Hello all, been trolling the 70s forum for a while but just scored a $200 F150 off of Craigslist and need some advice! She's a 1984, has a 300 inline 6 with 127,000 miles, a Tremec 170, and I think an 8.8 out back. After replacing rotted battery cables and checking fluid levels I made the remark that "**** even after sitting for a decade with fresh gas she will probably start right up" and a bet was made. After confirming that the engine would turn by turning the crank bolt, we primed the carb, pulled the fuel line off of the fuel pump, stuck it in a gas can with fresh gas, jumpered the solenoid, and boom she came to life. Ran it for a few minutes to win my beer and check to see if the gauges work and I noticed that none of them do, hence my dilemma. The starter solenoid is shot, will that affect power to the gauges? I am a junkyard mechanic at best, and I'm trying to fix up this truck to sell cheap to an army buddy who had his life go south in a bad way. The budget is basically the only parts bought new are the ones that can't be found at a pick and pull yard so any and all advice will be appreciated!

 

I would check the fuses inside first since all the gauges do not work. I always start with the simple stuff and work my way through to the more complicated problems as it can save a lot of money !

 

Don't be so quick to condemn the solenoid.
If you don't have power in the cab, you won't have any power to trigger it.

Make sure the solenoid is grounded where it attaches to the fender.
Check for power at the little red/blue wire on the 'S' terminal when you turn the key all the way to Start.
Instead of jumping the two big lugs, try jumping from the battery+ lug to the 'S' terminal.

 

Jim/ArdWrknTrk is right - as always. The solenoid can't be pulled in if there's no power to the ignition switch in the cab. Wiring diagrams are on my web site, but you can start with this one: Charge & Power Distribution - Gasoline Engines - ???Gary's Garagemahal. It shows the feed to the cab on Page 15 in the upper right corner - Fuse Link M and then circuit 37, which is a yellow wire.

 

Wow, that was fast, thank you all for the quick replies! I do have power in the cab and to the dash, and the only fuse that was blown was the 30amp heater/blower motor. It wasn't just blown it was melted in place so bad that it burned out its housing, so i disconnected those two wires and capped them until I can get an inline fuse holder to rewire them. When I bypassed the solenoid to engage the starter I went from S to positive on the relay. After I posted this I read on one of these forums that I might have a bad NSS(or the manual trans equivalent) so I will be retesting everything today with the multi-meter. Gary that one link has already been more useful that my Haynes and Chilton manuals combined! Thanks again!

 

Oops! I forgot - WELCOME TO FTE!

Glad it helped.

 

So it's not a bad relay?

Clutch safety Interlock or NSS.
Look up under the dash and see if the switch closes with the pedal depressed.

 

So somehow I got sidetracked and didn't finish my sentence about the jumping the relay. I started by trying s to positive, just sparks and nothing else. Jumping the large posts actually engages the starter. Voltage to the s terminal is 11.2V. However I found this mess tucked behind the carb. Now I'm trying to trace where they are supposed to go. The red in the plastic harness triggers a continuity light when the key is turned to on, the others seem to do nothing.

 

Okay, so the solenoid is bad and you do have voltage to the S terminal when you turn the key to start.

Key on red power could be coil or other things.
It's hard for me to see on my phone, out in the sun.

 

Chopper, could you get a picture of the carb?
I am thinking it is not the carb for that year truck and the wires went to the carb.


As for gauges you said you looked over the fuses, I would pull them all clean the fuse ends or just replace them and clean all the holders and see what happens. I have had a few cars & trucks that sat for years and things did not work. Cleaned the fuses and holders and everything worked again.
Dave ----

 

Fuzzface, that is very possible as the two wires that were in the melted harness looked like they possibly were wired to this harness on the carb or smog equipment. According to my haynes the other two were for the blower motor. Also the red harness in the other pic looks like it should be hooked up to something, but there is nothing in the engine bay to plug it into.

 

That red connector was where you'd hook up a code reader to see what the computer had to say about things; there should be a single wire in a gray plastic housing with a spade connector in it someplace very nearby, it's also part of the code-reading system.

 

Thanks ctubutis, that single grey housing is indeed right next to it. Through testing as many components as I could today I have found the following:
Headlight, parking light(only one of each because of an accident that caused it to be parked for so long), and both taillights work. Hazards work, blinkers do not. Horn doesn't work, but the cigarette lighter does even though they are both on the same fuse. Instrument cluster back light works on the aftermarket tach, gauges do not. No buzzer when turning key to on. Interior dome light and radio work. I don't know how many of these are directly related other than the horn/lighter combo. Thanks again for all of the advice!

 

Wow.... I the EVTM on Gary's site will be a GREAT help to you with all that stuff....

 

Holy @#$%! Thank you for that link! If I would have found that earlier today I could have saved myself one hell of a headache! Looks like tomorrow after the seized up smog pump comes of it's round two with that mangled wiring harness! I don't know if I've said this yet but this forum rocks.