Problems with my 1980 f-250. Please, help.
I had to boost my truck the other day and the friend I called, God love him, hooked his duramax diesel up but crossed his end of the cables . After the ensuing spark show I couldn't start my truck. Changed the solenoid on the fender for a jobber picked up at Lordco. Now, it don't get even a click, let alone a crank when I turn the key. I have changed the fusible links, battery cables and cable heads. Still nothing to the ignition. Battery has a full charge and all other systems have power. What should I try next?
And does anyone know where to find a free set of wiring schematics for the engine bay?

 

Gary’s Garagemahal has some good wiring information.

Are you saying that none of the ignition switch fed systems are getting power (radio, starter circuit, etc.) but things like headlight are?

If you can narrow down what you have and don’t have, I have a 1980 EVTM and may can lend some help.

 

the radio heater fan – lights interior light horn all seemed to work fine but when I turn the key to start it absolutely nothing happens

 

Time for some basic troubleshooting. No more throwing parts at the problem in hopes of a fix.

Amongst other parts lobbed at your poor truck, you mentioned replacing the "cable heads". Are you talking about those bolt-on emergency battery cable terminals, sold next to the pine tree air fresheners at the parts store counter?


If so, please slap yourself and save me the hassle. Those things are nothing but trouble. They'd work well as weights for deep sea fishing. Good paperweight, too, though a bit unwieldy. That's the end of my list of good uses for those things. Note "battery terminals" is not on the list. The problem is they often only allow small amounts of current to flow. Might be enough to power most systems, but not the starter. You're left standing there, scratching your head. Glad we caught you before you changed the starter.

At your starter relay (on the fender), disconnect the small S terminal. Connect your voltmeter to this wire. Have a helper momentarily turn the key to start. Do you see battery voltage here? Please try that and report back.

 

I am inexperienced with the truck, not wrenching in general.

And secondly, I don't own a meter of any sort, as some kind soul took all 3 of mine shortly before Christmas, with about $1300 in 1/2" and 3/4" drive sockets from my home.

 

Some more thoughts, in no particular order.

You mentioned a shower of sparks when the jumper cables were connected backwards. Where was the sparking? If not right at the jumper connection, this would indicate a weak spot that let go.

Your alternator may be toast. Specifically, the big internal diodes may have failed. Depending exactly how they failed, they may now be causing a short to ground that is depleting your battery. If not doing that, it may still prevent the alternator from charging properly. For now, concentrate on the present no-crank condition, and come back to this later. I'd suggest disconnecting the alternator in the meantime. This big wire will be hot with battery power, so disconnect the battery ground cable first for safety. Then you can safely disconnect the big cable from the alternator. Wrap it with several layers of electrical tape and secure it out of the way. Unplug any other connectors, too.

Get a charger on that poor battery. Remember, it was already run down enough that you needed a jump. Don't count on an unloaded voltage reading to determine the state of charge. It's very easy to get a misleading indication that the charge is good. Don't use a trickle charger. You need a charger with at least a ten amp output.

 

You're going to need one. You're working blind without a meter.

 

In the picture below, that little terminal stud on the solenoid has nothing on it. I am going by memory here, but I think that is the one the red/blue wire should be on to start. The other one with some sort of red tape wad will not have anything on it. I think I am right, the "s" terminal should be hooked up, the "i" terminal will be bare.

 

I thought I did a post saying you can use a test light you can get at the auto parts store for most testing.

I also asked for a better picture of the starter relay (solenoid) but DaveF pointed out what I was trying to see.
A wire that is hot when the key is turned to start needs to go on the stud "S".
And to prove this take a screw driver and go from the battery stud and that "S" stud just make sure the truck is out of gear if a stick or park if auto and the motor should crank over and if the key is on may start & run.
Dave ----

 

I have been wrenching for a living for nearly twenty years. I am, however, not used to vehicles my OBD2 can't scan. The parts I've "thrown at" this truck were Soares that came with it and figured it couldn't hurt to try.
it makes zero difference which terminal the trigger wire is on. I still have no crank, click or anything else when I turn the key. The battery is at 100% and has stayed there. (Just used it to fire up my generator) since I charged it two days ago.
So if we are quite done being condescending, I need to know the following:
1, what components are supposed to be grounded on this circuit? There are a few little boxes

These supposed to be grounded? And are they possibly the weak link that blew out when the cables went on wrong? I have spares for my '85 p30 chassis( unfortunately my RV was made by GM). Are they interchangable?

That go to the hot side of the solenoid. If those could cause my issue I have spares. But I know nothing about what they are called or their purpose. Thank you guys for your time and consideration. Talk to y'all tomorrow

 

Forgive these guys, they don't get out much. No telling what damage was caused during the fireworks display. I'd just start at one end at head towards the other. I'd check for power on the ignition wire to the starter relay first. I know you said you've been relieved of your meters, test light will work if you have one, if not try and jump the I terminal on the relay from the hot side. Screwdrivers work for that, but I like to use jumper cables or a remote start switch now that I have one. Try that, give it just a quick kiss and see if it offers to fire. If it does, work back towards the ignition and any safety switches you may have. If it doesn't, check your cables, hot and ground going to the starter. One may have burned up when your friend loaded the system for you.

 

The solenoid/relay is wired all wrong. Give us a closer pic of the starter relay so we can see all the wires on it and can sort it out for ya.

 

And that is precisely where I've put them. Now, can someone PLEASE tell me what these are......

The one I'm holding, as well as the one near the inner fender
AND IF: A ,they could cause my problems,
B, if they should be grounded/mounted and
C, if the exact same units from a GM chassis will work as replacements. Thanks guys.

 

The thing in your hand looks to be a relay to what who knows, maybe extra lights?, as it is not factory from what I see.
That 2 post thing bolt to the inner fender is a circuit breaker (fuse that reset its self) that could have been used for trailer brakes power in, also not factory from what I see.
If you trace them out to see where they go would help you later if something else is not working or the other end is not going to anything remove them.

Now lets see a picture of the relay / solenoid all the wires are hooked to so we can see if the wires are hook up right.
It would not be the first time someone replace it and hooked the wires up wrong.
Also what is up with that red (tape?) stuff on the wires to the relay?

BTW this truck works the same way as a OBDI or OBDII system just does not have a computer to control everything so it is easy to fix.
If a OBDI or OBDII system had no power going to it so the computer cant tell you what is wrong how would you fix it?
I have told a few "kids" what was wrong with my 02 Dodge way before they hooked a computer to it to tell them.
Good luck
Dave ----