You are here:

Chevrolet Repair/1990 Chevy Scottsdale 357 elecrtical problem

Advertisement


Question
1990 Chevy Scottsdale 4X4, 5.7 90,000 miles

Hello.

Every time I went to start this truck the battery was dead.

Was able to jump start the truck and once it starts it runs pretty well.
Bought a new battery of correct rating.
Problem persisted.

Battery seems to be putting out at about 14
Battery guage indicates it is charging at about 14

Should mention the truck is equiped with a meyer snow plow.
No power is drawn on the plow motor when the truck is shut off and there seem to be no shorts in the plow system.

Figured something was draining the battery even though the truck was turned off - nothing obvious like dome lights, etc.
I put a shut off switch on the ground cables coming off the battery.
That solved the problem for about a week.
Then the battery would be dead again when I went to start the truck (yes, I did remember to switch the ground on again )
So I went back to jumping it each time.
When ground switch is off there seems to be no battery drain, but ...

Today it wouldn't start even with a jump. The engine doesn't turn at all. I get the clicking and the battery drains down.
Even so, the dome light is strong, the plow operates, the key in ignition warning buzzer is loud and clear.

Got Chilton to trouble shoot the problem.
The first check they recommended was to disconnect the positive cables from the battery and test for juice between that and the positive battery pole. Sure enough there is.

Chilton said that means that there is a short in the electrical system that must be remedied before any components can be reliably tested.

Question one:
If I systematically pull fuses from the bank under the dash and re-check for juice between battery positive and disconnected positive cable, and if the test light doesn't turn on, can I assume that the short is in the wiring for whatever that fuse is intended to interrupt?

Question two:
Can I assume that somewhere there is a hot wire that has made contact with a ground wire or the frame of the truck?

Question three:
Am I barking up the wrong tree? If so, are there any obvious places to check or to start in a sytematic way?

Thanks very much in advance to anyone that can help.
Sincerely
Kirk

P.s
It's snowing.

Answer
HI KIRK,OK I GOT YOU QUESTION I WILL ANSWER IT AFTER 6:PM TONIGHT THIS IS GOING TO TAKE SOME TIME TO ANSWER IAM AT WORK SO THIS IS NOT A SIMPLE ANSWER....PS WE ARE GOING TO GET A TON OF SNOW FRIDAY [ROCHESTER NEW YORK]..YIP EEEEE.ONLY KIDDING !!! TALK AT YOU SOON...TOM...

HI AGAIN KIRK,SORRY FOR THE DELAY,OK YOU SAY THAT WHEN JUMPED IT IT WOULD NOT START ??? YOU SAY THERE IS A CLICK ONLY.EVEN WITH THE ELECTRICAL KILL SWITCH TURNED OFF ??? HAVE YOU CHECKED FOR POWER AT THE MAIN POST ON THE STARTER,YOU NEED BATTERY VOLTAGE HERE WHILE CRNAKING SHOULD HAVE JUST UNDER BATTERY VOLTGAE LIKE SAY 11.7 VOLTS OR SO. IF THERE IS GOOD POWER TO THE STARTER THEN THE STARTER IS BAD. NO IF ANDS OR BUTS. BUT LETS SAY THERE IS NOT ENOUGH POWER TO THE STARTER AND YOU KNOW THE BATTERY IS 100 % CHARGED THEN THAT LEAVES ONLY ONE THING BAD CONNECTIONS EITHER AT THE BATTERY CONNECTIONS OR GROUND TO BLOCK, CK THESE AT LET ME KNOW.  TO CK FOR A SHORT IN THE SYSTEM REMOVE YOUR DOME LIGHT FUSE MAKE SURE THAT WHEN THE DOOR IS OPEN THE DOME LIGHT IS OUT. NOW REMOVE THE NEG BATTERY CABLE PUT ONE SIDE OF YOUR TEST LIGHT TO THE CABLE AND THE OTHER TO THE NEG POST OF BATTERY. IF THE TEST LIGHT IS LIT UP THERE IS A DRAIN IN THE SYSTEM. AS YOU SAID REMOVE 1 FUSE AT A TIME AND SEE IF THE TEST LIGHT GOES OUT WHEN ONE OF THESE FUSES ARE PULLED OUT,IF SO THAT CIRCUIT THAT THE FUSE GOES TO IS THE PROBLEM.BUT LETS SAY THAT YOU PULLED ALL OF THE FUSES AND THE TEST LITE IS STILL GLOWING YOU CAN NOW PUT BACK THE DOME LIGHT FUSE AND CLOSE YOUR DOOR AND REMOVE THE WIRING TO THE ALTERNATOR,PCM  ETC UNTILL THIS TEST LIGHT GOES OUT...USUALLY THE PROBLEM IS IN THE FUSE BOX..LETS HOPE..I WOULD NOT ASSUME THAT YOU HAVE A POWER WIRE OR HOT LEAD TOUCHING A GROUND SOMEWHERE THIS WOULD CAUSE A DIRECT SHORT AND WIRES WOULD START TO BURN. THIS IS NOT YOUR PROBLEM. SOMETHING IS STAYING ON WHEN THE KEY IS OFF AND OUT OF THE ING..THIS SHOULD KEEP YOU BUSY FOR A WHILE LET ME KNOW HOW YOU MAKE OUT,,GOOD LUCK,,,TOM

Chevrolet Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


TOM SHEETS

Expertise

PLEASE READ ALL OF THIS BEFORE ASKING ANY QUESTIONS. IF THIS CHEVY SECTION IS MAXED OUT.YOU CAN REACH ME IN THE OLDS/BUICK SECTION. Will answer questions from 6:00am to 10:00pm all days [EST][[[ NO DIESEL OR PAINT QUESTIONS]]] will answer all 1965 to present QUESTIONS ON ALL GM'S on mechanics of these cars. Keep in mind i am not there in person i am going on what you are telling me !! PLEASE IF ASKING A QUESTION GIVE ME AS MUCH INFO AS POSSIBLE. THE MORE THE BETTER. SUCH AS YEAR,MAKE,MODEL,ENGINE SIZE. THIS WILL HELP ME HELP YOU. I will not be able to answer all questions because of some situations that i would really need to be there and see things for myself,such as electrical issues. In many cases i would need wiring diagrams. I can also give you an estimate on what the cost would be at our repair shop as an idea to help you. Keep in mind that my answer is ONLY MY ADVICE,ck with your mechanic as well.. >> THANK YOU, TOM..

Experience

I have been a ASE certified master mechanic for over 30 years and certified IN ALL 8 CATEGORIES,[engine repair,engine performance,auto trans,manual trans,clutches,steering and suspension,brakes,electrical systems,heating and air/cond. I am also a state CERTIFIED inspector for over 30 years. I do computer work [pcm]fault codes,pcm flashing,state inspection monitor readiness,repairs on exhaust,fuel service,[injection and carburetor,] charging system problems, running issues,alignments,frame problems,tire balance,struts and of course standard and anti-lock brakes.

Organizations
nys state auto repair industry and ase group.

Publications
N/A

Education/Credentials
high school,4 years of tech school,and many many hours of auto training with many gm classes and aftermarket training classes..

Awards and Honors
ASE MASTER TECH CERTIFIED IN ALL 8 CATEGORIES.NYS INSP LICENSE AND A/C CERTIFIED

Past/Present Clients
MANY CUSTOMERS IN OUR BUSY SHOP.

©2016 About.com. All rights reserved.