weird problem

[dogdaysunrise]

Hey,

I seem to be having a very strange intermittent problem. My 92 seems to randomly lose ignition for about a split second. My parking brake light comes on and my digital HVAC resets its self. Also the stereo shuts down and turns back on. I found a ground strap loose from the frame and tightened it up, it was the strap at the starter. It seemed to have gone away after that, but just yesterday I was backing my truck into the driveway and when it clunked into reverse it did it again. But for only a split second. Whereas before when the strap was off it was a 5 minute ordeal until I would stop, then as soon as I started moving again it would start again.

I took it out for a drive tonight to see if it would do it again, and it is only doing it for a half second when I would go into reverse. I even put it in 4 and took it through a bumpy ass field. Didnt hesitate once.

Also not sure if this is important info or not, but when the ground strap was off and it was doing it for long periods of time the truck would lose power off the line and sometimes stall. Everytime it stalled however it would crank itself back over.?


HELP! Sorry for the long post, but this ones got me scratchin my head.

 

[ryan22re]

Check all power and ground connections, including the fusible link connections on the firewall.

 

[diesel4me]

short?...

You could have a short in one of the main wires from the fusible links, or the positive battery cable might be rubbing on the hot exhaust manifold and shorting out when the motor moves during shifts from forward to reverse..

A bad ground can do this as well as a short circuit..make sure you have a strap grounding the engine to the sheet metal on the firewall (usually goes on a valve cover bolt factory),and one from the frame to the motor..it could be the big pink or red wire to the HEI losing juice momentarily too,due to corrosion, or a spot thats touching ground where the insulation is worn thru..

Also make 100% sure both battery cables are clean and tight,and no corrosion is inside the cables under the insulation..

I chased a similar problem in my 72 K5 for months,until one day it stalled at a red light,and refused to even crank (it had always fired up again before!)--I finally found the culprit--a former owner chopped off the side post terminals off the battery positive and negative cables,and soldered a top post portion of other cable to it!--and hid it under the battery tray,where I never noticed it for a couple of years!..

I also found the thick red wire to the ignition switch had been butchered,and put back together with a house "wire nut",and it was melted,and shorting out on the metal dash sometimes..it ran a lot better with those issues fixed!..

 

[1985_K5_Silverado]

I chased a similar problem in my 72 K5 for months,until one day it stalled at a red light,and refused to even crank (it had always fired up again before!)--I finally found the culprit--a former owner chopped off the side post terminals off the battery positive and negative cables,and soldered a top post portion of other cable to it!--and hid it under the battery tray,where I never noticed it for a couple of years!..

I also found the thick red wire to the ignition switch had been butchered,and put back together with a house "wire nut",and it was melted,and shorting out on the metal dash sometimes..it ran a lot better with those issues fixed!..

I've found an amazing amount of "they must have been skinflint-cheap to do crap like this" wiring issues over the years. It's like putting a penny in the old house fuse boxes because the fuse keeps blowing, instead of fixing the real problem (but their circuit troubles will soon be over when their house burns to the ground).

 

[diesel4me]

me too...

I've seen my share of ghetto fab wiring fixes too!..like whem someone wraps aluminum foil from a bubble gum wrapper or ciggarrette pack around a fuse,so they can avoid fixing the real problem-(or are hoping it burns to the ground,so they can collect the insurance!)..

I don't understand why someone would bother cutting off a foot of a battery cable,and solder a one foot hunk off another just to have top posts!--why not BUY a new cable for ten bucks?...they probably spent all of that on solder,flux,and a propane torch!.. .

I don't see what the big "mystery" is when it comes to electicity or wiring..its no more complex than anything else is,its just that people make it seem like it is..whats so hard about cutting out a bad length of wire,and splicing in a new peice properly??..or measuring voltage?...

Or, instead of condemming a starter or alternator immediately when problems arise,when 90% of the time its a wire or switch problem,and not the starter or alternator!..
I have about 6 alternators out in my shop,that friends replaced because they were "junk"--but the only real problem was the wiring harness in their trucks wasn't giving 12V to the feild terminal,and they didn't learn this until the battery croaked with the NEW alternator a few days later!...I'm the proud owner of several "good used" alternators now!..have about a dozen "junk" starters too,most of them only need a new starter solenoid or drive..

 

[dogdaysunrise]

i think the biggest thing with wiring issues is that there are so many things that it could be. Plus they are hard to diagnose and pin point.

As far as whats going on with my truck, im thinking its the ground cable from my battery (-) post to the body of the truck. I noticed today that my voltmeter was bouncing between 12.5 to 14 volts. Whenever I hit a good bump or gunned it to get the alt spinning a little faster the voltage would come up. It would always bounce around though. If I just turn it to ignition the voltmeter would sit at a constant 12v like its supposed to, so im pretty sure its not the meter.

 

[diesel4me]

Fords are worse!..

It seems Fords have way more electrical issues than most other vehicles...my friend gets all the winners--he spent about 6 hrs chasing a weird problem on an older Ford LTD..its alarm would howl constantly,but not at 100% volume!--you could hear it,but it was very muffled and sounded like the alarm itself had fried..we couldn't get the car to start either,it had been towed in!..

We spent the entire day removing all the alarm wires,only to find it still had no power to about 1/2 of all the fuses in the box under the dash--still would no start--and even with all the under-dash wiring going to the alarm box disconnected--it STILL was making noises!.. --we were beginning to think it was haunted!...

After a few hours of poking wires with test lamps,and scratching our heads,we finally found a thick wire that goes behind the radiator and across to the other side of the car was rotted in one spot!..took about 30 seconds to splice it,and everything went back to "normal!"...drove us ****in crazy!..then the owner sneaks the car home that night without paying the bill--he thought 60 bucks for diagnosis and labor was "rape"..I don't think he paid him to this day!..and he admitted "the car runs 100% better than it ever has" too!..

I'd start your motor,and go under the hood,and start grabbing wire harnesses and shake them--most of the time I find corroded wires or plug connections this way..if you get lucky the motor will stumble or stall when the wire causing the dilema is shaked or disturbed..

On many Fords,I've had to chop out the male/female plugs and splice the wires together in order to restore power to the computer or distributor many times..often these kinds of problems are worse after its warms up,or on rainy damp days...the car runs great for awhile when cold--then quits..but after cooling down awhile,it starts right up again,when the corroded connection cools down and makes a contact again..somtimes it wont do it for days!.

I believe a good many decent vehicles with wiring problems get junked,rather than fixed,because shops charge so much for diagnosis and labor..most folks feel a 20 year old vehicle just ain't worth it--but 25 cents worth of new wire and some tape would fix most of them once the bad wire is found!...