I have a 1988 F250 5.8L. I have a new battery, new solenoid (tested it works), new ignition switch (located on drive shaft under dash). All my lights work, all my dash lights work, and so on. Yet I have no power to my ignition when I turn it. I have not changed the actuator because it was moving the little rod to the ignition switch. The key turns but gives me nothing. When I turn the key the lights in the truck and radio all dim down as if all the power is being sent to the starter. My question is why am I not getting any power to the ignition. Would the ignition coil have anything to do with that. Could the actuator not be pushing the metal rod far enough into the ignition switch. I’m baffled. I know the starter works because when I jumped the solenoid it was turning over. My next step is to follow the small wire on the solenoid back to the fire wall control module and see if its connected properly. Does anybody have any suggestions. I’ve been reading, you tubing and so on to find a direct answer but I have not come across anything yet. That I have not tired.

 

First question,,

Is it an automatic or manual?

Second question, you don't have 'any' power at the ignition switch at all , yellow wires..

Power ditribution for the solenoid is through the neutral safety switch from the switched/closed ignition, or manual, the clutch safety/interlock..

Reading your post it sounds like you have no power at the switch connector, but need that confirmed before moving on..

 

The truck is an automatic. I'm not 100% sure if I have power going to the switch from the solenoid or vs versa. ( meaning the little wire on the S position) Where do you suggest testing or how to test it?

 

Ok..

If you have 12v at the ignition switch, use a test meter or continuity light and probe the back of the ignition switch connector. If the switch is good, you should see current pass through on a crank attempt on the Red/Light Blue wire there. Yes/No?

If you have 12v there, you might do a quick check at the neutral safety switch.. You should have 12v there (on a crank/start attempt) on the red/light blue, and white/pink circuits.. Pretty sure on the wire color/tracers.. (?)

 

Ok I found that I have 12v at ignition switch. I had a hard time getting to the neutral safety switch wires to test them correctly. When I followed the wires up to the engine compartment I came to a wire harness that is square. This harness also has the wires that connect to the rear lights. Upon examination The wires all broke loose and are now unattached. So I'm guessing that I never had power to the neutral safety switch in the first place. I did prior to the wires breaking have rear lights that worked. So I tried looking for a replacement but now I don't know what part number or the proper name of the harness. Any thoughts? I did get a read at the neutral safety switch in the end and it did not produce any power. Does anybody know of a good diagram or book that explains or names out wire harnesses? My Chilton book just does not seem to do the job right. I don't mind going to the salvage yard to get this but would prefer to get a new one. I don't want to solder one of these in again.

 

I figured I would add the picture of the harness so everbody would know what I'm talking about.

 

Ok everyone, I got the truck running and I wanted to offer up the process on how I did it. I first fixed the wire harness that ran the rear lights, neutral safetyswitch and fuel pump and various other things. The truck was turning over but that was it. So I questioned if I was getting any fuel. This truck has been sitting for over a year according to the previous owner. Anyways I took off the pressure cap on the rail and put the ignition key in the run position . This is located on top of the engine, DS above the plug wires. I did not have any pressure. So I assumed my fuel pump was not working. I did not hear the pump working either. After I tested the volts I realized I was only getting 6.5 volts. (Fuel pump is located under the DS door on the frame) Thanks to this website I was able to determine that it was the EEC that was not working. (located under thehood DS right next to the air filter) So I replaced that and walla!!! The truckis running now. I now have to fix a seized up rear brake, give it a tune up and once the old fuel is out change out the fuel filter. Thanks to sites like this I was able to figure it out. Now my $500.00 buy is not looking so bad.

 

that brake drum is going to a real bear to take off being as how it stuck to the shoes. Good luck on it