Short somewhere?
Postmaster
Joined: Nov 2011
Posts: 3,533
Likes: 17
From: SW Florida
So if ALL you get is the odometer backlight and nothing else (no fuel pump, no idiot lights, no voltmeter reading) when you turn the key, I'd say you have a blown fuse or bad switch somewhere.
Now to answer the question in your first post about a short, you have an open circuit(s) somewhere. This can be CAUSED by a short which in turn blows a fuse, so the reason I'm telling you this is when you go to check your fuses DON'T just chuck a blown fuse in the trash if you find one. Look at it first. If there is a dead short somewhere, even if it's only intermittent, then the fusible link (the little metal wire) inside the fuse cartridge will be instantly vaporized and you'll see the black scorch marks inside the fuse. If you don't see the scorch marks but rather just see the link has melted, that's a sign that there was either a partial short or overload downstream in that circuit.
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New User
Joined: Jun 2006
Posts: 11
Likes: 0
Unless there is a single fuse hanging somewhere, I have checked and changed all the fuses in both power distribution boxes. Where is the neutral switch that I have heard several of you gentlemen mention. About the ignition switch wiring, I understand that there are certain contacts that would be open and closed at particular times... but I was thinking beyond switch at the coupling, if any of the pins grounded to chassis, this could possibly narrow down a wiring short? Any input?
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New User
Joined: Jun 2006
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Alright, starting over. When I turn ignition key, I do not hear a click by the solenoid, there is no voltage running to the small post to activate the solenoid. When I jump the large posts on solenoid, the truck turns over. On the dash, when I turn key, the speedometer needle drops below the 0 mph line. No clicks, no lights. I have tried to start in neutral to no avail. It sounds like the odometer going off is correct from what you are saying. Turn signals are functional as well as headlights, flashers, and tail lights. There are no dome or dash lights except when blinkers or flashers are activated.
Lead Driver
Joined: Oct 2003
Posts: 8,476
Likes: 37
From: Madison, WI
The NSS is on the transmission. IIRC, the wires for the start circuit are blue/red. Your tests indicate a problem in the wiring upstream of the starter relay, so the NSS is a prime suspect. One other test to confirm - instead of jumping the large terminals on the starter relay, jump a wire from the battery + to the small terminal on the relay. If the engine cranks, then that confirms the relay is good and the problem is indeed upstream.
Have you tried leaving the key in the RUN position, then jumping the starter relay?
Have you tried leaving the key in the RUN position, then jumping the starter relay?
Fleet Mechanic
Joined: Mar 2014
Posts: 1,926
Likes: 116
From: Saskatchewan Canada
The engine should fire up. This is important to know because it would mean the difference between troubleshooting a simple no crank scenario or a more complex problem affecting other electrical circuits as well.
It is good to know your lighting circuits are working. This eliminates a general power distribution problem in the truck. At least we now know there is power in the cab.
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New User
Joined: Jun 2006
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starter relay works fine by jumping it from the small post. I have tried leaving key in run position and jumping it. It turns over fine. but nothing in the fuel intake. the wire that hooks up to the small post typically for the starter relay has zero voltage when key in start position. as soon as it stops raining I will check switch on transmission. thanks
Lead Driver
Joined: Jul 2007
Posts: 7,868
Likes: 9
From: Rhode Island
starter relay works fine by jumping it from the small post. I have tried leaving key in run position and jumping it. It turns over fine. but nothing in the fuel intake. the wire that hooks up to the small post typically for the starter relay has zero voltage when key in start position. as soon as it stops raining I will check switch on transmission. thanks
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Lead Driver
Joined: Oct 2003
Posts: 8,476
Likes: 37
From: Madison, WI
Oh, to the OP's question about a diagram - there isn't "a" diagram. Wiring for a vehicle like this requires an entire book. Good one to have on hand, BTW; it's called the EVTM - Electrical and Vacuum Troubleshooting Manual. There are PDF and other online versions, but they're not much help when you're slithering under the truck poking a tranny switch with a meter, or jumping between pages. Good for sitting-at-a-desk reference, however.
Fleet Mechanic
Joined: Mar 2014
Posts: 1,926
Likes: 116
From: Saskatchewan Canada
starter relay works fine by jumping it from the small post. I have tried leaving key in run position and jumping it. It turns over fine. but nothing in the fuel intake. the wire that hooks up to the small post typically for the starter relay has zero voltage when key in start position. as soon as it stops raining I will check switch on transmission. thanks
Good luck and let us know how this turns out.
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