I've done some searches of Tech and Archives on "short(s)", "electical" and "multimeters", but still have some questions ... I'm really a Noob with electrical systems <img src="/forums/images/graemlins/shiner.gif" alt="" />

My ECU keeps throwing a CEL; code 0440 Evaporative Emmissions System. Truck runs fine (or seems to <img src="/forums/images/graemlins/rolleyes.gif" alt="" />) but that CEL is damned annoying.

In any event, I took my rig to the stealer to see what they could tell me about the code. After plucking $45 from my wallet they told me there was a short in the wiring and that the harness would have to be replaced ... $300 <img src="/forums/images/graemlins/ignore.gif" alt="" /> <img src="/forums/images/graemlins/shame.gif" alt="" />

With a "short" I guess I'm looking for chafed, melted or burnt wires?

Is there a way to find a short with a multimeter? I bought one and am currently reading the manual to try to figure it out <img src="/forums/images/graemlins/drunk.gif" alt="" />.

How do you fix a short? Assuming it is a simple chafe of the wire - would I just put electrical tape around it and call it good or is there a better way / product.

I read in one thread about soldering the wires together and heat shrink wrapping the joint. Is this the preferred method?

What tool do you use for soldering and what material to you use as solder (not sure if my terminology is correct here)?

Any insights you could give me would be greatly appreciated.

Thanks! <img src="/forums/images/graemlins/kewl.gif" alt="" />

P0440 is the code that will give you a CEL when your gas cap is loose. Could be that you have a short, then again tightening your gas cap couldn't hurt and it won't cost you $300. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Yeah, forgot to mention that part ... they tested the cap ... it's good to go and I always put it on until 'click, click, click'

Good point though.

Here's an example of how you would do it, but may not apply to your scenario: You can use a multimeter to test for continuity between two wires that should not have continuity, if they do they must be shorted by touching.

Say you know the short is blowing a fuse on a certian circuit, you can unplug the harness from a certain point, and disconnect the battery. If you know by reading the wire diagrams, that two wires are entirely seperate circuits, and they have continuity (a zero reading of resistance) than you know they are the problem.

Set the MM to resistance, the ohms symbol. When current can flow from the red to the black on the test probes, there is continuity and you will get a reading. The default would be infinite resistance.

if the dealer is right, you are going to have to figure out the construction of the evap emissions systems and its wiring.

chris

Thanks Chris - I have the Helms manuals for trouble shooting electronics and the emmissions systems <img src="/forums/images/graemlins/kewl.gif" alt="" /> (been reading up on them over the past two days ...)

In any event, I got under the truck, took a look at the EVAP purge solenoid and the short was obvious!! <img src="/forums/images/graemlins/shocked.gif" alt="" />

Right where the two wires leave the plug to the solenoid ... ZAP!! ... the BLK/YLW wire was burnt in half and there was a chafe in the RED/WHT wire right next to it <img src="/forums/images/graemlins/rolleyes.gif" alt="" />.

Problem now is finding a suitable harness plug replacement <img src="/forums/images/graemlins/confused.gif" alt="" /> ... see here to help

Also, does anyone have any info on soldering these wires?? What tool and what type of clips or solder to use?

Thanks again. <img src="/forums/images/graemlins/kewl.gif" alt="" />