Author Topic: Voltage spike...?  (Read 32414 times)

Offline 454Man

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Re: Voltage spike...?
« Reply #15 on: August 07, 2013, 03:47:46 PM »
The problem just started happening out of the blue. it happens mainly if I let the truck sit for more than 3 days. Out like I said b4 if three is to much amp draw inside.The headlights don't cause the prob.

Offline 454Man

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Re: Voltage spike...?
« Reply #16 on: August 07, 2013, 04:26:33 PM »
When this happened one time I pulled all the fuses out the fuse box(to rule out those accessories) and it still continued to peg the volt meter.

Offline 454Man

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Re: Voltage spike...?
« Reply #17 on: August 07, 2013, 08:22:47 PM »







Online bd

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Re: Voltage spike...?
« Reply #18 on: August 07, 2013, 09:18:30 PM »
I see a couple of wiring problems you'll need to correct later.  First things first...

I need to know exactly where the "red" and "white" wires that plug into the regulator tie into the cab wiring.  As you follow the wires, physically inspect the harness for damage and the condition of terminal ends, splices and connections.  Post pics of where the wires connect. 

Do you have a voltmeter and test light?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 454Man

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Re: Voltage spike...?
« Reply #19 on: August 07, 2013, 10:02:01 PM »
I have a  fieldpeice multimeter and use it daily for my job :-) I have a couple things bypassed as a way to rule out things. I've ohmed wires all wires under the hood and replaced the ones that showed any resistance or (OL) next I'm gonna add a 4 or 8 gauge wire from the alternator.then maybe the fuse box from another truck that looks good. Any thoughts?

Offline 454Man

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Re: Voltage spike...?
« Reply #20 on: August 07, 2013, 10:10:49 PM »
Just added that engine to frame ground. Will see if that helps tomorrow
Does the fuse box split in half? Like one side in the cab and the other under the hood on the fire wall? I'm looking at it and can't tell.
« Last Edit: August 07, 2013, 10:13:01 PM by 454Man »

Offline Irish_Alley

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Re: Voltage spike...?
« Reply #21 on: August 07, 2013, 10:57:06 PM »
theres one bolt i think 10 mm just took one off and i dont remeber what it is. its a common problem for these to be melted and might cause a problem or two.
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

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Offline 454Man

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Re: Voltage spike...?
« Reply #22 on: August 07, 2013, 11:02:33 PM »
Ah yes... some reason I thought that was some kinda old sealant maybe mine is melted I'll take a pic tomorrow. So one bolt? Does three box come out I'm two parts or one? Thanks.

Offline Irish_Alley

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Re: Voltage spike...?
« Reply #23 on: August 07, 2013, 11:12:29 PM »
the one bolt is on the engine side and it acts like a quick connect. the wire harness will stay under the hood and the fuse box part will stay in the firewall
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

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Online bd

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Re: Voltage spike...?
« Reply #24 on: August 07, 2013, 11:23:53 PM »
I have a  fieldpeice multimeter and use it daily for my job :-) I have a couple things bypassed as a way to rule out things. I've ohmed wires all wires under the hood and replaced the ones that showed any resistance or (OL) next I'm gonna add a 4 or 8 gauge wire from the alternator.then maybe the fuse box from another truck that looks good. Any thoughts?

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.

The bulkhead connector is a three-piece assembly.  The engine harness is secured to the connector using the screw Irish mentioned.  Inside the cab the connector is secured to the firewall with two long screws that also piggyback the fuse box onto the connector.  The two connector halves are sealed with a black tar-like antioxidant.  The #1 regulator lead is a resistance wire.

Still need to know where you have the regulator wires connected into the cab harness.
« Last Edit: August 08, 2013, 11:56:24 AM by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 454Man

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Re: Voltage spike...?
« Reply #25 on: August 08, 2013, 07:38:25 AM »
I added anothere ground from the engine to the frame and so far all is well. I'll give it a couple days though. I'll trace those wires bd I'm sure there going to the factory location as the truck was all factory b4 I swapped the engine, all down to the smog stuff
« Last Edit: August 08, 2013, 07:49:10 AM by 454Man »

Online bd

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Re: Voltage spike...?
« Reply #26 on: August 08, 2013, 09:54:01 AM »
Happy day!  Glad to hear the engine ground resolved it!

Some additional information:
The two wires from the regulator serve the following purposes: The #1 lead is the "exciter circuit" connected to ignition power through a resistance (either a resistance wire w/ factory gauges, or the charge light w/o gauges).  The resistance is important to prevent the alternator from trying to charge the battery through the small gauge ignition circuit under certain circumstances.  The #2 lead is the "sensing or regulator circuit" connected to battery.  It senses system voltage so the regulator can adjust alternator output to maintain a target charge voltage of 14.2 volts (13.8 - 14.5 volts is the acceptable range).  Ground is the zero reference the regulator needs to accomplish its task.  A fault (unwanted resistance) in any of the three circuits will defeat the regulator's purpose.  Make sure that you crimp, solder and heat shrink all terminal ends and splices as you work your way through the electrical system for the best results over the long run.

Well done!
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline 454Man

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Re: Voltage spike...?
« Reply #27 on: August 08, 2013, 11:13:14 AM »
Thanks for the info I'll post any results in a few days

Offline 454Man

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Re: Re: Voltage spike...?
« Reply #28 on: August 08, 2013, 11:15:52 AM »
the one bolt is on the engine side and it acts like a quick connect. the wire harness will stay under the hood and the fuse box part will stay in the firewall
thanks

Offline 454Man

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Re: Re: Voltage spike...?
« Reply #29 on: August 08, 2013, 12:43:26 PM »
On the ground idea. Guess I could add some more. Can never have enough. I have the small one from the Neg Batt cable to radiator support. Neg Batt cable to alternator, ground strap to firewall and that's it what else do I need? Again thanks :-)

You're missing one.  There should also be a ground strap from the front of the driver's side head of the engine to the frame rail.
thanks!