gm spark plug wires [Archive] - The Donzi Registry

mikev

10-31-2008, 08:28 AM

2000 Yukon XL with the 5.3 V8 its got the short plug wires since there is once coil per plug. my question is the resistance on them when i checked them yesterday was between 600 - 800 ohms seems really high for wires that are 6"-8" long but I could not find any specs for them. anyone have an idea as to what they should be?

cutwater

10-31-2008, 08:38 AM

I have no idea but I'm pretty sure it's not 800 ohms... A conductive wire will typically read 300 to 500 mOhms on an ohmmeter, mainly due to contact resistance. Are you sure your leads are making a clean contact?

chappy

10-31-2008, 09:12 AM

I read 350 per foot is the norm.

zelatore

10-31-2008, 09:15 AM

I believe the 350/ft seems about right, but wouldn't be surprised to hear something different on late-model engines. Remember, this isn't a 'straight wire' - nobody's been using that for years. It's all about noise surpression.

cutwater

10-31-2008, 09:34 AM

Oh yeah forgot they are using high carbon content in the plug wires. Always wondered whether they should have just looked at better RF shielding methods rather than reducing spark efficiency. Regardless I would say 350ohms/ft is reasonable.

mikev

10-31-2008, 09:48 AM

MOP

10-31-2008, 10:10 AM

Post your question here, they may very well be bad but here http://www.gmtruckclub.com/forum/index.php you will get the correct answers from GM techs.

A-P.S. I was going to upgrade my wires to 8mm, my bud at the non GM repair shot said don't do it that it may affect the computer.

mrfixxall

10-31-2008, 11:35 AM

Mike,those wires will last up tp 150k gm reccomends replacing them at 100 k.

If it were me i would replace them,even tho they may look good? get them wet then ohme them out and see where your at..

Ac delco only!!!!!!!! other wires will have a higher ohme rating..

Conquistador_del_mar

10-31-2008, 12:08 PM

sounds like there ready to be replaced let me make sure I did the math right before I spend the 50 bucks for set. I set the mulitmeter to read ohms at 200 and it maxed it out at 1.00 so I stepped it up too 2k and got readings around between 0.390 and 0.465 so multiplied it .390 and .465 times 2000 and got 780 ohms and 930 ohms respectively is this right?

Your VOM should have a scale that matches your settings. See if you don't have a scale that maxes out at 2,20,200 or 2000 - that is the one you should be reading. You should not have to do any multiplication. Bill (former electronics engineer)

mikev

10-31-2008, 01:06 PM

Your VOM should have a scale that matches your settings. See if you don't have a scale that maxes out at 2,20,200 or 2000 - that is the one you should be reading. You should not have to do any multiplication. Bill (former electronics engineer)

mine has 200 then 2k when i did 200 it read 1.0 when i set it to 2k is when i got the readings above. maybe i am using it wrong i will get my electrical engineer buddy to look at it this weekend. i will replace based on mr fixitalls advice since truck has 156k and they are gm so probably the orignal wires.

zelatore

10-31-2008, 03:59 PM

i will replace based on mr fixitalls advice since truck has 156k and they are gm so probably the orignal wires.

156K on the original plug wires? I think you're making a good move there just replacing them anyway. Call it cheap insurance.

mrfixxall

10-31-2008, 04:15 PM

mine has 200 then 2k when i did 200 it read 1.0 when i set it to 2k is when i got the readings above. maybe i am using it wrong i will get my electrical engineer buddy to look at it this weekend. i will replace based on mr fixitalls advice since truck has 156k and they are gm so probably the orignal wires.

Get yourself a tube of dielectric greece too and lube the ends up:wink: