1990 e-150 5.0l

I'm driving the rig on the way back from filling up both gas tanks, and the engine cuts out like a light. No sputter or stall, just "lights out" (Not the actual lights, those work fine).

The first thing I notice is no dummy check engine light. The second thing I notice is no fuel pump prime when the ignition is in run. It cranks, but no start. No fuel at the rail. No spark.

I pull the pcm, still no spark. I open the case, no signs of damage, capacitors look good. I check the voltage at pins 1 and 37 (always hot and hot in run/start), and 0.01v. Pin 60 (ground) shows 13.8v. No power to the pcm explains the no fuel/no spark, but why no power to the pcm? I replace the EEC relay, and the fuel pump relay while I'm there. No change. The relays don't open when the key is turned to run.

Grounding the 6th pin in the DLC test plug while the key is in run does not give a response from the fuel relay or either fuel pump.

Horn stopped working, wiper blades work but the wiper fluid isn't pumping. Just a few things that might hopefully help someone pinpoint what and where the fault might be.

The kicker is that I can't find the power distribution box anywhere. That would be the first place to check I'd think, but I'm not seeing one. I'm suspecting there isn't one.

Any ideas?

 

Suggest you check for power from the starter relay through the fusible links to the fuse panel. I believe power comes from the battery positive post to the post on the relay and from there through a few fusible links on to the fuse panel, ign etc.

 

Thanks for the reply, hanky


I swapped the three fusible links coming off of the starter relay, and there is no change. I found another link that seemed like it may be bad, a yellow wire I assume is the ignition wire, and I thought for sure that would do it, but still nothing.

 

Some questions,
Do you have any power at all to the ign switch ? I suspect there is a problem either with power coming to the ign switch (in which case the wipers shouldn't work) , but they do! There must be a problem at the fuse panel itself and you may need to remove the screws and look at the back of the fuse panel. As you know power comes from the ign switch to the EEC relay and if there is no power coming there it has to be between the fuse panel and the other circuits those fuses supply. Look for rusted or corroded connections at the fuses themselves.

 

It's unholy how cold it is outside. As soon as my bones warm up, I'll head out and check. It would make sense that the fuse box might have bad/corroded/rusted connections. It sure has been raining a bunch, and I just discovered a leak down the drivers side of the windshield...

 

You don't have to tell me what it's like trying to electrical work outside when it is just plain cold!! Do you get any action when you turn the key to the start position? If so, you might run a jumper from the battery positive post to the terminal of the ign coil that comes from the ign switch. That would backfeed everything the ign sw supplies and at least be able to get the vehicle started and warmed up some.

That yellow wire/fusible link may be the one you are after.

 

I get crank. I'm a super noob on a crash course. I hate asking, but would you mind explaining this ign jumping thing like I'm 5 years old?

 

At this point, just hearing her run will make my day.

 

I figured it out, and you were right, hanky. Jumpering the ignition coil + to the battery let me start and run it.

If you're as noobish as I am, here's how to do it: There are three wires coming from the ignition coil- a pair of green and a red. The red one was isolated from the green and closest to the driver's side (in case yours aren't red and green). The other end of wire you've rigged up touches the battery + post.

Everything clicked on right away - fuel pump, relays, check engine light, horn lol. That yellow fusible link I mentioned earlier is getting 12v, and I have confirmed in my repair manual that it's the + to my ignition. I have no power to the coil, though. The red wire on the ign coil shows 0 while cranking.

I'll update once I pinpoint the problem or if I get lost.

 

First , I can only hope that the fusible link that opened , opened due to age.
Now,
the ign coil should have to wires coming to it . These are for the primary winding.
One of the wires comes from the ign switch, and the other comes from the ign module that gets the signal from the pick up coil in the dist that tells the coil to fire when that second wire gets grounded. What we are attempting to do is provide power to the coil terminal that would normally get power from the ign switch when the key is turned on. When the key is turned on it provides power(voltage) to various circuits one of which is the ign coil. That connection we make by providing power to the one coil terminal will also back feed power to all the other circuits the switch feeds. By connecting a wire from the battery positive terminal directly to that terminal on the coil by passes the normal ign feed and as long as the starter will crank the engine over the engine should start. You will need to disconnect the wire to shut the engine off because we by passed the ign switch.
If you choose not to do this you can always confirm that the yellow wire with the fusible link is open and jump it there. You should read battery voltage on both sides of the fusible link which we check by pulling on that wire and if it is open it will stretch easily because there is no wire connection internally.