Electrical draw issue

-
1

1974stepside

Member
Joined
Feb 17, 2010
Messages
20
Reaction score
0
Went away for two weeks and came back the battery was dead. before I went away everything worked fine, I came back replaced with brand new battery it starts and runs fine but the tailights do not work.

Turn the key to on position without starting and the headlights and front indicators work, apply the brake or put in reverse and they stop working. when applying the brakes on their own they are very faint, If I put in reverse the brake lights come on very faint.

Any thoughts? I tried tracing some of the wires to see if they were wore down and rubbing on metal but no luck.
 
How well do the turn signals work? Might be a bad ground in the rear. Does the truck have a amp meter on the dash?
 
They were working fine, now the rear doesnt work. I dont the the amp guage ever worked.
 
It sounds like you have either a ground issue or other open wiring somewhere. Check your bulkhead connections and/or ammeter wires too.
 
Grounding issue on the taillights! I had to solder the bulb sockets to the taillight housings on my 78 pick-up to get a good ground.
 
Start at the bulkhead, and then ammeter, checking voltage/ohms the whole way. Check across the ammeter. bet is; those 2, or , how much charge is going into battery?
 
Some times life is just a :banghead: when it comes to old auto electrical issues. You could end up running around in circles if the problem is not completely corrected. I would bet all you need is a volt meter and time to find your problem/s: (even though your lights are acting up) Firstly as stated pull out all your rear lights one at a time and ensure the sockets are clean and they have good grounds.
My suggestion is that you first set your car up so all the conditions are "off" IE lights, radio, doors closed etc. At this state your vehicles battery should show no power loss or leaks to ground in a "corrected" condition. Anyways, put your volt meter to the DC volts reading....disconnect your negitive cable from the battery and meter between the neg cable and neg battery pole. If your meter shows any voltage or reading. this surely indicates something is grounded and slowly draining your battery.
Eight times out of ten a battery drain problem comes from your fuse box runs on the BATT side of things. (like a trunk light left on). Your Assisories or Start circut side of the fuse box runs could be OK.
Next, find your fuse box and have someone watch your meter as you lift one fuse at a time...(make sure your door is closed or the door button pushed in so conditions are correct and your using no power)..When, the correct fuse is pulled for that grounded run the meter should now show "no" voltage being used at the meter.... if this is the case, it will put you at a starting point. Some fuse boxes have the names of the componates on them IE lights, brakes, lighter etc. From there you will have to get some electrical drawings that show your electical runs. I hope some of this helps to get you on track. PS..I had a problem once where my trunk light adjustment button was out....It was hard to figure the problem out as the light was on with the lid closed lol.
 
You MAY have TWO different and possibly unrelated troubles

FIRST THE "DRAW"

You may have an electrical "draw" or you may have a battery going flakey

Charge up the battery and have it tested by someone with a REAL "load tester." A 'real' load tester is NOT the size of a "pocket meter" but rather more the "size of a breadbox."

Next, leave either the hot or ground cable off the battery, and put your test lamp (you do have one?) in series. That is, if you leave the ground cable off, hook the test lamp from the engine block to the battery neg. post

IF YOU HAVE NO DRAW it will not light. Check in "in the shade" preferably in the garage, and look for the lamp to glow.

For the above test, make sure all 12V loads are off--dome lamp, glovebox/ center console, map light, UNDERHOOD LIGHT, trunk light, etc

If the lamp lights or glows, pull fuses one at a time until it goes out.

If it won't go out with fuses pulled, you'll have to get a bit creative. Remove the main alternator wire--the largest one hooked to the big stud.

So far as your tail lamp problem, this sounds like the classic lamp socket ground problem.

Pull the lamps/ sockets, clean them, if necessary solder a wire pigtail to them so you can hook a wire to the body for a ground.
 
It seems when I drive that the brake lights and indicators work or dont work, then I guess I hit a bump and they stop working or start working. This has been a real PITA, I will try metering between the negative battery post and cable, then I will try doing the draw test with my test light. Thanks.
 
I tested for the electrical draw metering between the neg post and cable and there isnt any, I tested by opening the door so the dome light went on.

There is a lot of splices in the wire due to cables melted together, could that cause this? I would like to test the tailights to make sure they are getting the right amoutn of current, anyone know what I should look for?
 
RESOLVED

This was the taillight ground. Once I grounded it the reverse, rear indicator, brake and taillights started working again.

Thanks all.
 
there is a situation that occurs when, if memory serves me,, where if the four way flasher, radio, turn signal, foot on the brake, and a couple of other accesories, are on,, the radio etc will get power thru the 4-way, and radio and all will go on/off with flasher,(no key needed) .. bottom line, make sure 4 way flasher is off,, it can drain through there if the flasher unit is faulty... I'm thinking the 4-way is on,, and not working,, draining the batt... good luck.. grant..

Just re-read original post,, disregard.. sorry... grant
 
Sorry for the mini hi-jack but is there any truth to what I have been told that on a vehicle with a computer you should not disconnect the - cable and put a test light between the battery and the cable end in an attempt to trouble shoot a draw on the battery?? Don't remember the reason just someone telling me the above.....
 
I would say "maybe." On the two Rangers I own, the only drawback to disconnecting the battery is that the computer "takes a few miles" to reteach itself.

I've heard horror stories about some GM owners something about security and the radio?? But when I got my 95 Olds from my Mom, the battery had gone dead/ bad and sat for a couple of weeks or more. It suffered no ill effects.
 
You must log in or register to reply here.
-

Back
Top