Dead Battery ?

[54blackhornet]

Brand new battery. Went to start the 71 C/20 , nothing. checked to see if I left anything on, ignition switch off. Heater fan off, headlights off ? Battery has 1.9 volts....any ideas ?

[Steeveedee]

Start charging the battery. After a bit, see if the alternator is warm. That would mean that it has a shorted diode. I got two of them before I got a good one. If so, disconnect the battery from the system to finish charging it.

[72c20customcamper]

First off you need to charge the battery then see if there is a drain on it with a multimeter. Hook it up and see if there is a draw if so then start pulling fuses one at time while checking the meter . Helps if you run long leads so the meter is visable as you pull them

[54blackhornet]

Thanks fellas ! I worked on the horn button last weekend, wondering if it was possible that the relay stuck on ? I just returned from NAPA , they charged the battery for me. Will report back after I figure it out...Jack

[shorty402]

Had the same issue. Stuck horn relay.

[purple gas]

If your trouble started right after installing the new battery it's not impossible you bought a dud.
A few years ago I bought a brand new battery. I was constantly having to charge it. Checked a crap load of possible problems.
I finally got pissed off and bought another battery. Never had an issue since.
Truck sits 5 months outside in cold Canadian winters. In spring it fires right up.

[54blackhornet]

The battery was fine for weeks after I bought it. I got it recharged yesterday At Napa and reconnected it. Started right up. I would like to check for parasitic draw but unsure exactly how to do it. I have a dmm but was told I could ruin it if you don’t hook it up properly....thoughts ?

[body bolt]

Originally Posted by 54blackhornet

The battery was fine for weeks after I bought it. I got it recharged yesterday At Napa and reconnected it. Started right up. I would like to check for parasitic draw but unsure exactly how to do it. I have a dmm but was told I could ruin it if you don’t hook it up properly....thoughts ?

What's your max current rating on your meter? It's usually right on the front between the two jacks used for current. It's probably at least 10 amps. If so set your meter for current in 'amps' then connect one of those leads to the battery and the other to the cable. Polarity doesn't matter.

[54blackhornet]

Thanks I appreciate your help..Jack

[cj847]

There are tutorials on parasitic draw on line and on youtube. But basically check the draw at the battery with key off. If you have a problem, you can find what circuit it is on by pulling fuses one by one until it goes away. Good luck.

[dmjlambert]

Originally Posted by 54blackhornet

Thanks fellas ! I worked on the horn button last weekend, wondering if it was possible that the relay stuck on ? I just returned from NAPA , they charged the battery for me. Will report back after I figure it out...Jack

Before you get too involved and a multimeter and all that jazz,... So you were working in the area of the horn button. If the horn relay were stuck on, that would sure drain your battery. The horn would be blaring, if you have a horn. Do you have a horn relay and no horn or disconnected horn?

[Stocker]

You don't even need a multimeter. A 12vdc test light can check for battery on the green wire that connects to the horn(s). If you see voltage there, the horn relay is stuck on.

[RichardJ]

>> I would like to check for parasitic draw but unsure exactly how to do it.<<

Connect the +(Plus) battery cable to the battery.
Touching the -(Neg) battery cable to the battery should produce little to no spark. A very small spark from a radio memory connection (radio OFF) would be considered a small parasitic drain. the larger the spark, the larger the drain. Not very accurate, but incredibly reliable.

That said, not all battery drains are constant. Some are intermittent and impossible to detect with a digital meter. Digital meters Sample, Display, Pause, Repeat. Digital meters tend to jump around and it isn't always easy to see if your connection is the problem or if the intermittent problem is part of the problem.

A bad power antenna with a internal self resetting circuit breaker would drain a battery in four days, had me stumped.
A Analog Ammeter connecting the battery cable to the battery is the best way to check for battery drain. After that antenna problem. i won't use anything else for a battery drain problem. Three digital meters could not show me what that 80 year old Instrument Panel Analog Meter could see.

[54blackhornet]

Thanks guys ! I determined it was the horn relay stuck. I didn’t have the green wire connected to the horn so no indication the horn push components where not in the right orientation. I do like the idea of using the amp gauge instead of the DMM, pretty cool idea...back to splitting firewood...thanks..