Voltage spike...?

[454Man]

Volt drop test it is

[454Man]

I noticed the positive Batt wire sits real close to the engine block. Maybe it's heated a gone bad. It don't look that old at all

[bd]

As a sidebar:
Copper is unaffected by the heat radiated from an engine, although ozone, heat and chemicals can attack the insulation.  Damage to copper cables is usually a result of battery acid wicking down the cable or salt wicking up-cable from the starter - the result is very green and the cables become rigid with salt buildup inside the jacket.   

If the cables are original GM, they may be copper-clad aluminum.  Aluminum cables gradually increase in resistance over time and should be replaced with solid copper cables when service becomes necessary due to voltage loss across the cables. 

IMO - The best choice for most of our trucks is 1 or 0 all-copper stranded cable with terminal ends tightly crimped, soldered and shrink sealed.

[Irish_Alley]

just curious but whats the reading on the signal wire to the alt? when its not overcharging and when it is

[454Man]

Sorry for the delay. Family first ya know. BD and zieg now I think about it I sent my starter back to summit, cause I thought it wouldn't start my truck, so it may just be the Post Batt wire to the starter

[454Man]

I'll get some readings thurs my day off. Thanks guys

[zieg85]

Sorry for the delay. Family first ya know. BD and zieg now I think about it I sent my starter back to summit, cause I thought it wouldn't start my truck, so it may just be the Post Batt wire to the starter

I've found my fair share of really good looking green corroded wire in amongst the bright red insulation.  The least little bit of starter drag, or charging issues I automatically check my engine to cab and engine to frame grounds and if are sound I put a new positive cable on it.  For no more than they cost it is a good practice if they have any age on them at all.  I'd say a good 90% were green with corrosion...  1 or 2 were alternators, a couple were dragging starters and 1 had a bad cell in the battery.  Funny thing it started the car fine but all kinds of issues cropped up...  This is from 20+ years and 300+ cars and trucks...

[454Man]

Sounds about right. Thursday I'll check and change the + Batt write and alternator charging wire. What sizes do you guys recommend?

[bd]

Sounds about right. Thursday I'll check and change the + Batt write and alternator charging wire. What sizes do you guys recommend?

For the battery cables:

... IMO - The best choice for most of our trucks is 1 or 0 all-copper stranded cable with terminal ends tightly crimped, soldered and shrink sealed.

For the alternator charge lead:

... If the alternator is rated less than 70 amps output, build the charge lead from 8-ga wire; between 70 and 100 amps output, use 6-ga wire; between 100 and 150 amps output, use 4-ga wire; over 150 amps out, use 2-ga wire.  Protect the charge lead with 6" of the appropriately sized fusible wire at the charge lead's battery connection.  Crimp then solder all terminal ends....

Route the alternator charge lead directly to the battery through a 6" length of fusible wire at the battery end.  How to make a Fusible Link.

[454Man]

Thanks a lot!

[454Man]

Thick or thin stranded wire?

[bd]

Thick or thin stranded wire?

For the battery cables, thin stranded wire is welding cable.  Welding cable is expensive and unnecessary unless you need flexibility along the length of the cable run.  Welding cable is great for jumper cables - overkill for stationary wiring.  On the smaller cable I think it amounts to personal preference and what's available.

However, I recommend using SXL or GXL insulated primary wire, because it is significantly more resistant to heat and underhood chemicals, ozone, etc.

I neglected to mention earlier, run the #2 regulator lead directly to the output post of the alternator.

[454Man]

Sounds like a game plan now I'll have to check the parts stores for the wire

[bd]

Most parts houses won't carry SXL/GXL wire, because it's more costly and many techs don't know the difference.  GPT or PVC thermoplastic insulated wire may be all you'll find.  But, you can order SXL/GXL:  Del City or Terminal Supply Company, etc.

[454Man]

Ok I'll try and find a place that sells the cable by the foot or in five foot sections. So far idk...