Sorry for jumping in here as a new member and getting straight to the point before an intro but I'm getting pretty frustarted.

I have an 89 W150 5.2L that will not start. No power to the + side of the coil which also powers up the fuel pump relay and injectors. I replaced the distributor a few months ago becuase it broke the pick up coil. A few months after that it wouldn't start and that's when I found that I wasn't getting any power at the coil. I checked all the power inputs and ground inputs at the SMEC and had them all so I replaced the SMEC....that didn't help. I'm looking for something that would not tell the SMEC to send power to the coil. I know it doesn't have a crank position sensor, what am I missing? Old Chevy's used to have the oil pressure switch that wouldn't allow power until it saw oil pressure but that didn't include Dodge's did it?

Any help will be greatly appreciated before this truck takes the long slow trip to the metal yard, lol. Thanks.

 

did you check the fuses? make sure to check for power at the fuses.

 

Have you checked the ASD relay and wiring circuit? The ASD controls power to the fuel pump and coil. Does the fuel pump run when you first turn on the key?

 

Fuses were the first thing I checked. Even replaced the ignition switch thinking no power to that side during cranking. Ok, so the ASD relay or fuel pump relay on an 89, I have power except on the green wire that energizes the fuel pump and am thinking thats powered thru the SMEC. I get occasional initial power on that side of the ASD/fuel pump relay when I turn the key to the power side, nothing on the crank side and only occasional. So, if this truck doesn't have a crank sensor, what closes the circut on the ASD relay? I'm missing something here and its been so long since I've done any extensive work on this year trucks that I've forgotten what initializes the ignition circut.

 

Does anybody also have the specific diagnostic procedures for checking the distributor pick up? My guess is even though I replaced the distributor a few months back with a reman, that in the order of things, if the SMEC doesn't see some kind of initial signal from the pick up, it will not energize power to the coil/ASD/fuel pump relay. Am I correct assuming this?

 

The ASD relay gets power to the contacts thru a fusible link straight from the battery (14 gauge red wire). The relay is energized by the SMEC (14 gauge dark blue wire) when the key is turned on. If you have power to these two wires with the key on and no power to the 14 gauge dark blue/black or the 16 gauge green to the pump the relay is not working.

In the distributor, pick-up coils were used from 1974-1987. 1988-1991 used a Hall Effect switch. If you PM me your e-mail address I will send you the trouble shooting procedure.

 

Seal, pm is on its way, thank you.

 

As an update, the truck is running with the replacement of the Hall Switch. Originally I wasn't looking at the distributor because I had replaced the unit not long ago because it had broken apart. My first clue that it was the Hall switch was when I was testing the terminals for power and touched one of the other terminals and heard the injector fire off. The injector power is on the same circut as the distributor and several other components. What the SMEC wasn't seeing is the distributor signal so it wasn't sending any power to that circut.

 

hhheeeeeellllpppp!!!!!
i have tried everything!!! I have a 1989 W150 with 5.9L it has been morphodited in the past, i am trying to unmorph it, it had a intake and carb on it and it ran, not well. i ordered a correct intake and t- body from a junk yard, and put them on and now there is no spark. i had also replaced the fuel pump. the fuel pump is not coming on, until i run a hot wire to the coil. i tried replacing the relays on the drivers inner fender with no change. i checked and replaced coil, no change. i checked and replaced pick up coil in distributor, no change. the coil is getting +/- 7 volts to positive side. the neg side of coil is getting and intermittent fluctuation of up to 1.5 volts. which from what i have read in the manual, this is about correct.

this truck does not come with the resistor on the firewall, ther is not even a place for one, it also does not have the seperate ignition box on fender well, nor does it have a place for it.

i am at my wits end, and i need help. this truck will never go to the scrap yard because it is all i have left from my dad!