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Electrical Headaches...

76k5blazerr

76k5blazerr

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Alright guys I've got a few electrical problems with my truck I'm hoping to get some help with. I was actually thinking about breaking the rules and taking it to a shop and having them go through the wiring but I might take a swing at it first. So the first problem is sometimes when the truck has been running for a while and you cut it off, it won't crank back up till it cools off. Like the starter doesn't even engage, just nothing. Then when it sits for a little bit it will work again. Next, the fuse for my gauge panel, taillights and interior lights (one fuse) keeps blowing on me. Like once a week. Weird right. And then another thing it does it sometimes when you turn the headlights on the left turn signal will come on and not blink, just stay on. And it makes the left headlight go dim. And the last thing I think is sometimes I'll be driving and the radio faceplate will just go dark and stop working but the radio keeps playing. Like the buttons and knobs on it stop working so you can't adjust the volume or nothin but the music is still playing. I swear this truck has a ghost in it. Any help will be appreciated guys and if any of yall have any idea what it would cost me at an independent shop to have the electrical system gone through I would like to hear what you think. Cheap or expensive? And the last thing, are the back lights in the gauge panel easy to find to replace because after the last fuse blowing I think they have burnt out because they don't come on anymore. Sorry for the long post, thanks in advance for the help.
 
You should inspect the wiring around the starter motor. The wiring in this area has a tendency to get hot and melt when not properly shielded and routed correctly. Also, the fusible link wires can go bad as well when they get old, yet still look OK.
 
I doubt anyone will tell you to go to a shop or they wouldn't be on here. The shops around here will charge $75/hour so you could be looking at $500 or more. These trucks are dead simple to work on and we can walk you through any problem you have and how to diagnose it. The only thing I'd say to take to a shop is a tranny rebuild, but even that some members can guide you through it.
The starter problem could be a heat soak issue, especially if you have headers that run close to the starter. The fix for that is to remotely mount the starter solenoid, usually with a Ford solenoid. I had that problem a couple times with the stock exhaust but it was 110 outside.
The fuse blowing intermittently is obviously a short (drawing too much current) or someone could have added some other device to that circuit causing it to overload. You'll need to investigate that further. Do you have a multimeter? If not then it's a tool you need in order to do any electrical work. They're easy to use, learn how to use one.
The blinker - you may just need to replace the flasher for the turn signal ... or your blinker fluid may need to be recharged :D - someone else will know better.
The radio - is it aftermarket or the stock? More than likely it's a faulty radio.
The dash lights are found at any auto parts store and easy to replace, just unscrew the dash and it should be self explanatory, but I'd find that possible short you have or you may be replacing them again.
 
Ok, I don't have headers, just manifolds, do you think the fuseable link at the starter could be the problem? And the radio is an aftermarket pioneer unit, I sorta think it's something with the faceplate that causes it to cut in and out. On the fuse blowing, what should I do, just trace all the wires that have to do with those lights and looks for shorts or opens? And on that note the PO installed these blue led strip lights under the dash that are on that fuse, could that be overloading it? I thought it would quit blowing if that was the problem though cause I upped the fuse from 15 amps to 25. So where should I start?
 
Oh and the weird thing about the blinker problem is that it only does it when the headlights are turned on, and only sometimes, the blinkers work great when the lights are on and they usually work when the lights are on, although slower than without the lights on... It's just that odd time when I can't use my left blinker cause it's stuck on...
 
Opens make something not work (i.e. no current going through the circuit). A short causes blown fuses because of too much current. LEDs draw almost no current but that doesn't mean that the PO didnt mess something up. Never put in a larger fuse because they keep blowing unless you added something that makes it necessary, that's asking for a fire due to a short. I'd suggest pulling the dash cover off and looking at what the PO did. It may be obvious and you might see something that's charred.
 
The reason I suggested looking at the starter motor wiring first is because you mentioned a problem with a "no starter motor spinning" condition. The starter motor and alternator are major junctions in a wiring system, which provides voltage to the entire system. If a problem exist at one of these two juncture points, it can create problems in the entire system. These are the most common points where problems happen in a wiring system. Anything deeper than that can get pretty technical.
 
Well I just put a new starter in the old girl today, you think I oughta just make sure the starter and alt. Wires are wrapped up nice and out of the way? Or change the starter fuseable link?
 
