Small electrical short?

[sony2001]

On a K car there is a small short. With ohm meter wire on 15V and other on 150ma the needle reads 10 when I bridge the -battery pole and the -cable unattached to the pole. Touch the elec. door locks and the needle goes up to 13. The only time the meter drops to 0 is if I unclip the red wire that goes to the + of the battery. Is that 10 volt discharge or is it 100ma? I removed all fuses and still had the discharge.

 

[ebbtide176]

Re: Small electrical short?

from what i understand with your post, yes 100mA. what problems are you having? battery going dead overnight? or just after a few days with no startups?

 

[sony2001]

Re: Small electrical short?

I eliminated a bigger short by changing the door switch below the hinge. This remaining short causes the battery drop below starting level in 2-3 weeks. The smaller cable from + battery is red and has a slide disconnect. It's probably for the car interiors and the short travels along this wire. But what would have a 100ma drain? Computer? clock? Sensor? I guess each connector should be opened to see if the short stops. Thanks ebb.

 

[sony2001]

Re: Small electrical short?

Yesterday the battery had a full charge and only the bendix would engage. Could the starter have a continuous short?

 

[bubbakat]

Re: Small electrical short?

SONY yes it could. had one in wifes car like to have worred me to death. Decided to take starter off and take to rebuild shop and they found the prob.

 

[sony2001]

Re: Small electrical short?

Thanks bub. It's the LeBaron turbo, convertible,all white, retro cheap thrill, that stalled in a sector of the city where everyone's designer clothes has Harley Davidson written on it. Turned out everyone was very nice and wanted to help. Guess the car might miss the F1 next weekend. That will kick off the party time here for the next two months.

 

[ebbtide176]

Re: Small electrical short?

100mA=1/10thAmp not much to me. you might do a search on user 'schematic' for details as to what current amt will cause problems. <br /><br />has the battery been load-tested? as far as the starting problem, a bad battery, or even loose post connections can cause that. it seems to be a low voltage at the starter. but a worn out starter can also cause it, if the brushes are not contacting(in the starter). even a worn out solenoid will do that when the internal contacts are worn down. i think that Kcar solenoid has the type of internal contacts that can be pulled off stud and 'flipped' over.. <br /><br />often, the problem of a short-circuit killing the battery numerous times ends with a bad battery in addition to the root cause.<br /><br />just a thought

 

[Paul Moir]

Re: Small electrical short?

100 ma will drop a 85 minute reserve capacity (RC) car battery to below starting in almost exactly 2 weeks: <br /><br />RC = How many minutes a battery will supply 25A and not drop below 10.5v (Can't turn over most engines at under 10.5v.)<br />RC/60*25 = Amp Hours (35.4Ah for a 85 min)<br />Ah/drain = Hours (354 hours for a 0.1A drain)<br /><br />354 hours is about 14 days (354/24 = 14.75).

 

[sony2001]

Re: Small electrical short?

Found a loose bolt on the selonoid and a second less loose. I now cary a second battery as additional help. While trying out the latest fix I'm now on the trail of the starter relay. When I find it I'll check it out will the aid of the elec. shop manual from Chrysler. Their short test for a starter states that an over 200 ohm leak is OK but a less than 200 ohm leak is NOT. Oh!!!!

 

[sony2001]

Re: Small electrical short?

Well guys thank you very much. Ten starts and no problem. The starter even feels its turning with a full supply of juice. These compound problems, courtesy light short and loose starter cable, are quite the challenge, but the reward is sweeter.

 

[sony2001]

Re: Small electrical short?

Went for a ride down to the Grande Prix F1, convertible down and getting into the beat of the lead up to the race. Well when night riding, lights on, heater fan,and traffic the led for the charging went from 12v down to 8v, lights were dimming. Over 30 minutes the battery went dead and occasionally reving the engine got a 12v charge. Power loss light was flashing and near the house engine quit. In the morning boosted it and it ran fine. I'm now cleaning the alternator connections,and looking at battery temp sensor, carbon pile rheostat ?, logic module. Two down, one to go. Can anyone venture a hunch?

 

[ebbtide176]

Re: Small electrical short?

if this is still the Kcar, and you've replaced and/or load tested the battery, then its time to get the alternator output checked. <br />-that's another common fatality of loose connections/bad battery. <br /><br />or you didn't replace/load test the battery, and its bad, and caused the alternator to suffer. just my thoughts... if, in a Kcar, the alternator checks out but the regulator is wacky, i think that regulator is built into the onboard computer. that is pricey, but can be bypassed with an external mopar $12 unit...(last time i did it)<br /><br />sounds like you've almost got it whipped now

 

[sony2001]

Re: Small electrical short?

So far I've cleaned the alternator contacts and tried to recreate the power loss situation. Everything checked out. Thats enough for this year on that car. The weather is breaking into full summer. Its boating time and find a spouse time before the onset of fall.

 

[sony2001]

Re: Small electrical short?

Well went night riding and the no charge below 2000 rpm returned. Drained the battery in minutes. Boy I used to think Lucas electrics were bad. Called them the Prince of Darkness. This logic module is a Baron of Blackout. Will have to go the external regulator route.

 

[DJ]

Re: Small electrical short?

Sony,<br /><br />Is your alternator diode bridge shorted? That will diminish output (2/3) and could cause a draw.<br /><br />Anybody know the three positions of a Lucas light switch?<br /><br />1. Dim.<br /><br />2. Flicker.<br /><br />3. Off.<br /><br />