81 El Camino with a LS3 and a 3 amp parasitic battery drain.

kreine

Not-quite-so-new-guy
Apr 27, 2021
6
1
Hi all, I'm a disabled vet trying to rectify something that was provided courtesy of two hot rod shops in Loveland CO. I convinced my then wife, now ex-wife to take the car to the Forge in Loveland back in 2014 to get the truck she inherited from her grandfather updated so that it could be a nice daily driver again. Long story short when she got the car back in 2018/2019, the hot rod those guys turned it into has the common parasitic battery drain that a lot of LS swaps tend to get. If she doesn't drive it for 3 or more weeks, the brand new battery is completely drained. I understand that the LS3 has a constant .7 amp draw for memory and what not. When I measure the amperage going to the ECU, I see the .7 amps like I expect. However I've done like 5 minutes of testing and quickly determined that the 18 gauge wire to the battery from the starter and the harness for the cooling fans are pulling a constant 3 amps with the key off and everything shutdown for 30 mins. It might just be me but 3 amps through the starter wire and cooling fan harness when the car should be dormant seems like an odd situation. (I suspect the ignition off the tilt steering column from an 87 Camino that they installed) I need some help trying to isolate the issue so that the car won't be a pain in the *ss to start every time she wants to hop in it and take if for a spin. The shop owner said just put a battery tender on it and refused to diagnose the problem. She just doesn't have the power in the garage to run a battery tender. So the solution he got all crappy about won't even work for her. I figure if I can eliminate the constant voltage to the starter and cooling fans, the battery might quit going dead.

As a bit of a back story, these guys did the following:
1. added a tilt steering column out of an 87 Camino,
2. pulled the dashboard, had it refurbed by that dashboard place in CA
3. Updated the gauges to the dakota gauges using the 87 Camino binnacle for the gauges
4. rewired everything.
5. Installed the LS3 connect and cruise package into the car.

As I said before, I suspect the ignition switch on the column from the 87 Camino but want to make sure I understand the problem completely before I acquire a new switch and install it. I have nephropathy in my hands and legs due to some spinal issues. All that bending and twisting to do the work tends to sap all of my wherewithal and I thought I would ask for help here before I suffered through all that pain only to find out the part I replaced, didn't fix the problem. ;)

Thanks in advance for any assistance,
Keith
 

kreine

Not-quite-so-new-guy
Thread starter
Apr 27, 2021
6
1
Hi all, I'm a disabled vet trying to rectify something that was provided courtesy of two hot rod shops in Loveland CO. I convinced my then wife, now ex-wife to take the car to the Forge in Loveland back in 2014 to get the truck she inherited from her grandfather updated so that it could be a nice daily driver again. Long story short when she got the car back in 2018/2019, the hot rod those guys turned it into has the common parasitic battery drain that a lot of LS swaps tend to get. If she doesn't drive it for 3 or more weeks, the brand new battery is completely drained. I understand that the LS3 has a constant .7 amp draw for memory and what not. When I measure the amperage going to the ECU, I see the .7 amps like I expect. However I've done like 5 minutes of testing and quickly determined that the 18 gauge wire to the battery from the starter and the harness for the cooling fans are pulling a constant 3 amps with the key off and everything shutdown for 30 mins. It might just be me but 3 amps through the starter wire and cooling fan harness when the car should be dormant seems like an odd situation. (I suspect the ignition off the tilt steering column from an 87 Camino that they installed) I need some help trying to isolate the issue so that the car won't be a pain in the *ss to start every time she wants to hop in it and take if for a spin. The shop owner said just put a battery tender on it and refused to diagnose the problem. She just doesn't have the power in the garage to run a battery tender. So the solution he got all crappy about won't even work for her. I figure if I can eliminate the constant voltage to the starter and cooling fans, the battery might quit going dead.

As a bit of a back story, these guys did the following:
1. added a tilt steering column out of an 87 Camino,
2. pulled the dashboard, had it refurbed by that dashboard place in CA
3. Updated the gauges to the dakota gauges using the 87 Camino binnacle for the gauges
4. rewired everything.
5. Installed the LS3 connect and cruise package into the car.

As I said before, I suspect the ignition switch on the column from the 87 Camino but want to make sure I understand the problem completely before I acquire a new switch and install it. I have nephropathy in my hands and legs due to some spinal issues. All that bending and twisting to do the work tends to sap all of my wherewithal and I thought I would ask for help here before I suffered through all that pain only to find out the part I replaced, didn't fix the problem. ;)

Thanks in advance for any assistance,
Keith
I dug into it a bit more yesterday. Looks like the wiring that has the 3 amp draw constantly is the electric cooling fans they installed. Backtracked the wires and the Red/Brn combo that the spliced into the original wiring harness. The red wire is spliced into a violet wire coming off a relay mounted next to the A/C fan motor and the brown wire (I assume the ground)( is spliced into a green wire that comes off the refrigerant sensor. Yes the car still has A/C. I'm assuming that they wired it into the A/C harness because they want the fans to automatically kick on when the A/C system has power. Anyone have any thoughts on how the electric cooling fans should be spliced into a G-Body wiring harness? Remember back in the day everything about the cooling fan was mechanical. The circuits to activate the cooling fans weren't originally in this car.
 

