voltage drop on acceleration

[techieman33]

The gates belts are really nice.

 

[storlied]

Tensioner is pretty damn tight, always has been. I'll check on the gatorback as suggested by Celly, I keep reading nothing but good about them, and about how quiet they are.

 

[Mbrooks420]

Does the tensioner spin freely, and true?

 

[storlied]

Huh?.... I mean the tensioner is as tight as it has always been, as far as the pullies... everything is smooth, no play in any of em.. no grinding.. (well id hope not.. haha) new issues (yea yea, I know...) oil pressure is reading High?... that doesn't make sense if the belt is slipping......?....

 

[Mbrooks420]

It's not like the oil pump is belt driven. Also your "oil pressure gauge" isn't an oil pressure gauge, (unless you added one) The factory is just a on or off switch just light a check engine light.

 

[storlied]

Thought the pump was belt driven, guess not. It was weird, if I was on the break.. it would go down just a lil bit toward the middle... but once I let off the break and the truck started to roll it would raise a little bit..... what an odd gauge...

 

[storlied]

New belt, ended up getting the Gates, came with a 1 yr warrenty. Problem seems to be gone, still getting some odd lower voltages but it's charging the battery better... I do believe I need to replace the wire coming from the power dist box to battery... something that always confused me was how the alternator powered everything... it has a black cable running to what you'd think was the negative to the power box.. but it just goes through the box and to the battery.. they should have just had two red wires run through it... after tearing all of the electrical tape and those black tubes from the battery cables they don't seem so complicated afterall... all my cables seem pretty good except the cable I mentioned earlier... so either I'll replace that one or cut it down more and see if it's still good beyond the frayed part. A new terminal wouldn't hurt either.. these aftermarket ones seem to corrode faster... I'm gonna look for a heavy duty one.

What voltages are you guys running at idle? And battery voltages with the truck off?

 

[BrooklynBay]

http://en.wikipedia.org/wiki/Alternator

 

[storlied]

What are you trying to point out?

 

[BrooklynBay]

I thought that you wanted more information on how an alternator works?

 

[storlied]

I know how it works, I was just stating on how I got confused because of how they had the wiring harness all wrapped up, made it a little confusing.

I think I may remove the box to battery cable, and leave the alt to box cable and run a 4g wire from the alt also straight to the battery... along with beefier grounds... pretty much the Big 3 mod.. Do you think I would see any difference having the box connected on it's own wire not sharing the alt to battery cable?

 

[storlied]

I know how it works, I was just stating on how I got confused because of how they had the wiring harness all wrapped up, made it a little confusing.

I think I may remove the box to battery cable, and leave the alt to box cable and run a 4g wire from the alt also straight to the battery... along with beefier grounds... pretty much the Big 3 mod.. Do you think I would see any difference having the box connected on it's own wire not sharing the alt to battery cable?

Edit: Nvm.. that would leave me stranded... lol... Anyways.. I'm gonna do the Big 3 and replace/repair the damaged part of the harnesss along with a new HD terminal and I think I should be good to go. I do run a good amount of electronics... wouldn't hurt to give my old small wiring a break. The relays for the highs and lows was a good mod definitely.

 

[storlied]

Alright... I'm gettin a lil pissed at this point.... no change... it's still overheating, oil pressure is high and I'm getting next to no charge when I'm driving around.... Although.. if I punch the gas from a stop.. it'll read a good 14v for only a second.... brand new belt... any other suggestions? Next logical thing would be the tensioner but it's very tight, no play at all in any of the pullies either... so... I'm lost..

 

[2000StreetRod]

Voltages

... I do believe I need to replace the wire coming from the power dist box to battery... something that always confused me was how the alternator powered everything... it has a black cable running to what you'd think was the negative to the power box.. but it just goes through the box and to the battery.. they should have just had two red wires run through it... after tearing all of the electrical tape and those black tubes from the battery cables they don't seem so complicated afterall... all my cables seem pretty good except the cable I mentioned earlier... so either I'll replace that one or cut it down more and see if it's still good beyond the frayed part. A new terminal wouldn't hurt either.. these aftermarket ones seem to corrode faster... I'm gonna look for a heavy duty one.

