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Battery drain after turning engine over

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jjbunn

jjbunn

Jedi Knight
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I tried to start the TR6 today (it's been sitting for a couple of months while I've been doing various jobs on it). The engine turned over a couple of times, and then everything went dead. Battery voltage is 14V until I put the ignition in the "run" position, at which point it drops to 0.5V or so ... indicating to me that there is a short. Is the starter motor kaput?

How should I go about diagnosing this problem?
 
Julian,

Look for the obvious.

I'd go get the battery fully charged before I tried
anything else. You might have 14v but no push behind
them.

d
 
Almost certainly a "long" rather than a short /bcforum/images/%%GRAEMLIN_URL%%/grin.gif

Lots of places to look, but IMO the most likely is the battery clamps themselves. If you can test directly on the tops of the posts and see it drop to 0.5v, then the battery is bad.
 
ALWAYS check all the major power connections for corrosion, etc., before panicking! Randall's probably right, although it can be on the other end of either battery cable.

Please do NOT ask me how I recently relearned this lesson...on my daughter's Mazda B3000 pickup. /bcforum/images/%%GRAEMLIN_URL%%/frown.gif
 
While I was removing the fenders on my TR3, I disconnected the battery. When I laid the cable end over the terminal and tried to start it, the same thing happened. It was the poor connection at the battery.
 
Do you know the batery's heritage or did it come with the car when you got it?
Chances are it's a marginal battery.
 
Checking to make sure ALL connections are clean and tight is the first thing to try. An Idle battery can and usualy will develope corrosion in and on the connections.
Testing the voltage doesn`t say much. It`s the cranking amperage that counts. I suggest first charging your battery fully. Then take it to any autoparts supplier IE. Autozone, Checker A.P., N.A.P.A. ETC. They will test it for you {Normaly free}. Even a marginal battery will test at normal or near normal voltage but may not have the cranking amperage that it takes to turn an engine over more than a couple of turns.
A marginal battery can and usualy does drian down {amperage wise} during peroids of idleness. Resulting in what one might mistake as a closed or short circut. The age of a battery says a lot about it`s condition. If it is near the end of it`s life cycle {a four year battery that is 3 years 11 months old} I suspect it is Marginal at best.
Just my .02 pence worth
Kerry
 
Thanks for all the advice. I don't know the age of the battery. It *looks* new-ish. It is quite a bit smaller than the tray would allow, and looks smaller than the batteries I'm used to. I'll charge it up before panicking /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

What type/size of battery do people recommend for a TR6 if I replace it?
 
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