Intermittent IG1 No2 Fuse Blowing

Hi, first post! Hopefully someone can help... I've been having the same recurring issue for the past year and no shop can fix it. The IG1 No2 fuse will blow intermittently for seemingly no reason leaving no speedo, no window power, no fan, and a cluster lit up like a xmas tree! Also, the alternator then stops charging and battery dies if you continue to drive. The code reader says P0500 and no other errors. It's a 2013 double cab short bed 4x4.

It's very frustrating as the randomness means I'm reluctant to take my family in it, especially up the mountains in summer.

 

Welcome to TW. Almost all intermittent problems on vehicles are caused by a connection issue and even for us technicians they are very hard to diagnose due to their random nature and inability to duplicate the concern while testing. Unless there is some sort of pattern failure issue for this on tacomas I doubt there is much we can do for you. P0500 is for Vehicle speed sensor. I am not sure if that is the speedometer sensor on the trans or if that is an Wheel speed sensor for the ABS. By the wording I would think it would be for the trans. What have the shops you have taken it to all done/said?

 

I couldn't replicate the issue when it was in the shop and either could they. They looked for shorts and worked their way through various systems on that fuse but no luck. The guy was super helpful and genuinely wanted to solve the issue but just couldn't.

 

check your ac clutch magnet and make sure it hasn’t rotated and pinched the power wires against the compressor housing.

 

This is what my issue was. I incorrectly replaced my AC clutch magnet and caused it to short out because the coil melted. Every time I turned the fan on it blew the fuse.

 

I have had the issue also and narrowed it down to being related to the ac compressor. I assume it was the magnetic clutch failing. When I would tow, I just made sure to turn the ac off before down shifting and spiking the rpms. Haven't gotten around to replacing the clutch, but I have other signs now it is failing/failed (smoking belt intermittently at start up).

 

My uneducated visual inspection showed no pinched power wires. I checked every wire I could find in the engine block to look for signs of wear or possible shorting but again, all looked fine.

The only aftermarket add-on was a remote starter if that info is of any use

 

Could be a internal short in the ac mag.
Get a fuse diagram to see all the circuits on that fuse. You know most of them cause they ain’t working. Lol
Then systematically run the vehicle and try every circuit 5 times and see the results. If you can, do not run ac hvac system for a couple of days. I guarantee a coordination between something turning on and everything else sitting. Basically what you are doing when your driving. Make sure everything is shut off
While driving and work one circuit. Then while driving turn on the ac, then shut it off after 5 min. Wait 5 and turn it back on. At some point you will hit the right combo. Don’t use multiple circuits at once.
Be very precise. I had to take a cust truck home for two days and drive it until I got the right combo.
FYI those two wires out of the clutch magnet needs to be centered in the recess of the housing. If it’s not centered then you have a issued there. Make sure the engine is off and use a screwdriver to play with that magnet. If it moves it’s trashed.

 

Thanks Mike, really appreciate the help!

 

I’ve had a couple and it does suck the first or second time. That’s what the little black book is for lol.

But being precise will help you narrow it down

 

Also, the short only happens when the fan or AC is running - sometimes immediately, sometimes after a few minutes, other times right in the middle of a long journey.

 

Dam,would have saved me a bunch of typing if you had said that from the start.

 

Sorry dude!

 

That’s ok.
After 48 years I got use to fixing shit in the blind..

 

Following up on this issue: after reading every thread I could find, I changed out the blower and the resistor in the hope this would solve the problem. No dice. Took it for a test drive and switched the fan on, fuse blew within seconds and lost speedo, windows, etc.

Any ideas for next steps @Tacoma Mike ??

 

If it only blows when the A/C is switched on I bet it's a shorted compressor clutch or shorted wire between the compressor and engine bay fuse box as @Tacoma Mike said.
I would want to put a clamp on amp meter on the A/C clutch wire and see how much current it's drawing when it's turned on.

 

Could check your IA4 connector in the driver's kick panel. It is probably smoked like mine. Could be melted bad enough it is shorted to another wire in the connector.