Do you have access to a digital voltmeter and a testlight?
What is the battery voltage key on engine off? Turn the key to the start position and tell me what the voltage is now...
Voltage is 13 volts both ways. I didn't see any change but did hear a sound like the release of air? up near the brake master cylinder area
Not sure you got my answer?
Which engine is in your truck? I'll assume it's equipped with an automatic transmission.
Ok, there have been problems with starter relays. Do you need a relay box diagram?
The starter relay in the underhood fuse block connects the purple wire on the starter to the feed available at FUSE IGN A (FUSE 49) 40A in the underhood fuse box.
It does this when feed from the ignition switch (which passes through the ENG 1 fuse (fuse 23) is available to the starter relay and ground is provided through the starter enable relay control circuit in the PCM .
The pcm provides ground on this circuit when it sees the start signal from the ignition switch. This start signal can be checked at the CRANK fuse (fuse 27).
Check these points while cranking and get back to me.
I have 12 volt to the relay on the coil side and the power side on the pins to ground and when key is turned to start I get the gound and 12 volts accross the 2 pins to the relay
did you get this reply?
Can you test for voltage at the purple wire on the starter motor ?