The fuse for my blinkers keep going out.

hey guys so i have a 2001 Toyota Tacoma and my blinkers went out the other day so i checked the fuse and sure enough it had popped so i put a new fuse in and as soon as i hit the blinkers it pops i can not figure out where it is shorting out at. any ideas would be greatly appreciated.

 

Well it might be a bulb is shorted ..

Look at the bulbs

It might be Physical damage to the wires .

Drill any holes for anything ??

Did the harness get against the exhaust

Look around the turn signal lights for damage

 

i will definitely check out the bulbs what would a shorted out bulb look like?

 

Most likely the filament will be broke and touching the metal of the bulb

Or just black and burnt or even broken.

 

ok ill check that first then im probably gonna have to start chasing wires around if that's not the problem

 

https://www.motor.com/magazine-summary/bright-idea-for-short-detection/

'Bright Idea' For Short Detection
By Thomas R. Tillman

Sometimes you get lucky, and the location of a circuit that’s shorted to ground is easy to find. But the rest of the time, a systematic approach must be used to make short work of the problem.

BrightCover2

How many times have you had customers bring their vehicles in for electrical problems? I’m sure this happens quite frequently. Of course, when an electrical problem rolls into the shop, one of the first things we do is check the fuses. Once we find a blown fuse, we replace it with a new one.

However, what do you do when the new fuse blows as soon as the circuit is powered on? This type of short-to-ground problem should be easier to troubleshoot than an intermittent short, but can still be troublesome.

Diagnosing any short-to-ground can be not only time-consuming but costly as well. Just the estimated cost of the diagnostics/repair will sometimes chase the job right out the door.

It really doesn’t have to go that way if you’ve done your homework. Realistically, you should be able to locate and isolate a dead short in two hours or less.

As with any electrical problem, start with a wiring schematic. The more you know about the circuit operation and wire routing, the more likely you’ll be able to locate the problem in an even shorter amount of time.

The challenge of trying to locate and fix the problem comes next. Each of us no doubt has tried different approaches to locate a short-to-ground. My approach is different and seems confusing to some of the technicians I work with. However, they’re amazed at how quickly I seem to be able to solve electrical problems.

We recently had a vehicle in our shop that had returned for the third time. The customer could leave the vehicle only for a few hours each time. It was my turn to try to locate and fix the problem. The vehicle had a short-to-ground in the taillight circuit. As soon as the taillights were turned on, the fuse would blow.

Electrical Pulse Signal Tool

I plugged my electrical pulse signal tool (a 4A headlight wired in series with a turn signal flasher) into the taillight fuse connection at the fuse box. The idea was that with the short-to-ground present in the circuit, the flasher would trigger the headlight on and off. This would create a low-voltage pulse in the shorted circuit. Even though the voltage signal pulse is small, it’s still measurable.

This is where a lab scope becomes very useful. The scope has the capability of clearly displaying the voltage pulse. This pulse also has a unique signature pattern. Therefore, the pattern cannot be confused with other on-board signals.

I’d like to point out that a DVOM with a Min/Max range could also be used, if you don’t own a scope. The only reading you’d need to focus on is the maximum voltage recorded. However, you’d need to reset the recorded reading for each test; on the other hand, the scope display can refresh each time the scope is connected to the circuit.

I connected the scope negative lead to a good chassis ground, and the positive test lead to the flasher and light at the fuse box. I made sure to connect the test lead to the circuit side of the tool. This gave me a starting reference voltage signal. The voltage pulse recorded on this vehicle was 2.4V max.

Next, I started to test the taillight circuit at the rear of the vehicle. The voltage pulse was 1.66V at the taillight socket. As I moved up the wiring toward the dash by probing the connectors or wiring, the voltage signal remained at 1.66V. During this task, if the reading does not change, this indicates that you’re not on the correct branch of the circuit that has the short. Remember, we’re dealing with a parallel circuit here.

Lab Scope

When I started testing the wiring under the hood by the firewall, the voltage pulse had already dropped to 1.11V. The closer I got to the front of the vehicle, the smaller the signal pattern became. Finally, at the right front lights, the scope recorded a voltage pulse of .3V. I knew I should start looking for the problem in that area. I spotted this vehicle’s problem at the right front turn signal light. The wiring harness was pinched near the right front light and shorted to ground.

Voltage Signal

One thing you must realize here is that the voltage signal pulse will give you a sense of direction. In my case, the voltage signal of 1.66V indicated that the grounded part of the circuit was a good distance away from where I was testing. But the low-voltage signal of around .3V meant I was very close to the grounded part of the circuit. If I had passed the location of the short-to-ground in the wiring, the scope signal would have disappeared.

Scope Pattern

Let me explain the cause of the change in the voltage signal. With the front light grounded, that part of the circuit is under a momentary load and operating. The scope picks up the voltage drop pulse of the wire at that particular point in the harness or connection. The rear wiring is not operating directly under load, but that branch of the circuit is still affected by the problem. This is why the rear wiring signal pattern remained the same at different points in the circuit.

When you encounter two or more wires of similar color in the harness, the generated scope signal will identify the correct wire. Only the grounded circuit wiring will have the pulse signal. That makes circuit diagnostics a lot easier. Also, if you disturb the portion of the wiring that’s causing the problem, the flasher and light may stop flashing. So in effect, two types of tests are being performed at the same time.

In conclusion, when troubleshooting a short-to-ground, begin by determining the starting voltage signal at the fuse box. Circuit design, along with the short-to-ground location, will affect the starting voltage pulse. If you have to probe the wire directly at different points, the pinholes that were made by the test probe lead must be resealed. Last but not least, note that this procedure should be used on fused circuits only. Attempting it on 5V reference circuits can damage the computer or related components.

 

I replaced a rubber grommet on my passenger blinker plastic housing. Blew out another fuse under the dash fusebox. Hazards work great. But signal lights wired to aftermarket bumper popped 2 fuses already?

 

Look to see if she has a trailer tow adaptor harness... those things are always causing problems.