Most Common Electrical Short

[turbohye]

Ok,
Spent the whole weekend lookind for this short.
Hooked up the test light today and pulled every fuse one by one. and the light never went out on the test bulb. I did make sure i closed the door every time i pulled a fuse just to make sure that the light wasnt coming from the door being open. I even unplugged the Fan Delary Relay and it made no change. I pulled and tugged and disconnected every connector in the engine bay but that light was still on (Very Dim) but still very noticeable. At this point guys/gals i have no idea of what i should do. I checked and rechecked but still cant find out where the drain was coming from. Any other ideas guys?
thanks in advance for all those great suggestions.
-Tony

 

[turbohye]

BTW i definately disconnected the trunk bulb and hood bulb. no change.

 

[GNVYUS 1]

I think what GN Venom is getting at is the fan will turn on while the car is parked and left to sit. That will drain your bat every time if the fans are running for hours and then stop.

 

[turbohye]

i hear what you are sayin' but with it plugged in or not, i still have a parasitic drain. I will unplug it and leave it unplugged for the time being just to make sure. But wow that relay does sound like a bad thing.

 

[49-blues]

Does your voltage light in the dash come on when key is in on position- if not i heard the light bulb being out will drain your battery in no time. I think its attached to a brown wire.

 

[87Jen]

I think what GN Venom is getting at is the fan will turn on while the car is parked and left to sit. That will drain your bat every time if the fans are running for hours and then stop.

I pulled the fan delay relay, popped the plastic top off and it looks really nasty. I hope this is the culprit. See what you think:

 

[NASSTY]

I pulled the fan delay relay, popped the plastic top off and it looks really nasty. I hope this is the culprit. See what you think:

It looks like the culprit.

 

[TurboBuRick]

I think what GN Venom is getting at is the fan will turn on while the car is parked and left to sit. That will drain your bat every time if the fans are running for hours and then stop.

That is a common problem although I think he is saying that power will actually leak through the rust causing a slight short.

i hear what you are sayin' but with it plugged in or not, i still have a parasitic drain. I will unplug it and leave it unplugged for the time being just to make sure. But wow that relay does sound like a bad thing.

Did you disconnect the ecm wire at the bat.?

I pulled the fan delay relay, popped the plastic top off and it looks really nasty. I hope this is the culprit. See what you think:

That looks like it could definitely be a problem.

 

[turbohye]

Ok guys/gals. I left the car the car off the charger last night to see if i would have any juice in the morning and since last night i had disconnected the Fan Delay Relay. Sure was dead. Last night i swapped in a new battery BTW and that didnt help. I did pull every fuse and relay in the fuse panel including the FDR in the engine bay, so i am assuming this is going to be one of those unlucky times where i have to find this sucker. Unfortunately, i have no other vehicles to drive at this time so i will have to jump the buick with my jumpbox. To give you a rough idea, the drain is very miniscule. I can drive the car around and lpark it, walk away for 5-7 hours and come back and it starts (kinda slow) but it starts. But when its left out longer especiallyin the cold overnight, it has nothing in the battery by morning time. I am going to pull the CD player out when i have a minute and see if there are any open wires. The CD player is aftermarket and i remember checking it last year, but it wasnt the issue. Any guys up here in MD willing to help out? Denny's on me.:redface:

 

[nolitlwhls]

I asked earlier about the condition of the alternator you said it wasnt the problem in an earlier post is it new? If it is not new you can disconnect all the wires to it and let it set, sometimes you can see a spark when you hook up the positive wire which doesnt mean it is a draw and on the other hand it can be, if isnt new I would try this just cause it is charging doesnt mean it wont draw on the battery when its not running, if it has been tested I would still try it, I have seen them still draw depending on the type of tester that was used, another spot to check would be the fuel pump relay or switch I am not positive on the buick whether there is an oil pressure switch that turns on the fuel pump or not generally if it has an electric pump there will also be a switch, if switch is bad it can hold the fuel pump relay on, Just a thought

 

[turbohye]

Thanks man, i tried it just an hour ago and the alternator definately isnt the culprit. Actually, this is the second alternator since i owned the car. The first was replaced because of a manufacturers fault. Car idles like a cadillac but sure wish it started like one.

 

[ngnowner]

electrical problems are a pain

See if this makes sense, you've pulled all the fuses & bulbs, but the test light stays on. I'm far from an expert but I think you've narrowed it down, it must be in front of the firewall. I can't think of anything that's not covered by a fuse from the firewall back. Did you diconnect all the relays under the hood with the test light connected? Next I would think non-fused engine electrical, starter, solenoid-wiring, alternator, battery cables. I would try disconnecting those with the test light hooked up. Draining a new battery down in 10-12 hours is a fairly substantial drain if you think about how many amp hours are in your battery. If you have a digital voltmeter that also has an amp tester (usually light amps only, 10 or less and only will read for a few seconds before circuit breaker heats up), try putting that across the neg cable and terminal to see how many amps it's drawing. If the amps are significant >5, it's probably a large short in a heavy wire, 10-12ga or higher. Smaller wires would have burned up by now. Try the trans connector(s)too. I had the sam problem on an RV once turned out tha the insulation was burned off the starter solenoid wiring and it was just touching the heat shield a little.

