my battery is draining

[ocbaud]

crap **** ****!


alright, i've had this issue for a long time now.

when ever my fan selector switch is on any other position besides off(as in a/c, vent, heat, defrost) it will draw power from the battery even when the ignition is off.

i've replaced the switch panel and just now replaced the blower motor resister and it still has the same problem.

i have my multimeter hooked up to the battery. it got real low becasue of this, so right now its reading 9v with the switch off. if i turn the switch to a position like vent, it will drop down to 8.6v and keep droping .01 every couple seconds.

if i unplug the connector from the blower motor resistor, the battery goes back up to 9v like it should be(for a low battery that is)

any ideas? the grounds all look good and so does the wiring

[DROPPED15]

I Had A Problem With Battery Draining In About 2 Days.i Check Every Possible Electronic Part On My Truck It Turned Out To Be The Ecm.(87 Chevy Efi) The Fan Relay Switch Mounted On The Ac Box Next To The Blower Motor Could Possibly Be The Problem!i Think It Has Voltage Going To It Al The Time.

[ocbaud]

no

this is what all i've replaced:
the switch panel
blower motor resistor
fan relay
blower motor

and its STILL doing the same damn thing!

i dunno what else there is. but the problem is for sure with the ac/heater system because when i pull the fuse for it, the problem goes away.

[DROPPED15]

UHMM!

[ocbaud]

i've also cleaned up all the ground connectors that are over there by the blower motor. that didnt help at all

[ElGracho]

Where is your blower switch getting power? It sounds like it is wired to the battery but it should be to an ignition switched source. I thought that connection was internal to the fuse box. Get an original wiring diagram and chase down that wire. Seems like you have it figured out, you just need to find exactly why that is getting power and fix it back to the way its supposed to be.

Did you tie into that wire with your stereo or alarm and back feed it? Something like that?

[ocbaud]

i've got the wiring diagram(even though it sucks) and it isnt helping all that much

i really dont know what else to look for.

i've disconnected the wiring for my electric fans, the msd box, and the alarm and they have no affect on it at all. so its just the hvac system by itself.

since i've had my interior gutted for the last month, and i've been redoing the wiring for the alarm and stereo, i know for a fact that nothing is tied into the wiring for the hvac controls. all of the wiring looks good.

[krue]

Hook a test light between the negative post and the ground cable on your truck and start pulling fuses until the light goes out.

[ElGracho]

The fuse that should make the light go out is the heater fuse. For some reason, the power side of that fuse isn't switched with the ignition switch like it should be.

[ocbaud]

Originally Posted by krue

Hook a test light between the negative post and the ground cable on your truck and start pulling fuses until the light goes out.

tried that with a multimeter

i pull the heat/ac fuse and it stops drawing power

[ocbaud]

Originally Posted by ElGracho

The fuse that should make the light go out is the heater fuse. For some reason, the power side of that fuse isn't switched with the ignition switch like it should be.

with the ignition off, the fan quits blowing so its switched somewhere along the line

[ElGracho]

Use your voltmeter and get it where it's drawing. Then put the fan switch on high and see if it goes away.

[ocbaud]

Originally Posted by ElGracho

Use your voltmeter and get it where it's drawing. Then put the fan switch on high and see if it goes away.

done that already,
it does not go away.

the fan switch actually doesnt have any effect on it.
its the selector switch that is whats causing the problem and causing the power draw

[krue]

You checked that circuit to see if it is grounded any at all?

[ocbaud]

Originally Posted by krue

You checked that circuit to see if it is grounded any at all?

yes, if i remove the ground it stops drawing power

[boxrodz]

If I follow you, you say your hvac system is drawing current with the ignition off and with the selector switch in any position other than off. But, you also say that the blower motor shuts off once the ignition is off. Is that correct? If so, then we're assuming that the blower motor is not causing the drain?.

Power to the HVAC is supplied by ignition power as El Gracho mentioned. So, the selector switch should not be drawing any current once you shut off the ignition. BTW, does the turn signals or wipers work with the ignition in the off postition?

[ocbaud]

Originally Posted by boxrodz

If I follow you, you say your hvac system is drawing current with the ignition off and with the selector switch in any position other than off. But, you also say that the blower motor shuts off once the ignition is off. Is that correct? If so, then we're assuming that the blower motor is not causing the drain?.

