|11-03-2012 07:16 AM|
At first I thought you were describing an ignition switch problem, but now it sounds more like a simple power problem.
- If you can't get power to the headlights you have a basic power problem and there is a wire or junction that is flaky.
- If its only a problem with power that runs through the ignition switch, then you may have a bad column switch or the rack and rod is shot. The electrical switch is mounted low on the column where its fairly easy to reach. The ignition lock cylinder has a toothed rack and rod mechanism that connects it to the electrical switch on the lower column. You can reach all the electrical wires for the ignition at the connector on the lower column.
Since you have overall loss of power I would check wire junctions and fusible links.
- First check - On my '75 GMC I used to have random problems with loosening of the connection at the starter where the main battery cable is connected to the truck wiring. This bolt and nut connection is exposed to road dirt and you have to crawl under the truck to check it. However, if that bolt is corroded or the nut loosens up you lose all power because that is where the truck's main power feed connects. Make sure it has a star washer, and maybe an extra lock washer to keep the connection tight.
- Another point to check is the fusible link at terminal post on the firewall next to the brake booster (toward passenger side). The main power wire with the fusible link goes straight down from that junction and you should be able to feel the soft fusible area. It can burn partially away inside the wire without burning the wire completely off. Parts stores sell a replacement GM fusible link in the Dorman or Help! parts area. I believe its a 10 gauge wire with a 14 gauge fusible link.
- There are also two fusible links at the starter post connection. One is in the wire to the alternator and the other is in the power wire for the rest of the truck.
- In addition, the three small wires connected to the starter junction (two wires above, plus solenoid wire) run through a metal tube on the back side of the engine and if this tube is out of place it lets them get too close to the exhaust. They could have fried together or grounded to the tube.
|11-02-2012 06:39 PM|
|cobalt327||Some good basic info and links, courtesy of the Crankshaft Coalition wiki: Troubleshooting electrical problems|
|11-02-2012 04:09 PM|
Eliminate the basic stuff.
Remove the battery cables from the battery and clean them and the battery posts. Reinstall.
When the system is dead do you have voltage at the battery terminals? Test light will do.
Have the battery load tested at Autostore.
Also, sometime the lugs on the battery cables are corroded internally and make an intermittent connection to the wire. Replace the battery cables.
Check if the grounding jumpers are installed, connections must be clean and tight. Grounding jumpers are frame to engine and frame to body.
|11-02-2012 01:50 AM|
|theguesswho||running lights wont come on and head lights wont come on, no radio no wipers no nothing, when i put the key in and turn it to the on position not a thing happends. the steering coloum thats in it everything works fine on it the ignition is fine i know that and its all wired up right, i didnt see no burnt or corroded wires or anything when i was installing it, like i said for some reason when i went out the next day it was working so i wired everything up and i fired up the truck a few times, and then like 5 hours later my buddys wanted to see the fancy lights on it and i turned the key to the on position and when i pulled out the light switch to turn on the running lights everything died right away, and id turn the ignition forward and the oil and gen light would light up but try turning on the running lights or wipers and the power would get cut, and now for some reason the oil and gen light wont come on now, i dont understand it becuz tomorrow i could walk out to it and everything might work fine again, thats whats been happening, the truck doesnt move around or anything, i still have to put the box back on it, its been in the same spot for the past 2 weeks, one day it will work fine and the next ill go to turn on the lights or start it and my power will get cut, if i leave it , it seems to suddenly work after letting it sit over night or something thats how its been going, everytime this has happend, id just leave it for the next day cuz i get pissed off at it, and the next day id come out and everything would suddenly work, the most iv gone without it working was like 2 or 3 days then it suddenly came back, i could turn the key in the on position 100 times befor it screws up again or only 3 times befor it screw up again, it works when it wants it seems, witch makes it more hard to figure out what the problem is|
|11-01-2012 09:06 PM|
First is the ignition switch. It's bolted to the steering column under the dash area. The wiring may be loose or burned, or the switch could be out of adjustment, or worn out.
The other thing is the neutral safety switch. This could be the problem if you get normal operation after you jiggle the shifter or put it into Neutral instead of Park. If its that, the dash lights, etc. will still come on w/the key, but the engine won't turn over.
|11-01-2012 02:40 PM|
The 1973 - 1987 Chevrolet & GMC Pickups Message Board - The 1947 - Present Chevrolet & GMC Truck Message Board Network
^^^^^^^^^link to the 73-87 section..
|11-01-2012 02:38 PM|
I'm not sure about the 73 up trucks..
my truck the one wire that powers the cab.. goes from the battery(p****ide) across the coresupport(radator) and to the voltage regulator(behind drivers side headlights, then toward the cab bulk head connector..
I'd copy and paste your question here
The 1947 - Present Chevrolet & GMC Truck Message Board Network - Powered by 67-72chevytrucks.com
in the 73-87 truck section..
and you'll get people that have seen the normal problem areas in those trucks..
where the fuseable link is (mine is on pass side fender) if you shorted out something you could take it out.. and it can come and go..
|11-01-2012 02:28 PM|
|theguesswho||so i went back out the next day after leaving the steering coloum on the floor of the truck still wired up and everything, and the next day i went out and i turned the key and everything works perfectly fine, the truck didnt move no body messed around with the wires or anything, i dont know what the hell s going on, the truck just sat there over night and the next day everything was fine, a main wire clip/conecter on the steering coloum from the 79 didnt match up to the one from the 74 truck every other connecter did, but one didnt and i kinda mashed it together and forced it in, so i thought maybe when i slammed the door a connetion got made, so i cut off both connecters and taped the wires together one at a time and wired everything up and put everything back together and it was working perfectly fine now and about 5 hours later i was with my friends and they wanted to see all the lights on the truck light up at night cuz it has 2 lights under the bumper and 5 lights on the roof like a big 18 wheeler, so i went to the back where the truck is and i turned the key forward in the on position and pulled out the light switch to turn on the running lights the lights didnt even get a chance to light up befor the power got cut again, the light up for a split second and now its happend again, i dont under stand this at all, today i unbolted the fuse box to see if there was any back connections or anything beheind it, nope everything looked fine and was connected fine, i looked under the hood and uplugged any wire connetions that i could see and if they were rusted or correted i leaned them up with some sand paper and liquid wrench, i only found one bad connection that was pretty rusted, but i leaned it up and doesnt look like it was the problem, i googled this problem and i found alot of pages about some fusable link somwhere? and my dads friend said somthing about a relay, i dont know what that is or does , any idea's?|
|10-30-2012 05:28 PM|
|poncho62||Sounds to me you have a loose connection somewhere....When you stomped your foot on the floor and it fixed it, you likely made the connection. First thing I would check is the back of the fuse box where all the wires come through the firewall....In the middle of the block on the firewall side is a bolt that holds the 2 sides together. See if that bolt is tight.|
|10-30-2012 04:24 PM|
74 chevy c10 ignitiont no power PLEASE HELP!
hi im a rookie car guy im 19 i know this is VERY long but please take 5 mins of your time to read this and help out a poor kid and i dont know a dam thing about electronic stuff by the way so thats why im here, i just bought a 74 chevy c10 that came with a 79 silverado parts truck, but for the 74 when i got it in my yard the lights would always come on and it would fre up and everything and about a week later i was hooking up a tape deck i was being gentel i wasnt yanking on all sorts of wires or anything and i went to turn the ignition foward so i could see if i hooked up the tapedeck right and nothing happend, no power came on no lights nothing as if the battery wasnt even hooked up to the truck, i didnt know what happend, i sat there for a few mins and i turned the ignition foward again and everythinhg came on, and then a few days later it happend again but this time it didnt come back so i got pissed off and slammed my foot on the floor and a few mins later it was working again and it worked for a couple more days and then it happend again but this time stomping my foot on the floor or giving the dashboard a tap with my hand didnt do anything, but now today when i turn the key forward in the on position the oil and gen light would come on, and if i tried pulling the light switch out for running lights or anything the oil and gen light would go right off and id have no power, so id turn the key back and forward again and thoes 2 lights would come on but try and start it, and nothing just dead silence, the guy i bought the truck off of mentioned somthing was wrong with the stering coloum, cuz it could only be in one position(tilt steering) inorder to turn the key and it was working aslong as it was in that one position so i didnt mind, but i thought maybe the ignition is so screwed up now, it wont even give power to the truck, my dad took a screw driver to the starter and got a spark and said your battery and grounds up here are good maybe its the ignition, so i took out the steering colum from the 79 silverado witch works fine, so both trucks have the steering coloums removed as of right now and i wanted to see if my problem was fixed befor i bolted the 79 silverado coloum all up, so i rested the steering coloum on the floor of the truck and i wired everything up right and still nothing, not a thing, the oil and gen light dont even come on now anybody got any idea's? the only thing i can think of is a ground somewhere, but i dont know where to begin looking for ground wires, i dont even know how many ground wires there are in a vehicle, and i dont have money for any fancy electronic tools that you touch wires with that tell you whats working and whats not, i bought this truck for 200$ for somthing to bomb around in for the winter, so i need a cheap easy fix, help me please cuz there's nothing more i can do