 

[turbojd]

I would check your radio wires again like you said, do you run an amp? maybe relay went bad amp staying on? Maybe the factory alarm. Maybe a bad diode in the alternator.

 

[turbohye]

thanks for the tip. I will go buy a tester and see. A buddy of mine is stopping by with a commercial short locator. Apparently there is a buzzer that has an audible sound within 3 feet of the open circuit. The closer you get to it, the crazier the noise gets. It apparently is old technology but he said it generally helps with all the cars in his shop that come in. Most of the older cars that he works on are GM and Ford and whenever people report issues with shorts, he says this tool saves about 80% of his time. I honestly never checked that wire under the shifter that everyone reports having an issue with. Like you said though, maybe its not a short behind the firewall, it does seem its in the engine bay. I will let you guys know this week what him and I find, or if we find anything at all. Hopefully its so simple, i will just smack my forehead and walk away.
thanks for the help and great suggestions.

 

[87Jen]

fan delay relay

The fan delay relay is probably your culprit. What happens is this: The relay is not sealed, so it picks up moisture, which eventually rusts the internals. The rust works its way between the hot side of the relay connection and a ground, causing a trickle of power to ground.

I've even seen a condition where the car starts but won't shut off due to an internal short of this relay. I've seen this happen at least three times over the years to different GN owners.

Fix: Unplug the relay connectors and forget about the problem. You really don't need that relay anyway, as it's a source of potential problems. Take it out of the equation.

The fan delay relay was the answer to my problem. I disconnected it and let the car sit for 5 days. Normally it would've been dead in 2 days, tops. But, it cranked right up, no problem. When I told my local mechanic that I had found the problem myself (no thanks to him I might add), he was like "No way, you've got to be kidding me! How did you figure that out?"

You guys are the best, thanks for the info!:biggrin:

 

[Sleeper-6]

You may want to pick up one of those cheap battery disconnect switches and use it untill you have this problem figured out. It will stop the drain from destroying your battery. (they don't like being drawn down that far, it will definately shorten the service life of the battery, and maybe the altenator because it has to work harder to charge the battery after every jump start) It will also keep you from being stranded somewhere. Where there is a short there is heat, where there is heat there is potential for fire, so I would recommend disconnecting the battery when you are not around.

 

[Lhorn]

Just disconnect your battery when you park it overnight. There's no reason why this problem should necessarily leave you stranded. I've had a problem like this for a year or so.

The fan delay relay has me interested. What happens with the relay? Does it actually make the fan go on later after you've left the car or does it just short out and suck your battery without running the fan? If you connect a test light between the battery and the neg. cable, then pull the relay, the light should go off if it's the problem?

Thanks.

 

[GNVenom]

The fan delay relay has me interested. What happens with the relay? Does it actually make the fan go on later after you've left the car or does it just short out and suck your battery without running the fan?

Both scenarios can happen. It can fail and cause the fan to run on high at any given time. This happens particularly if your battery voltage drops below 10 volts where the circuit "freaks out" and turns on on its own. This can actually happen with a perfectly good delay relay.

It can and often does fail due to excessive moisture entering the housing, causing the rust as you can see in a previous post. The rust is conductive. And, since the relay is connected to both switched 12 volts and live 12 volts, along with a ground, a short circuit potential exists by nature. Not a very good thing to have under your hood huh? Talk about blind faith...

I have been preaching for years to remove the delay relay altogether. Two connectors and your potential problem is solved. I realize the engineers designed that part for what must have been a very good reason, but remember, most, if not all, GN's by now have had their 190 degree thermostat replaced with a 160 'stat, so the build-up of heat is no longer a concern. There is really no need for the delay relay.

 

[Mark E.]

Years ago I replaced the delay relay sensor with one of these.

Hypertech 4026 - Hypertech Cool Fan Switches - summitracing.com

That one shows a different connector, but when I bought it the connector was exactly the same.

Also replaced the delay relay.

The fan probably runs more than it has to, but it runs cool. When you park it hot, the fan runs to cool it down. I always figured when I got back in, there was some nice cool water in the radiator to cool the motor.

Probably not required, but it seems to work pretty well.

The stock sensor does not come on until around 240 degrees IIRC.

Mark

 

[Lhorn]

I have been preaching for years to remove the delay relay altogether. Two connectors and your potential problem is solved.

What 2 connectors are you speaking of?