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voltage spike

3538 Views 10 Replies 4 Participants Last post by  BighornSheep
heres my problem. im driving down the highway, goin 110-120km/h, and all of a sudden, my voltmeter gauge spikes up to past 18! i have to shut the truck off, and restart it to make it go back to normal. it does it about every 20 minutes, and only on the highway. one time my fuel gauge dropped down to empty too. a simple restart and it was fine.
has this happened to anyone?
also, could my smarty be the cause of this?
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Discussion Starter · #3 ·
well yeah its pretty straight forward of what it COULD be, but i need some people who have experienced this problem, or know what to do to fix it
 

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Discussion Starter · #4 ·
i have fresh corrosion on my driver's side battery terminal. high voltage and corrosion, possibly due to battery overcharge? so this points to my regulator going bad on the highway (larger load on the engine, charging system).
just my gatherings.
can one buy and replace an alternator regulator, or does the whole darn thing have to be replaced?
 

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Discussion Starter · #6 ·
well i hooked up an external voltage regulator, and it is still acting up. this is driving me bananas.
where is the guage cluster relay located?
also all thats really left is the alternator is faulty... :banghead:
 

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Hey just wondering if you resolved your problem and how because i am having the same issues with overcharging, even after replacing the alt and both batteries
 

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Discussion Starter · #9 ·
does it spike, or is constantly high? one of the bolts that hold down the main alternator fuse was loose, that was my problem!
 

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it spikes, anything above 2rpm the voltage meter pegs out, but when running less than 2 it stays at its normal position, i have checked for lose wires but found nothing abnormal
 

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Discussion Starter · #11 ·
MIGHT be your voltage regulator. thats about as much as i can help you. since the alternator is spinning that fast, and the regulator isnt working to reduce the field current, it will cause it to spike? my theory
 
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