Tom............disconnect the main power cable from the starter motor and check the unfastened cable end for voltage............should be battery voltage.

Then with the cable off perform a continuity test between the starter motor, where the power cable attaches and frame ground..........if 0 ohms you have found your issue.

 

OK then..the large cable to the starter...must have a dead short. Check the positive cable at the starter...for "continuity" to ground....

 

With the cable disconnected?

 

Guys if the starter cable was a dead short - there would be a dead battery too - very quickly and very much less than 2V!!. The battery test of the ground strap is being done with the hatch open => interior lights are on.... +12v to the interior lights with nowhere to go is 12v on the ground of the whole car. So the ground strap is busted... (or very high resistance anyway)

You need a new one.. do a continuity (resistance check of the ground strap) to confirm this (battery post to the ground of the car) my guess ~ 50 ohms.

This system is so simple it has to be a break in a major connection (either terminal or wiring). I'll bet this groundstrap has been flexed just too many times...

Alan.

 

Thanks for everyone's input. I'm going to check the starter wire tomorrow (with the starter disconnected). If it isn't the starter, at least I have an idea on how to isolate the problem a little better.

Thanks,
John

 

Alan,

I checked the resistance of the ground strap. Disconnected, lug to lug - ~0 ohms. But there was high resistance between the (-) battery and body lug when the ground strap was connected to the battery - 100K ohms.

This is what I know: Battery was purchased yesterday and load checked today - ok. Ran a wire from the starter "big wire" and checked resistance from the battery (+) big wire (disconnected from battery) ~0 ohms. Used the same wire from starter to check resistance to jumper terminal ~0 ohms. Seems like the battery and wires are ok.

But I am clueless how the relays, ignition switch, etc. factor in, but my simplistic view is the starter is the only thing between the battery and the jumper terminal (i.e., battery - big wire - starter - wire - jumper terminal). Wouldn't this say it's either a problem downstream of the jumper terminal, or it's the starter?

 

tomcat...you think its possible, your "brand-new" yesterday battery, could have had the cover installed "backwards" duing assembly ?? If you have 12V from the ngative terminal to the body ground "wingnut"....and 0-2V at the positve cable at the starter, and points thereon....it sure sounds to me like thinga are "***-backwards"....like Alan said...if the Positive cable were shorted to ground, or the starter itself for that matter...you'd have a dead battery in a matter of a few seconds, thats why I thoought possibly the starter was grounded. then it would only drain the battery when the solenoid was engaged. But...from the sound of your descriptions, it sure sounds like your battery is configured where the Negative terminal is 12V+....and the positive terminal is meant for the negative contact to ground....I have never seen such a case, thers always a first for most things anyway...

If you take the negative battery cable off the battery....and check DC voltage from the battery Negative terminal...to the stud for the wingnut...what do you get ???

 

Tomcat...........I just reread your first post to this thread. Everything was fine until you installed the new battery...............can you recharge the old battery, install it or another good battery and see what happens............gotta agree with the 'sounds like somethings up with the new battery' theory.

 

he said his new battery was a Group 49 battery....I just went out and checked my car (its an 86.5) and my new battery is a Grouop 48...think that makes any polarity difference ???

 

Jeff,

I think I double checked the polarity with the voltmeter. I rarely do when checking voltage because I can do complex math (negative to positive) in my head. But this time I made sure red to positive and black to negative when checking the battery voltage. I'm also sure because I took the battery back to Sears today to get the battery checked out. Charged fine at Sears using the terminals as marked.

When the ground strap is removed from the battery (1) with (+) removed = 0V to body grounding pt., (2) with (+) connected = 12.6V to body grounding pt.

I know, really weird. Again, I think I'm correct in saying that when the battery was hooked up to the load tester and charged, bad things would have happened if the poles were reversed?

I still think there is a short to ground. I mean the car is acting like a battery. But if there is no ground, relative ground, would the battery discharge?

 

Sorry tomcat..just trying to help here honestly...as are the other fellows. I do NOT see how its possible...for you to show 12.6VDC to the ground point stud...without the wire "glowing"...and the battery discharging immediately...I'll back off the post, and see if someone (Alan...or the Flying Scot)...can get to the bottom of your malady...sorry I couldn't be of more use...

 

[QUOTE=tomcat]When the ground strap is removed from the battery (1) with (+) removed = 0V to body grounding pt., (2) with (+) connected = 12.6V to body grounding pt.[QUOTE]

Where are you taking thyese readings?...........from the batt (-) negative post to ground?...........which ground?

 

Hey Jeff,

I think my sarcasm may have been intepreted the wrong way. My daily is a Range Rover and I've had my share of problems with it. Always turned out to be pretty simple in hindsight, but the ambiguity searching for the problem can definitly be frustrating.

I really appreciate you guys taking the time and providing input.

 

John....Do you own a set of jumper cables? If you do take one cable and connect one clamp to the wingnut where the ground strap connects to the body near the tool kit. Connect the other end to the - (negative) post on the battery. I am assuming here that you have NO interior lights as well, so when you touch the clamp of the jumper cable to the battery post you may see a small spark as your lights may come on. I am trying to isolate your problem here by starting with your ground strap. By the way, the positive battery terminal should still be connected to the battery when you do the ground strap bypass. Let us know what happens.........Bill

 

No problem tomcat...I just think (in agreement with Malcolm)...that if there wasn't an issue of this magnitude, till the new battery was installed...that there might be the source of the problem. if you have a measured 12.6VDC to the ground stud or wngnut...and 0-2VDC from the other battery post to the same point....the one with the 12.6Volts...IS, and HAS TO BE...the positive terminal, regardless of labeling, or interpretation. I reall would feel better if you were to solve this problem...like I said, I will wait and see if someone is able to help you to a successful fruition of this "gremlin"...glad BTW...you have a car that looks just like mine. Dandeman...and RDS928S both have early 86s that look identical to my ride too