7.3 Dead with no electrical power!

[oregon101]

Well my 89 7.3 is dead in the water!! I started it at work to warm up before I left and went back inside for a couple of minutes. When I came back out it had died. I went to restart it and had no electrical power. The under hood light will come on and I have power at the position #1 on the fuse panel (it's the hazard lights). All other electrical items are dead with no power. I'm guessing a fuse link went? Any suggestions on were to start?

 

[fastass350]

Maybe start with the hot lead that comes off the passenger positive battery terminal and goes to the solinoid (should be that way on an 89) Most all the key on functions run off of that. Sometimes it breaks or gets loose. Also try wiggling your key as it can sometime be in the switch down on the column itself.

Let us know...

Chris

 

[oregon101]

I did wiggle the key and cycled it several times. The relay by the battery on the passenger side has power on both sides.

 

[punkmechanic]

just a thought, but have you done a voltage drop on your ground cable? if your ground cable was going and now broke you can have power everywhere but no path back to the battery.

punk

 

[fastass350]

Goodness, have me baffled...but that is a few years newer than mine so that wiring I'm not too famliar with. But, I am headed to Eugene tomorrow morning, leaving the Porland area around 0730 (that'd be Wednesday) so if you still need some help with it PM me with your number (before 0730) and I'd be glad to stop in and help you with it if I can. I'll still search around for a wiring diagram online tonight, since I don't have my book with me at this time.

Chris

 

[oregon101]

I'm going to look into it tomorrow in the daylight. Thanks for all the fast replies! I will keep everyone posted on what happens.

 

[BigRigTech]

Start with the basics, check your cables and clean your battery posts. Voltage drop your cables/connections and see where the power stops...My bet is a fusible link between the fender relay and the cab, I had the same thing happen on my old 88 F150 gasser - corrosion on the heavy yellow wire to the cab took the power away....Too bad I wasn't closer - I'd have it cased in a jiff.

 

[oregon101]

It's Alive!! I finally got a chance to look at it yesterday and found the problem. Someone in the past did a terrible repair job on the wiring by the main relay and it shorted out. I repaired it and now it runs great again. Thanks for all the fast replies!