Hoping one of you experts in electrical can help

I am installing a power point inside the engine compartment of my Screw. I have a white (-) and a gray (+). I inserted an inline 20 amp spade fuse on onto the gray wire. I have positioned the unit onto the battery cover on a clear vertical side (plastic). The gray wire goes to the pos side of the battery, the neg goes to ground. Doesn't work. Tried putting the white wire to the neg post on the battery. Still doesn't work. Checked the fuse, although old, looks in good condition. (8 years old). The spade fuse by the way is the large one. I can't figure out what is wrong, aside from the fact that I admit to being a bit of a klutz when it comes to wiring.

Any help would be appreciated.

 

Ohm Out The Fus To See If It Is Good

 

I'm no "expert" but simply try process of elimination.

First of all what do you mean by "doesn't work"? How are you testing this exactly? Also, I'm curious as to how you're grounding the white (-) wire. Running it straight to the battery (-) or onto the chassis?

 

Please, you don't "ohm out" anything, you check it for continuity.

2 minutes with a test light should track down the problem. Whichever wire is connected to the center terminal on the power point should go to the positive side of the battery. Use the test light to see where the voltage stops and you'll have the problem.

-Joe

 

I am using a portable air compressor to test to see if it works. The compressor works on the cigar lighter inside the truck, but doesn't work on either power points, in the dash, or in the rear seat of my screw.

I have tried grounding using the battery post (-) and to a grounding strap inside the engine compartment. Neither positions work. Do you think I should run the white wire to a separate ground elsewhere on the truck?

It has me baffled.

 

That really is pretty strange. I was curious since a good ground is always an issue. Are we pretty certain the power point itself is functional?

 

Pick up a cheap $3 test light from the local auto parts store. I've got one in each vehicle and one in the garage. They're the best way to troubleshoot this. 2 minutes and you'll know EXACTLY where the problem is. Clip the alligator clip to a ground, then use the tester to probe.... first the connection at the battery, then the wire that comes into the fuse, then the fuse itself, then the terminal inside the power point. Then switch the alligator clip over to the positive side of the battery and check the ground of the power point for continuity to ground.

Like I said before, 2 minutes and you'll know EXACTLY where the problem is.

-Joe

 

Oh, and the auxiliary power points are on their own fuse, separate from the cigar lighter plug. It's a 20A fuse (can't recall which one offhand) I've managed to blow mine every time I've used the compressor at the dunes. As the motor gets hot, the resistance drops and it draws more current. Eventually it draws enough that it blows the fuse.

-Joe

 

ohm it out and checking the continuity will result in the same out come

 

What does "Ohming out" mean?
Dude! I wanna Ohm out this spankin hott chick from school.

 

it will check continuity and give you the resistance reading of the switch or control. pressure controls and maf sensors have a resistance they need to put out to operate properly.
when you ohm out you just need to make sure there is no voltage applied to the control or you will blow the fuse in the ohm meter

but is she hot!

 

"Ohming out" is the same as checking for continuity.

 

I know what you mean by "ohming it out" but the proper terminology is "checking for continuity". An Ohm is a unit of resistance.

"ohming" something out would be like saying "inching" something when you want to measure it, or "degreeing" something instead of measuring the temperature.

Measuring resistance in Ohms and checking for continuity are two slightly different things. The tool is the same, but when checking for continuity, you simply want to know if there's a connection there. The actual resistance measurement (in Ohms) when checking for continuity is irrelevant.

I'm splitting hairs and hijacking a thread.... it's just one of my pet peeves.... sorry.

-Joe

 

i know the difference . i just didnt think it was worth explaining the differnce .
didnt want to confuse those who do not have a very good electrical background

 

GI, I know you not going to like this but testing continuity IS no different than checking resistance, in reaility, if you want to make it simple.
For example if a lamp continuity is tested with a voltage source and a voltmeter to measure that voltage thru the lamp, it is no different than measuring with the Ohm function in the meter that has it's own battery, internally and accomplishing the same thing but giving more information.
The lamp has resistance in either case.
Sometimes continuity testing will not show a resistance that is still to high to work in the circuit.
I also know all the differences.