Need help, got a draw on my battery. Put a test light between the negative post and the cable and it lights up, pulled one fuse at a time until all were removed and the light never went out. Don`t know where else to look for the draw. Battery loses about .3 of a volt a day. Thanks for any help.

 

Unplug the connector on the alternator. A leaky diode will cause a constant current drain from the battery.

 

x2

 

I should have said this in my write up. The alternator has been replaced to a one wire and the voltage regulator has been removed. Same problem.

 

Just curious if you happen to know the model & year of the car?

 

Sorry for that. 1971 Cutlass, was a 350 but someone put a 455 in it before I got it. Thanks

 

You mean the external VR has been removed since you went with a single wire generator - obviously the VR is built into the single wire generator. Did you do the generator change or someone else? I'm curious if the wiring was done correctly.

 

The one wire alternator only uses the main red wire and the 2 prong alt plug just stays unplugged, same as the VR just is unplugged also. The battery is getting charged just fine, but the problem has been there all the time. Also new battery. The only thing that runs is the clock that I know of.

 

Do you have newer style audio equipment installed?

 

Is it an original clock? I have read that as they age worn an sticky parts can cause a higher that typical current draw.

 

Thanks I will look into the stereo when I get home sunday, will unhook it and the clock.

 

If you pulled the fuse for the cigarette lighter and dome light, and the draw is still there, it’s not the clock. I don’t have my manual handy to check but the clock is on one of those fuses

 

The clock, cigar lighter, dome lamp & courtesy are all located on the same 25A fuse for a '71 Cutlass.

 

You should have several circuits powered off the horn relay that do not go through any fuses in the fuse box. If pulling all of the fuses doesn’t isolate the draw my next step would be to remove the wires from the horn relay lug one at a time until you find the draw.

 

The diodes inside your one-wire alternator can leak too so you might try disconnecting that as well. Aftermarket audio equipment is often blamed for current draw whole the vehicle is turned off but it is easy to test. If your head unit is digital, it will have one ACC (switched) lead and one back-up (constant power) lead. If it is working correctly it will only draw a few mili-amps Pull all the fuses and see if you still have the draw, same as you did with the vehicle fuses. If you have an amplifier (or more than one) the same applies, pull the fuses. Another thing to look at is your horn relay. On my 67, the horn was burned out (I didn't know that) because a previous owner installed a Grants wheel and the notoriously bad horn button was always shorted. The horn relay still worked but not the horn so it was always drawing power. It is easy to unplug.
Just a few thoughts.

 

First want to thank you all for stuff to check out. Did the test light again while I unplugged wires off the horn relay, the green light got real dim. By the way the horn doesn`t work. Will check the battery tomorrow and see if the volts go down. Will look at the horn later. Busy week this week, not much time to play on the car. Thanks again. Love this web sight.

 

The green wire on the horn relay is the power feed for the horns. If you disconnect that, and your draw disappears, that suggests the horn relay is either being triggered (the black wire goes to the horn button in the steering wheel) or the relay itself is stuck. Since the horns don’t work, it’s entirely possibly the horns themselves are stuck, drawing current even while not making noise.

Get a test light, connect the alligator clip to the positive post of the battery. Put the probe on the black wire of the horn relay. Every time you push the horn button, the light should light up.

Jumper the green wire to the stud on the horn relay, the horns should sound. If not, take a hammer handle or some other “tool of persuasion” and smack the horns a couple times. Sometimes the horns need a little attitude adjustment to get them going again. If they don’t sound, or at least click or make noise, they are probably severely corroded internally.

Since I’m cheap, I used horns from a Cadillac Fleetwood on my Olds. I transferred the mounting tabs from the original Olds horns onto the Cadillac horns. This gave me environmentally sealed electrical plugs, horns with some authority, and cost basically nothing but some time to fabricate the mounting and wiring.

 

I will look into all that next week. Thanks Matt

 

Ok, On the draw test I pulled the clock, lighter, and courtesy light fuse and the test light went out. Just got to narrow that one out

 

Sounds like your getting closer. Be careful with the cig lighter as they have been known to stick and cause issues, melting dashes and or fires.

 

Easiest thing is pull the bulbs on glovebox and trunk lamps if car has them. If draw goes away, sweet and simple.

Does the clock work? It shouldn't pull down the battery that hard or fast, but if its points are burned together it could do it. I'd think that would blow a fuse though.

Past that, wiring diagram and patience. Shoot some WD40 or contact cleaner in the door jamb switches and see if that helps.

 

Trunk lamp, console lamp, glove box lamp, clock power feed, things like that are all powered by that fuse. Don’t forget anything aftermarket that might have been added over the years.

This is where a factory wiring diagram is helpful. It shows all the factory connectors. For example, if you unplug the taillight harness connector and your draw goes away, then that leave the main dome lamp, and trunk lamp. The console and other courtesy lamps have a connector that plugs into the fuse box, and would still be powered with the taillight harness unplugged.

Electrical issues are some of the most irritating and satisfying problems on a car. Trying to solve them are infuriating, and the “Ah-Ha” moment is refreshing.

 

Narrowed it down to the courtesy lights. Removed the 5 bulbs, ( 3 dome and 2 under dash ) and the test light went out. May live with that until I rewire the whole car. Thanks for the help.

 

Did you hold the door switch closed when Testing?

 

No. Was I suppose to?

 

Light stays out with doors open or closed.

 

Is that the test light staying out with the 5 bulbs pulled? Put the lights back in and see if any of them are on in the dark.

 

Yes on your first question. Put bulbs back in, closed doors and all bulbs went out.

 

Was the current draw still there w bulbs in and not lit? Inquiring minds wanna know!

 

Yes

 

Make sure you have the correct bulbs in the underdash and sail panel lights. I think they should all be single filament double contact bulbs but look in the sockets themselves to see whether it should have a single or double contact. Owner's and service manuals will have the correct bulb number.

 

Will do. Thanks