So are you thinking the short is gonna be under the dash and not back somewhere in the taillight wires? because they are on that fuse, also the park lights are on there too I'm pretty sure.
 
I can't even guess since a short anywhere on the circuit would blow a fuse. Check the simple stuff first like visible wires that may have insulation worn away. Hitting a bump int the road could cause an exposed wire to short and blow the fuse. Then move on to the harder to reach wires. Just guessing at the dash since it's known that someone else messed around in there.
 
Do you guys think that the starter problem when the truck is hot sometimes (I described this in the first post) could be caused by the fuseable link in the wire down by the starter? Like it could be old and going bad or something??
 
Anything is possible,but that scenario is unlikely--usually fusible links fry completely,and if they do allow any current at all to pass through after being fried,its usually not enough to run the many accessories properly,and you'll know it right away...but if you want to replace it while your "in there" its probably not a bad idea, if the wiring is old and original..

The way GM placed the fusible links inside a metal pipe conduit near the hot exhaust manifold often roasts the links and wires inside,allowing them to short out against the metal conduit...on most of my GM trucks and cars,I re-routed the wires that the fusible links are in and ran them directly to the battery positive cable at the battery,instead of at the starter end like it was original(the wires might need to be extended to reach)...then if I ever fried a fusible link it was a lot easier to replace--I cant recall ever having one fail after re-routing the wires...GM used to run the wires that way on older trucks,why they went to that stupid conduit I dont know,it makes more problems than it prevented..



Your neutral safety switch might be slightly out of adjustment,or not letting enough current pass through it,to kick in the starter solenoid after the starter gets heated up from the exhaust--poor connections at the switch or inside of it at the contacts,or where the wire connects to the starter solenoid can make it refuse to crank after it heats up--a hot starter has higher resistance and needs full amperage to get it to crank when its hot..

A ignition switch with bad contacts in the "crank" position can keep the starter from cranking too...sometimes the switch doesn't get enough "travel" to be activated by the rod in the steering colum to fully engage the "crank" position too--this often is the case if the colum was ever apart or someone replaced the lock cylinder,and they didn't line up the little gear teeth just right that operates that rod going to the ignition switch..

A way to test if the starter isn't getting sufficient voltage to the solenoid ,is to jump the terminal at the solenoid with the purple "crank" wire, to the main battery cable stud one next to it,with a screwdriver next time it refuses to crank--if it cranks by jumping it,its the wiring ,not the starter's fault..

I'd make sure the battery cables are in decent condition and are clean and tight where they hook to the battery too..(first thing to check,actually)..
 
Ok thanks, I will try the jumping thing next time it does it. I don't thing the ignition key switch is the problem because it doesn't even work, I have a starter button in my dash. I don't know if that could have something to do with the problem? I definitely need to completely unhook my entire wiring harness and go through it all and replace old wires and just clean it up some though. If I could only find the time...
 
If someone rigged a starter button already,unless they used the original wires,its possible they may have just ran a 12V hot wire to the push button switch,then another wire to the starter solenoid,by-passing the neutral safety switch,so it'll crank in gear as well as park or neutral..if that is the case,you dont have to bother checking the neutral safety switch..

I've had many trucks with old crappy wiring...good thing about many years of GM's is the harness doesn't change all that much,so you usually can find a better one in a junkyard...I've had more than one truck I just replaced one wire at a time,as they failed or got too gangrene...I bought a "rack" that had several spools of different colored wires and matched them the best I could to the OEM colors to help keep things from getting confusing...

I'll say this--nothing is worse than owning a truck some bozo "re-wired" with ALL the same color wires!..takes you forever to figure out which one goes where...I had a few like that..I ended up ripping the harness out and getting another one from a junkyard...
 
Ok guys well I bought some new wire and some loom so I'm going to pull the harness up to the top of the engine bay today and go through it all, clean it all up, replace old wires etc.
 
Ok well I got all the wiring pulled out and I've got 2 wires in my harness that I found that have been cut and just left chilling in the harness... They are both green and both come out of the wire block thing on the firewall below the wiper motor. Anybody got a diagram of that block that shows what the wires are for and where they go??
 
It could be reverse lights too. Dark green and Light green. If the truck was originally a manual truck.
 
It's not reverse lights cause those worn fine and I don't have AC, and I have an afternarket temp gauge cause the stock one doesn't work but the temp gauge just uses a sending unit, no wires correct?
 
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