Accumulating electrical issues

I'll start off by saying my truck has never been babied. Purchased with a rebuilt title, I've now doubled the mileage at 142k since then. Operating a landscaping business trying to find common ground between a work truck and a daily driver, my Tacoma hasn't let me down.. especially after taking into consideration hauling the occasional fully loaded trailer all day and snow plowing every season.

Eventually the alternator gave out as expected, besides the fact I was on the highway mid-summer. Soon after the red warning light on the dash lit up, every electrical system slowly began to fail. Started with erratic: idling/shifting and speedometer readings. Then: A/C, stereo, PW, and complete dash systems failure. Finally: loss of engine power until I was roadside. A fresh battery was delivered on site to drive it to my shop and avoid towing fees.

Recently, I've been noticing a rise in electrical malfunctions.
First off, I've been searching for a high-output alternator before the original gave out. But even with a fresh OEM replacement, the truck come close to stalling out. The blower slows down and all the lights dim inside and out every time I lift the plow. Obviously the new alternator doesn't provide sufficient power.

With NO plow mounted:
All of the steering wheel mounted controls have not been functioning properly. Including the horn, stereo volume buttons, and cruise control ( occaisonally doesn't turn on ).
And now my blower system only works on the high setting. These issues started before the alternator replacement but have progressively gotten worse since.
What could the issue be? Have I possibly damaged my trucks electrical systems?

 

The blower settings other than high are controlled by a resistor, problems are common, you can find threads about it on here. It's by the passenger's left foot, easy to get to.
I fixed mine by prying the contacts out with a small screwdriver and applying dilectric silicone grease as the contacts kept getting burned. There are replacements but mine is working fine now.
I don't know about the other problems.

 

That makes sense, I'll be sure to try that. Thanks

 

Those SW issues could be from a bad ribbon cable. There have been reports of recalls on that part. Your rebuilt title might have been the reason you never received a notice. With that said, the ribbon cable is a fairly cheap part and can be replaced easily.

 

Are you handy with the Toyota repair manual ?
Sounds like you have multiple issues .
http://www.customtacos.com/tech.old/files/05FSM/repair.html

 

Lots of great info here. Thanks! I'm no expert but ever since I started adding electronics, (not just electrical) stuff, an old mobile phone installer strongly suggested that whenever I weld on the vehicle, to disconnect the alternator. I've always done this & most of my electronic problems are self inflicted.

 

Is the ribbon cable located under the driverside dash next to the steering column?

 

No, under the steering wheel air bag.

 

Yeah, that actually makes more sense. I'm sort of hesitant to start poking around in that area.. anything I need to know in order to avoid deploying the airbag in my face?

 

Disconnect the battery and turn on the lights to dissipate an any surface voltage.

 

Ok great. I'll give it a shot, thank you!