Power to the HVAC is supplied by ignition power as El Gracho mentioned. So, the selector switch should not be drawing any current once you shut off the ignition. BTW, does the turn signals or wipers work with the ignition in the off postition?

if it is drawing power and the switch is in an ON position, it will quit drawing power if i do any of the following:

pull the heat/ac fuse
disconnect the powerwire to the blower motor
disconnect the blower relay
disconnect the blower motor resistor
disconnect the selector connector from the selector panel
disconnect the wire coming from the fuse box into the panel harness

i dont believe the wipers or signals work with the ignition off, but i'm not 100% positive, i'll check that when i get home. i know they shouldnt be

[ElGracho]

Originally Posted by ocbaud

...
disconnect the wire coming from the fuse box into the panel harness...

What is this wire? What color is it? Where does it plug in? What does the plug look like?

[ocbaud]

Originally Posted by ElGracho

What is this wire? What color is it? Where does it plug in? What does the plug look like?

it runs from the wiring from the control panel, to the big bundle of stock wires down to the fuse box. its completely stock, but i'll get a picture in a bit

[ocbaud]

this is the connector that goes from the hvac controls to the fuse box


the wiring for the hvac controls exit the firewall through here


some of the wiring goes over here


and 1 wire goes here(on the left)

[ElGracho]

If I'm seeing correctly in the first picture, that connector is brown and plugs into the front of the fuse box. Is that right?

Now get a picture of where you are plugging it in. Take a pic and circle the outlet or something. I'm convinced this is the problem.

Another thing to check is to make the drain however you need, then unplug that wire from the fuse box and see if it has voltage to ground without changing anything else.

[ocbaud]

Originally Posted by ElGracho

If I'm seeing correctly in the first picture, that connector is brown and plugs into the front of the fuse box. Is that right?

Now get a picture of where you are plugging it in. Take a pic and circle the outlet or something. I'm convinced this is the problem.

Another thing to check is to make the drain however you need, then unplug that wire from the fuse box and see if it has voltage to ground without changing anything else.

the connector runs to the BACK of the fuse box. it does not plug into the front at all.

[ocbaud]

found the problem i think




the other bare wire was connected to the 2 read wires which ran directly to the fusable link.

the bare wire needs to be connected to the ignition switched.

yes, my bad when i rewired that crap with the new engine....

so where exactly does this wire need to run to right now? i hooked up a temp wire from it to the ignition fuse in the fuse box and all works perfect, but i want to wire it into the correct area

[ocbaud]

so....

would this wire normally be ran to the switched wire on what????

[boxrodz]

If I'm following, then it is the blower motor causing the power drain. Can you hear the blower motor when the ignition is off?

In the first picture, the brown wire running from the HVAC selector switch to the connector then to the back of the fuse box looks correct. This should be the fused feed from the switched (ignition) power.

The one wire (red) coming from the left terminal of the junction block (in the fourth picture) should be the battery power feed going to the blower relay. The orange wire at the blower relay should be one of the wires coming through the firewall from the blower switch. When the blower switch is set to High, the orange wire triggers the relay to send the battery power feed from the junction block to the blower motor. The black wire from the blower relay, is ground. The purple wire coming from the blower relay should be going to the blower motor and is the power source. The dark blue wire coming from the blower relay should be coming from the blower resistor. It is the source of variable power for the blower motor (thru the blower relay) depending on the HVAC selector switch setting.

I think the light green wire is used for the A/C setting. The light green wire comes through the firewall from the HVAC selector switch. In the engine bay, it is spliced into a connector with another light green wire coming from A/C evaporator pressure control switch. The other side of the connector is a light green wire going to the fast idle soleniod. But, I'm not sure why this wire would affect the power drain coming from the blower motor. If this was the wire was connected to a battery source, maybe you were introducing power back into the HVAC panel.? Do you get any drain if you leave this wire disconnected?

I would check the dark blue wire to see if you sense any voltage drop between the wire and ground when the ignition is shut off. You shouldn't have any voltage drop across it with the ignition off.

I believe that's the operation...

YM(or colors)MV...