I have been working on a 90 W150 with a 318 and auto trans. The battery has been tested and is still good. The starter has also been tested and is good. It has a new ground cable. But when you try to start it doesnt try to turn over. There is some type of relay on the inner fender with 4 wires going in and when you try to start it it makes a clicking sound it has been swapped and they both did the same thing. my next thought was the ignition because when you turn to start the left turn signal light comes on in the dash. running out ideas thanks for the help.

 

Have you replaced the battery terminals. I had a new battery in my truck and was fine and a month later would not start. Tried jumping it and nothing. I replaced the terminals and fired right up

 

no i havent i might try that next.

 

Quick check, take a 12 volt test light and touch the smaller terminal of the starter while somebody from the cab turns the key to the crank position. This will tell you if you atleast have voltage to the crank side of the starter. Its pretty haard to test a starter out of the truck as you have no load to put on it.

Buster

 

It is not likely the switch if the start relay is working. Do you have 12 volts at the large terminal on the starter? If so jumper from there to the small terminal and see if the starter engages. Use something heavy for jumper like an old screw driver or pliers. If it does not engage the starter is suspect and should be pulled and taken to Advance Auto or the like for testing. If it engages but doesn't turn over I would make sure the engine is not frozen by turning it over by hand.

 

While the starter is installed, test the resistance from the case of that starter to the neg terminal on the battery. You should have very good continuity. If you do, then test for 12 volt at between starter solenoid terminal and the body of the starter, while someone is trying to crank the engine. Be careful.
If you have power and ground then the starter is bad. If not, trace back from the solenoid. This assumes you have 12v on the fat wire on the starter.

Good Luck

 

i took the starter off and took it to autozone and had it tested and it tested good. but i havent had time to put it back on yet. thanks for the tips.

 

ok i had some time to put the starter back on. on the main power wire i get 12.5 volts from the terminal to the case of the starter. on the little wire i get 12.5 volts when the key is turned. it still does nothing. i tried to jump the terminals with a screw driver and it does nothing. the motor is not locked up and i just had the starter tested and saw and heard it spinning. any ideas? thanks.

 

It must be in park or neutral. Don't be insulted I'm scratching for anything here. There is a problem with the starter solenoid, the battery, or the main battery cable. You are either not getting enough amps to the starter or the solenoid/contacts are bad. Have someone turn the key to the start position while you tap the starter/solenoid with a small hammer or screwdriver handle.

 

does your battery have a full charge? Might try another one, then make sure the alternator is working properly.