Power Draw

Gotta love that wiring . . .
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davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Power Draw

Post by davery »

I have my dash board partially apart and am having issues with the battery maintaining a charge. Does anyone know if there would be a power draw if something is not connected in the dash? Currently I do not have the speedo, tach, courtesy light or clock installed. Could one of these create a power draw if they were not connected? Thanks.
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
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RRoller123
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Posts: 8179
Joined: Sun Nov 13, 2011 2:04 pm
Your car is a: 1980 FI SPIDER 2000
Location: SAGAMORE BEACH, MA USA

Re: Power Draw

Post by RRoller123 »

It could be the battery itself. Have you had it tested at the local parts store?
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
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divace73
Posts: 1380
Joined: Sun Oct 17, 2010 5:59 am
Your car is a: 1980 Fiat 124 Spider Silver
Location: Sydney, Australia

Re: Power Draw

Post by divace73 »

davery wrote:I have my dash board partially apart and am having issues with the battery maintaining a charge. Does anyone know if there would be a power draw if something is not connected in the dash? Currently I do not have the speedo, tach, courtesy light or clock installed. Could one of these create a power draw if they were not connected? Thanks.
If the battery is not maintaining charge it could be the alternator or the battery as RRoller123 has suggested. With the engine running the voltage on the battery should be around 13.8 volts

To measure current leak, Use a multi-meter set on current and put it inline to the battery to measure the current draw, take note what the draw is. Then go to each circuit and do the same thing, it will limit to where to start looking.
Cheers David
-=1980 silver Fiat 124 Spider=-
If you want to see pics of my car (and other random stuff) >>click here<< OR
see my >>You tube channel<<
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Power Draw

Post by davery »

divace73 wrote:
davery wrote:I have my dash board partially apart and am having issues with the battery maintaining a charge. Does anyone know if there would be a power draw if something is not connected in the dash? Currently I do not have the speedo, tach, courtesy light or clock installed. Could one of these create a power draw if they were not connected? Thanks.
If the battery is not maintaining charge it could be the alternator or the battery as RRoller123 has suggested. With the engine running the voltage on the battery should be around 13.8 volts

To measure current leak, Use a multi-meter set on current and put it inline to the battery to measure the current draw, take note what the draw is. Then go to each circuit and do the same thing, it will limit to where to start looking.
There battery tested bad and I replaced it. I have installed a voltmeter and this past weekend the voltmeter read 13-14 volts. I took the gauges out to replace the lights with LED's and when I re-installed the voltmeter it wasn't working, but the car still started. Before I had a chance to figure out the voltmeter, the car would not start even with a jump. I do not have a multi-meter to test the car, so I guess it's time to go buy one. Any suggestions of what I should look for in a multi-meter? Thanks for all the help.
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
User avatar
RRoller123
Patron 2020
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Posts: 8179
Joined: Sun Nov 13, 2011 2:04 pm
Your car is a: 1980 FI SPIDER 2000
Location: SAGAMORE BEACH, MA USA

Re: Power Draw

Post by RRoller123 »

I wonder if one of the disconnected wires in the dash is hot and is running to ground, draining the battery quickly? Check all of the loose ones and tape up any exposed ends with electrical tape until ready to reconnect everything?
'80 FI Spider 2000
'74 and '79 X1/9 (past)
'75 BMW R75/6
2011 Chevy Malibu (daily driver)
2010 Chevy Silverado 2500HD Ext Cab 4WD/STD BED
2002 Edgewater 175CC 80HP 4-Stroke Yamaha
2003 Jaguar XK8
2003 Jaguar XKR
2021 Jayco 22RB
2019 Bianchi Torino Bicycle
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Power Draw

Post by davery »

RRoller123 wrote:I wonder if one of the disconnected wires in the dash is hot and is running to ground, draining the battery quickly? Check all of the loose ones and tape up any exposed ends with electrical tape until ready to reconnect everything?
I taped up the clock connection, but think I forgot the courtesy light connection. The speedo and tach shouldn't be an issue since they have plugs. I will track the courtesy light connection down this morning. One thing I did leave alone was the radio connections. I do not plan on having a radio, but did not want to remove the plugs and such. I suspect the connections are not OEM, as the car had a cheap aftermarket unit when I bought it. I was hoping to just leave these connections under the dash in case I wanted to use later. Thanks!
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
User avatar
divace73
Posts: 1380
Joined: Sun Oct 17, 2010 5:59 am
Your car is a: 1980 Fiat 124 Spider Silver
Location: Sydney, Australia

Re: Power Draw

Post by divace73 »

Multimeters are cheap these days, and will do mostly what you want.
You want one that has DC voltage and Current as a minimum, if you get an automotive type then you may be able to measure RPM as well.

On a side note with the LED replacement, keep the Alternator light as is, most alternators use the resistance of that globe as part of their circuit.
Cheers David
-=1980 silver Fiat 124 Spider=-
If you want to see pics of my car (and other random stuff) >>click here<< OR
see my >>You tube channel<<
davery
Posts: 806
Joined: Sun Apr 15, 2012 8:51 pm
Your car is a: 1985 Spider
Location: Ohio

Re: Power Draw

Post by davery »

divace73 wrote:Multimeters are cheap these days, and will do mostly what you want.
You want one that has DC voltage and Current as a minimum, if you get an automotive type then you may be able to measure RPM as well.

On a side note with the LED replacement, keep the Alternator light as is, most alternators use the resistance of that globe as part of their circuit.
I had read that on this site about the alternator light. I'm actually only replacing the illumination of the gauges. The warning lights and turn signals I'm keeping OEM. At least for now. Thanks for all your help. It's amazing how rebuilding the transmission leads to freshening up the interior. Project creep at it's finest.
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
User avatar
divace73
Posts: 1380
Joined: Sun Oct 17, 2010 5:59 am
Your car is a: 1980 Fiat 124 Spider Silver
Location: Sydney, Australia

Re: Power Draw

Post by divace73 »

good old project creep, all I had to do is repair a broken shock tower (Shock absorber punched a hole) and now my car has been off the road for 2 years.. It was always, while I am there I wanted to get this fixed, then that fixed and so on....
Cheers David
-=1980 silver Fiat 124 Spider=-
If you want to see pics of my car (and other random stuff) >>click here<< OR
see my >>You tube channel<<
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