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MG TD TF 1500 - Dead Battery - OT (But Maybe Not Really)

I had this problem years back with the TR-4 and now I'm having it with my '77 F-100 and I don't want to have it with the TD. The truck gets driven maybe once a month and it usually starts right up (manual choke - cranks a few seconds and fires up)

Recently, however, it has frequesntly acted like the battery is dead (slow grinding of the starter motor and then nothing). Twice I've put the charger on it, charged it up, started it and taken off to Auto-Parts-R-Us for a new battery. Both times they've checked the battery and (they say) the charging system and just looked at me and said "How often do yoou drive this?" When I tell them they say "Well, you just have to drive it more often - the battery is still good and the charging system is checking out good (14.5 volts or thereabouts)."

So, took off this morning to go ~ 100 miles to Columbia. It started fine but about 15 miles down the road when I stopped for gas it wouldn't restart - dead battery (or so it seemed). Got a jump and got it restarted and finished the trip. Sorry for such a long intro but here's the question:

If the charging system isn't working and the battery was dead I shouldn't have been able to finish the trip should I?

If that's the case maybe the charging system is working and maybe the battery is OK but then (here's where y'all's experience will be helpful) what else would cause these symptoms?

Thanks.

Jud
J K Chapin

Jud
I'd start by cleaning the Battery Posts and Connectors
and put some dielectric grease on them.
Mike R
m renton

Jud,
I agree, but carry it a bit farther, the cables to the starter switch (solenoid in this case) and to the starter. (solenoid might be mounted on the starter for this one? so no cable there.)
Al
54 TF "Emma"
A W Parker

Most importantly - check the earth strap from the engine to the chassis, and from the chassis to the body, and from the body to the battery.

You need a really good earth for the starter !.

90% of electrical problem in MG's are related to the earthing side ! - so the legend goes !.

Tony
Down Under
A L SLATTERY

I agree with the suggestions but my buddy (the expert shadetree mechanic (he really does know a lot about that vintage engines but, he'll not admit it, I probably know more about electricity - in theory at least - engineering degree, worked thru college as an electrician etc.) wants to replace the alternator. I don't see how you can drive 85 - 90 miles on a dead battery if the alternator is not working. We'll see what happens this Sunday - Saturday is a show (Highland Games and "Great Scot" car show at Furman - anybody going?) so Sunday will be the "work" day.
Jud
J K Chapin

Jud - First check the battery voltage when the engine is running at a high enough RPM for the alternator to be putting out a good charge. The battery voltage should be at least 14.3 volts. If it isn't at least that voltage, you need a new alternator. Second - invest in a Battery Tender/battery conditioner/Battery Buddy - they come under several different names and will keep a battery in good condition when it is not in use. These devices are not just a trickle charger (which will over charge your battery over a long period of time), the will charge the battery up to the upper limit, then shut off, allowing the battery voltage to drop to a lower limit, the start the cycle over again. This keeps the battery in good condition and will prevent the plates from developing a coating of sulphate on the surfaces (which is probably what has happened to your battery already). Cheers - Dave
David DuBois

Jud - Should have started my last post with - After checking the cable connections to the battery and the ground connections to the chassis as suggested by Mike R. then Check battery voltage when the engine is running... Cheers - Dave
David DuBois

Jud

Posts are on the right track, check all your earth paths and connections to the battery posts. I just experienced like symptoms using "jumper leads" all lights lit on the dash however could not get the starter to reach full revolutions when cranking the engine, burnt terminations in the "jumper leads" clamps were the problem.

Graeme

G Evans

JUD,
Do you have one of those battery shut off switches with the green twist knob on it????? The ones that can get pitted and and act like a bad terminal connection?????
I threw all of mine away!!!!!!!!!!!!!
SPW
STEVE WINCZE

Dave, is this the type of charger you endorse using? It appears to have the ability to charge through a cigarette lighter, which seems like a convenient feature.

http://www.walmart.com/ip/Black-Decker-Black-Decker-Battery-Maintainer/21721663?findingMethod=rr#Product+Reviews

Corey Pedersen 1951 TD #7169

Steve, I don't have the green knob switch but I have a brass knife switch that I haven't installed yet (kind of clunky but looks very robust).

Corey, subject to hearing from Dave I'm on my way to the local Walmart - thanks.

Graeme, I think you and others are on the right track - bad ground circuit. I've discovered some rusted panels that I'm replacing and I suspect that there may be rust where a ground strap connects the frame to the block so I'll check and clean the connections.

Thanks.

Jud
J K Chapin

"Dave, is this the type of charger you endorse using?"
Yes, that will do the job. Cheers - Dave
David DuBois

This thread was discussed between 20/05/2013 and 21/05/2013

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