I'm chasing a no start in P or N issue. I replaced the fender mounted relay and I can jump the terminals to start the truck, so the batteries, relay and starter appear good. I then installed a new DTR sensor (just unplugged electrical connection from tranny mounted DTR and plugged in a new DTR that I left dangling) and still no start in P or N. The dangling DTR was in N so it should have started if the DTR was the culprit (right?). So I assume the old DTR is still good. All that's left appears to be the Ignition Switch, but I replaced it about a year ago. Has anyone had an issue with one going bad so fast? It's an Autozone Duralast Ignition Switch and not OEM.

When I turn the key to Run all the dash lights come on like they usually do. When I turn the key to Start, all I can hear is the relay click. I think I've pretty much ruled everything out other than the Ignition Switch, or some random wire a mouse chewed through. Is there anything else I can look at? I've been using the Haynes manual electrical diagram and I don't see anything else in the circuit that could be the issue.

I hate just throwing parts at it but it's 110* outside so laying underneath (or being inside the truck for that matter) for more than 10 minutes is brutal. Hoping to target some things to look before I go outside. Thanks

 

Is this the truck in your signature?

Which relay is clicking? If the one on the firewall, there's nothing wrong with the ignition switch, the DTR switch, or anything in that circuit.

Which specific terminals are you jumping?

 

Yes, the one in my signature.
The relay I think I hear is the starter motor relay on the passenger fender (the one I replaced). It could also be no sound as I'm not sure how loud of a click it should be. If I hear anything it's faint. It's not a loud click. I'll try again when I get home, but if there's no loud clicking, what would that point to then, given I replaced the starter motor relay?

Thanks

 

Try jumping the small terminal to the HOT from the battery and see if the relay energizes and it cranks.

Your symptoms indicate that the starter relay isn't passing power. Either it's defective (the previous test will tell that) or it isn't getting the trigger signal (small terminal) from the rest of the starter circuit. You need to determine whether or not that trigger signal is present in START.

Note: That wire, if disconnected, will usually show 5-7 volts on it. Ignore that stray voltage. Look for full battery voltage there in START.

 

I was able to crank the engine over by jumping the small terminal to the HOT from the battery.

I paid closer attention when I turned the key and no click.

I connected an alligator clip to the Ignition Switch (connects to small terminal) and battery - and only get something like 60mV in Run and Start. Tells me the signal isn't getting to the starter relay, which comes from the Ignition Switch I believe.

Both the starter relay and Ignition Switch are fairly new. I'd hate to think it's a dead Ignition Switch after les than a year. But it is a Duralast....

 

Do not jump to any conclusions, there is still work to be done to get you into the right area of the circuit.

Check fuse F20 under the dash and 1) verify it is not blown, 2) is making proper connections in its socket, and 3) is HOT IN START.

ALWAYS HOT power is fed to the ignition switch. In START, power is sent from the switch to F20, then to the DTR switch, then to the starter relay. You have to pinpoint where the voltage is getting lost.

 

Ok, sorry for the delay. Finally got to 105* and I could get under the dash.
1) The fuse is not blown.
2) It is tight in the socket
3) no VDC when I turn the key. I do hear a relay click when I turn the key.

I looked briefly at the switch wires coming out but it's a nest of taps and stuff from the prior owner adding his own remote entry garbage to the truck, and rewiring the horn to a small button. The steering wheel buttons don't seem to work for anything (cruise, horn, etc) so that's another thing to look at later.

Based on your comment, I would take this to mean power is not coming from the Ignition Switch.

 

Correct, assuming you made that measurement at CJB F20 with the ignition switch in the START position.

Time to check ignition switch. Gain access to the switch's connectors, backprobe the pins and verify you have ALWAYS HOT power on terminals B4 & B5 from BJB F116 (LG/VT wire). Turn switch to START and verify power to terminal ST (RD/LG wire). You may need to clean out the PO's "work"....

Schematic:

 

Thanks again for being the calm voice in this.

I pulled the Ignition Switch connector to get a better look at the wires. Appears the prior owner spliced the RD/LB power wire to power the remote keyless entry. When the box was removed the male/female connectors were just pushed together to complete the circuit, and they just finally came apart causing the no start. When I pushed them back together it started right up. I pulled the whole wire mess and butt spliced the RD/LB wire back together and Bob's your uncle, it fires right up now.

Thanks again.