Oh crap, did I make it worse?

I have an 02 Cavalier with 160k. About 6 months ago, the blower motor went out. I replaced that and the capacitor (the fan had only been working at levels 3 and 4 for a long time).

In the last couple weeks, I noticed my blower fan would periodically not work but then kick on. I know the AC works b/c when I’m on the highway, cool air trickles out of the vent, but no fan to blow it.

I crawled under there and saw I did a poor job of splicing the wires and the connection was corroded. I disconnected it and stripped off clean wiring. When I touched the wires together–nothing. No blower. The wires were hot (because they shocked me). That’s my first problem. Any ideas?

Second problem, the wires coming out of my car (that were at first hot) are now dead. I checked the fuse box and the fuse marked HVAC is good. Any thoughts?

Two things bother me about your post (OK 3) you replaced a capacitor to restore fan speed,you got a shock off your cars 12V DC electrical system and you for some reason had to splice wires? Where was it required to make a splice and why?

I replaced that and the capacitor (the fan had only been working at levels 3 and 4 for a long time).

I don’t see why a capacitor might have been involved here. Usually when a fan only works on the higher speeds is because the lower speed resistors have blown and they usually blow because the fan is wearing out.

After reading your message, I am not sure you have the background for this project.

–Whoops, it was the resistor, not the capacitor. The fan had only been working on levels 3 and 4 for a while before the blower went out but I didn’t replace it until I was already in there to replace the blower.

–I didn’t get a shock but did feel a tingle/burn when holding both wires at first. Now, no tingle.

–The blower was after market, from an auto parts store. The original blower did have plugs connecting the blower to wires from the interior of the car but the replacement part just had wires. This is why I had to splice. I jammed the bare wires from the replacement blower into the plug of the existing outlet and wrapped it with electric tape (I know, not a good idea) and this is where the corrosion was.

Now that we’ve clarified that…

This past Summer, I’d gotten into the habit of turning off my AC just before turning off the car. I take a lot of short City trips and running the AC on high in the Summer heat wasn’t allowing my battery to charge fully. Could it be the fan switch?

Yes it could be the fan switch, or maybe they sold you a bad blower. It is also possible there still is a wiring problem. Sorry I can pin it down any more than that.

But, any idea why the wires are no longer hot? Should I check any fuses beside the one marked HVAC? Remember, the AC compressor still comes on. It is possible the wires touched while I was working on it. Would this have blown something or tripped a breaker?

I’m going to have to get in there and check all my wiring. I wanted to be forearmed before doing that because the blower housing was easy to get out and a PITA to get back in. Is that an automotive version of Murphy’s Law?

I’m trying to understand this post, but a few thing sconcern me.

First, if you got the correct blower it should mate directly to the car’s wiring harness without hardwire splicing. It’s a plug in device, the harness generally plugs into the socket in the motor assembly.

Second, the battery not properly charging. I’d suspect that you’ve possibly created a high resistance short to ground. If it’s creating a circuit parallel to the motor, that’ll split the voltage with your motor, and the motor will still run albiet at a reduced speed. It could be causing enough additional draw on the car’s circuit that the time to recharge the battery is lengthened. Remember that the battery recharges by the alternator pushing additional electrons (current) created by it to the battery, replacing the electrons depleated by the car’s systems. If there’s too much draw due to a high resistance ahort, the alternator may take longer to replenish the battery, making those short trips insufficient.

It’s similar to having a pump-driven stream of water filling little bowls in a yard fountain. Add another bowl and the pump may have diffculty keeping the bowls full, especially if each bowl is continually losing some (akin to components using some of the energy from the flowing electrons to perform tasks).

However, you definitely also want to get your battery and charging system checked. Don’t assume that the new motor is by itself causing the battery charging problem.

Oh and the wires are probably no longer “hot” because the short to ground you created has caused failure elsewhere in the circuit due to excessive current not properly protected by the fuse. That can happen when you create a short. Something has fried.

This is the best theory I can muster for this post. I hope it helps. The best next step is probably to disconnect the new blower motor entirely, replace it with the correct motor, and replace the original harness plug to get rid of the corroded contacts (be sure to connect the wires correctly).

“The battery not properly charging. I’d suspect that you’ve possibly created a high resistance short to ground.” Would that be something along the lines of a wire touching the body of the car? Would it just be somewhere in the area where I worked–It wouldn’t be above the wires leading into the interior, would it? Any idea where to check first to see what I fried?

Electricity flows in this circuit like this: fuse - heater switch - resistor - blower motor. You need to buy a simple test light. Attach the test light clip to ground and start probing. With the ignition switch on and the heater controls on, its time to play “Find the electricity.” First probe the wire you spliced. If you get a light, either the fan motor is bad or the other wire (ground) isn’t making a good connection. If still no light, probe the connections to the resistor. It’s possible that the resistor is bad or you have a bad connection there. Keep working your way back to the fuse. You’ll figure it out eventually.

I wouldn’t buy a replacement motor that required me to cut off a nice factory connector and splice wires. Next time try another parts store. Open the box before you buy it and look it over first.

That would be like a wire touching the chassis through a corroded spot of even through a component that was not in the original circuit. When you’re cutting and splicing wires, you can even creat a high resistance path to ground by miswiring something and directing a circuit elsewhere from the original circuit, even a parallel circuit.

This problem is all too common for people installing new audio system, aftermarket security systems, aftermarket remote-start systems, and such like that. When you start cutting and splicing you really have to know what you’re doing.