ssn696

Living in the Past
Supporting Member
Jul 19, 2009
4,970
113
Permanent Temporary
Dumb question. No fans are running, right? Any chance the resistor wires in the AC box that drop the voltage for the different fan speeds are staying powered when the car is off? There is a grey multicolored harness that plugs into the top of the AC box. Try disconnecting that and check your current draw again. Armchair diagnosis from afar...
 

kreine

Not-quite-so-new-guy
Thread starter
Apr 27, 2021
6
1
Dumb question. No fans are running, right? Any chance the resistor wires in the AC box that drop the voltage for the different fan speeds are staying powered when the car is off? There is a grey multicolored harness that plugs into the top of the AC box. Try disconnecting that and check your current draw again. Armchair diagnosis from afar...
It sounded plausible so I tried it. Unplugging the resistor wires and the pressure sensor had no effect. However that does bring up another question. The relay mounted right next to the resistor location has an violet, blue, black, red and orange wires. I assume the orange is the ignition wire, the violet wire goes to the A/C fan, and the red wire is what leads to the cooling fans. (I have no idea what the red wire originally powered). Should that red wire have continuous voltage? Is that how GM designed the system? What is interesting is the 18 gauge starter cable is showing 1 amp power consumption constantly and the cooling fans are showing 1.3 amps power consumption constantly. My assumption is that those circuits shouldn't have any power unless the ignition is on. That is why I was thinking it could be the ignition switch.
 
Last edited:

Texas82GP

Just-a-worm
Supporting Member
Apr 3, 2015
6,760
113
Spring, Texas
A bad diode trio will cause a steady drain. Flemming442 just reminded me of that.
 
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kreine

Not-quite-so-new-guy
Thread starter
Apr 27, 2021
6
1
A bad diode trio will cause a steady drain. Flemming442 just reminded me of that.
So the test procedure I used was to disconnect the battery, disconnect the red and green leads from the wiring harness on the alternator, reconnect the battery and read the voltage. With the alternator disconnected, the amps being drawn increased from 2.3 to around 2.8. So I don't think that is the root cause of my battery drain.

I found a link to the wiring diagrams, http://www.maliburacing.com/wiring.html, that shows the "charging circuit" and the "four season air conditioning" wiring diagram. On the bottom left of the "four season air conditioning" diagram you can see the red wire coming in from Fusible Link A. I'm attaching a couple of photos to show what I describe next. Essentially what they have done is run a hot wire from the positive terminal of the battery to a terminal on the side of the LS3 fuse box. Then the top left terminal has two red wires coming out. One goes to the High speed blower motor relay and the other goes to a relay for the electric cooling fans mounted right above the battery on the fender.

Should those cooling fans be switched? Is that what the relays are supposed to do? Could I have a bad relay or could the relay block have bad wiring that creates a short? I'm just not smart enough about how the Griffin Thermal Solutions cooling fans are supposed to be wired. Anyone got any ideas.
 

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Last edited:

fleming442

Captain Tenneal
Supporting Member
Dec 26, 2013
13,032
113
No, that doesn't sound right. The fusible links are 12v feeds to the ignition switch, alternator charge, and high speed blower relay. They can be anywhere as long as they are battery power. My suggestion would be to pull the dome light fuse, put a test light in series with one of the battery cables. The draw will make the test light illuminate. Then start pulling fuses until the light goes out. At least then you'll know which circuit has the draw.
Relays are basically switches. Unless it's hung up, it shouldn't have any static draw.
 
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64nailhead

Goat Herder
Supporting Member
Dec 1, 2014
2,909
113
Upstate NY
No, that doesn't sound right. The fusible links are 12v feeds to the ignition switch, alternator charge, and high speed blower relay. They can be anywhere as long as they are battery power. My suggestion would be to pull the dome light fuse, put a test light in series with one of the battery cables. The draw will make the test light illuminate. Then start pulling fuses until the light goes out. At least then you'll know which circuit has the draw.
Relays are basically switches. Unless it's hung up, it shouldn't have any static draw.
10-4 ^^^^ on this. You can use a multimeter rather than a test light also, but both will work.

I'll add that in my world a 700 milliamp draw is way too much. It will drain 3 1000cca batteries in less than 2 weeks with that much draw. And in a month ruin the batteries.
 
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kreine

Not-quite-so-new-guy
Thread starter
Apr 27, 2021
6
1
No, that doesn't sound right. The fusible links are 12v feeds to the ignition switch, alternator charge, and high speed blower relay. They can be anywhere as long as they are battery power. My suggestion would be to pull the dome light fuse, put a test light in series with one of the battery cables. The draw will make the test light illuminate. Then start pulling fuses until the light goes out. At least then you'll know which circuit has the draw.
Relays are basically switches. Unless it's hung up, it shouldn't have any static draw.
Noticed a ground wire going from the relay for the cooling fans to the fender. Pulled the grounding wire and there was lots of paint underneath the loop. So I used an Emory board to get the surface under the connector down to metal and now my meter is showing .5 amps instead of 2.3 like before. Not entirely convinced that was the problem but numbers and test tools don't lie. Now I'm off to pull the radiator so I can see if a pin hole that magically appeared after the last service when they installed a power steering reservoir to keep that from dripping on the ground. Thanks for the input guys. I think this will dramatically slow the rate of discharge on the battery. ;)
 

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