Need help troublshooting strange electrical issue in '04 DC TRD OR

My baby has been acting strange for a while now. Still totally driveable, but I think I need to address them. The issue(s) appear electrical in nature, and seem to involve the right turn signal, headlights, cruise control, and brake pedal.

1. Left turn signal activated results in fast left blinker. (I suspect a burnt out bulb)
2. Right turn signal results in "normal" blinker.
3. But if I step on the brake pedal while the right turn signal is activated, the blinker seems erratic, and somewhere between the slower, normal blinker speed, and the fast blinker speed indicative of a burnt out turn signal bulb.
4. [ Noticeable @ night or in low light: ] Step on the brake pedal and the right turn signal (i.e. the right arrow light) on the instrument cluster glows a solid green light, but NOT as bright as when the right turn signal is activated. Let off the brake and the right arrow light goes out. Somehow the brake pedal (circuit ?) is interacting with the right turn signal (see #3 as well)
5. [ Noticeable @ night, but I think it is when the headlights are on ]: on the highway, when accelerating and the right turn signal is activated, a weird "UHHHuuuhhhhUUUHHHuuuhhhUUUHHHuuuhhhUUUHHHuuuhhh..." surging sound seems to emenate somewhere behind the driver, on the left side of the vehicle. It is a surging, sinusoidal kind of sound. It is most noticeable on the highway, say at 60+mph, and especially when asking for power (e.g. acceleration) from the motor. Turn the right turn signal off, and the "surging" noise stops. Does not happen with the left turn signal activated. I do not recall this occurring during the day. Only at night. I think the common denominator is that it only occurs when the headlights are on. I do not recall the motor itself surging. I don't recall buffeting or acceleration / deceleration of the vehicle or motor. Just the "surging" noise. If I didn't know any better, I'd guess that the fuel pump sender unit in the gas tank was "surging" -- almost like some kind of electrical issue of some kind was causing the fuel pump to surge.
   
6. If cruise control is turned on and a speed control set, activating the right turn signal results in the cruise control speed hold function deactivating. The dash light indicating that cruise control has been turned on remains lit, but if I had commanded it to hold a speed, that is turned off when the right turn signal was activated, and the vehicle will lose speed. This does NOT occur if the left turn signal is activated.

Has anyone experienced these problems before?

How to trouble shoot it?

If I had to guess, I would suspect that some relay, or switch, or multifunction module, or electrical doodad in the steering column, connected to the turn signal stalk, has suffered some sort of short or failure. My hope is that simply replacing that "doodad" would fix the problem.

My fear is that the electrical gremlins may be numerous, and tracing them all down could prove time consuming and expensive.

Thanks for any help, tips, insights, words of wisdom or experience etc.

 

Sounds to me like your system Voltage is really low with the electrical load.

causing the gremlins to breed and cause havoc.

time to break out the meter get some real world voltage readings or get some help close to you

A short would cause circuit protection to open a open circuit would cause the circuit to not work.

Electrical problems are best with hands and eyes on the problem

Any Chance Evil Rodents could have been chewing on your wiring ??

 

1, 2, 3 and 4 sound like bad rear bulbs. Which ones? Just change all of them. There is a reason they come in pairs.
5 and 6 sound like you have a bad ground possibly. Check the body ground right at the NEG terminal of the battery. I've seen that break and cause weird issues.

 

replace burnt out bulbs, check battery voltage and alternator output, replace flasher relay

 

Could this be anywhere? <groan> Or is it most likely to be at or near the battery?

 

Where is the flasher relay located? Under dashboard? In engine compartment? In steering column? (Sorry if this is a stupid question.)

 

Sorry if this is a stupid question: how does one troubleshoot looking for bad grounds? Visual inspection of chafed wires? Visual inspection / identification of copper wiring touching bare metal somewhere? Or are there specific ways to use a multimeter? (E.g. probe on one end of wire, probe on what should be opposite end of wire and listen for connectivity? OR check resistance? If the wire is grounded... I guess what would mean connectivity is shot, so resistance would be high or infinite?) I'm a n(.)(.)b when it comes to troubleshooting most auto problems, especially electrical...

 

Not positive on the 1st gen, but most likely under the drivers side dash column or behind the radio. Easy way to find it, turn the signal on and listen for where the relay is clicking