[Stxguy26]

Just got a free tacoma to beat around in. But theres a wire overheating and melting under the hood. Ive traced it the best i can but my box cover is missing the label to the relay the burnt wire is from, the bottom right one in the picture.

The wire then goes the this white block that looks like it connects it to all the other white and black wires.

If anyone can help me out with what this is supplying power to so i can get this truck back up and running without being a fire hazard id appreciate it.

Also am i under the right assumption that an overheating wire is either a loose connection or a part drawing too many amps. Not that knowledgable about dc power compared to ac power.

 

[Stxguy26]

It seems most of these wires are tied into the headlights and blinkers in the front. Im assuming the wires going to the rear would be for tailights and blinkers? Could a bad bulb or fixture cause one wire to melt? Is there a relay that controls all exterior lighting? Im not seeing any melted wires going anywhere else, besides between relay and white block.

 

[Enola Gaia]

I'm having trouble understanding which connection is the overheated / burnt one. If I'm understanding your description correctly it's the Heater Relay.

Here (attached) is the 1995.5 Tacoma relay locations section, which includes illustrations for the relay and fuse locations (p. 19).

 

[Stxguy26]

Very strange, multiple wires from that block go to headlights and turn signals. With 3 of the white with black stripe going through the firewall to the rear.

What would the heater relay power? The blower? Or a valve that opens to circulate the coolant through heater core? Is there an electrical element?

Im very confused now.

 

[Stxguy26]

Also actual date on doorjam is 02/95 is that changes anything.

 

[Stxguy26]

Also i live outside of the us so it may not be a us market tacoma either but it is a high likelihood. Ill check tmw for sure.

 

[Enola Gaia]

Also actual date on doorjam is 02/95 is that changes anything.

It's no problem ...

The first Tacomas were introduced as mid-year 1995.5 models. Production of these new models at NUMMI in California began in January 1995.

 

[Enola Gaia]

Also i live outside of the us so it may not be a us market tacoma either but it is a high likelihood. Ill check tmw for sure.

The Tacoma was a North America specific model. The only variations were US versus Canadian market versions. The layout of the fuse / relay block in the file I posted is given for both versions.

Daytime Running Lights (DRLs) were standard equipment on Canadian models only in 1995.5. I can't verify whether or not DRLs were offered as an option on US 1995.5 models.

If you don't have the DRL Relay, it's definitely a USDM model.

 

[Enola Gaia]

Here (attached) is the 1995.5 power source / power flow diagram and chart, as well as the heater / air conditioning circuit diagram. The Heater Relay controls power to the A/C switch (if your Taco has A/C).

 

[Stxguy26]

Ok, thats exactly what i needed. It appears its a ground that is melting. At terminal 2 on the heater relay going to the junction block, where it ties into other grounds it looks like.

So again excuse my ignorance, if a small ground wire is overheating that means one of the main larger grounds is not making a good connection so its forced to go through the small one?

Also where are you sourcing these schematics? Ill need wiring under steering wheel, just to check everything out. There was at some point a stereo in the truck and theres a lot of splices and cut wires under there making me nervous.

 

[Jimkola]

On the door jam where the VIN is there is also a model#. If the model# ends in "A" then it was built for the U.S. market. "K" is Canada. Go figure.
Someone gave you a electrical basket case. Pulling the covers off the relays in the fuseblock is a sign of both desperation and lack of electrical knowledge.
I'd focus on anything that isn't factory first. Especially tow wiring, aftermarket stereo stuff(especially if a aftermarket amp is involved), alarms, etc. At the very least disconnect, but I'd probably remove. I'd also repair all the wiring where the sheath has been exposed. Personally, I'd shrink tube, but anything is better than nothing.
I'd also replace the relays that have the missing covers.
99% of the electrical issues we dealt with that were huge problems could be traced back to improperly installed accessories, especially stereo. Those guys would run tap screws just about anywhere without checking what was on the other side.
Keep us posted as you dig deeper

 

[Jimkola]

The wiring diagrams in the FSM are good. The best is the EWD manuals(Electrical Wiring Diagrams) manual that were a supplement to the FSM. It gives bigger and better diagrams, along with diagrams of the connectors and pin locations. They can often be found on eBay. Most sellers price the EWD in the $75-$100 range, but if you're patient you can sometimes get a good deal from someone who just wants to move books and manuals. I got mine for $20