 to learn that the computer is fried.

Kevin

[BleedDodge]

You're probably right about the computer being fried.

[ksmaxey]

I talked to a guy who teaches mechanics. He had me test the map & TPS sensors to see if I was getting 5 volts. I am not. I also am not getting any voltage going into the ignition coil. (well when I crank it shows .06 volts.

His take was that the computer wasn't getting all the ground it needed or one of the power inputs from the system was bad. I haven't been able to trace that yet.

[ksmaxey]

ok - ruled out fuel problem. Clearly now electrical. I don't think I am getting enough power to the ecm/computer.

I found two fusible links. Both passed a simple connectivity test.

The two I found were on the drivers side fender under the washer reservoir.

Does anyone know of any others?

[techaddict5610]

Could be your Ignition Switch. I'd start at the battery, and trace/check all feeds that go to the Computer. Also remove the connector plug at the computer, and make sure there isn't any corrosion on the contacts in there. I still think it is most likely in your Ignition switch, or the main supply lead into it because that could be why you're not getting any appreciable current at the fuel pump...or the coil.

[jkdon]

Its that wire harness under the fuse box in the engine compartment. Search some of the old threads. Mine would die sometimes not start. pull relay box unwrap wireharness about a foot back and check the 3-wire splice for a bad factory solder.

Jkdon

[techaddict5610]

jkdon, I sure am glad I read your reply to this topic!

I just finished repairing the splice on my truck that you pointed out.

It was a pitiful job of soldering.

I can only figure that some boss at the plant in those days of production must have raised hell about the amount of solder being used to put those harnesses together.

There was barely enough on my wires to stick it together!

I thank you for taking the time to post that, and want you to know that you may have saved me a towing bill, lot of headache, and inconvienience by pointing that out. Not just me, but probably a few other folks as well. Best of everything to you. - Jay

[89ltd]

I take it the truck runs now? That was the problem?