What voltages are you guys running at idle? And battery voltages with the truck off?

According to my Haynes Repair Manual the battery voltage should be about 12 volts when the engine isn't running. Mine reads 12.6 with ignition OFF. Haynes specifies that the "B+" and "A" terminals on the alternator should read 14.0 to 14.7 volts at 2000 rpm and the "I" terminal should read 13.0 to 14.0 volts. The "A" and "I" terminals are on the voltage regulator on the alternator.

Typically there are fusible links inline between the alternator and the battery. If you replace any of the wiring make sure you include a fusible link if applicable. A faulty link could also be your problem for the voltage drop but it doesn't explain the corresponding overheating. Unless the low voltage is causing the gauge to erroneousy indicate a high temperature. I would think just the opposite would be the case - low voltage results in low temperature. Are you convinced that the voltage drop and the overheating are related?

 

[storlied]

Well, I'm not 100% positive but that original belt was cracking all the way through... when I'm on the gas I'm getting a typical voltage read of 12.6, unless I punch it from a stop then I get 14v for just a moment... and overheating.. I don't know any reason the engine would overheat... it acts like the voltage does.... it's quicker to get back to normal when I'm slowing to a stop.... you'd think the lack of airflow from sitting still might make cool down take longer.... new belt... everything is on the pullies right.... I read online that tensioners have marks on em to show where they should be at...the tensioner has no movement when the engine is revved... anything I should know about the V8 tensioner?... I think that should be the next replacement to be honest, as they say change it with the belt... and all of this seems like it is probably the tensioner from my symptoms....

 

[storlied]

Gavin is leaning toward the tensioner still being good, very very little slack in the belt when I push and pull on it.. no slippage noises.... what would cause cooling and voltage both to just die when I'm driving, but not at idle? His original tensioner has 180k on it .. I'm starting to think it might not even be my prob.. But just these symptoms .. I just don't know:

12.6v driving
13.0-13.2 idle
14v when I punch it from a stop (only for a moment)

overheating when I'm on the gas at highway speeds (when the voltage is sitting there at 12.6) It seems when the voltage is low, the cooling is nonexistant until I get that voltage back up by getting off the gas n stopping to let it idle...

 

[2000StreetRod]

Water Pump?

Is it possible that the water pump bearing is worn and causing enough friction that your serpentine belt slips? If it's dragging and turning slowly as you accelerate it might explain the dropping voltage and the overheating. At idle it may be keeping up but gets behind at higher rpms. Did you check to see if everything that's on the belt (except the crankshaft pulley) turns freely? If so, did you actually turn the water pump pulley or just the viscous fan?

 

[storlied]

I'll re-check tomorrow... these issues are getting bad... and whats with the oil pressure gauge?.. It'll read high at a stop.. but once I get on the gas it'll drop quickly to normal and make its way back up to the high reading.. I had a voltmeter earlier for a moment and I'm getting 13v from the alt.. no loss in voltage through the fuse box to the battery.. it all reads the same.., but it's low... I can't even get it to go for 14v anymore... I'll be re-checking all my pulleys tomorrow asap.

 

[Mbrooks420]

As stated before your oil pressure isn't reading high. Your "oil pressure gauge" is no more than a check engine light. If it reads more than 5 psi it is supposed to read normal. The gauge is probably being messed up by the voltage fluctuation. I'm with 2000Street rod, check out the water pump.

 

[storlied]

Checked water pump (pully that drives the fan, correct?) and it spins smoothly)

Would a bad ground anywhere give me a loss of a volt from the alt?

All pullies spin smoothly..

Edit: I was messing around a lil bit, I disconnected the neg from the battery while the truck was running... and my voltage was gettin to around 14v or so... what would this point to then? Could a low battery possibly cause these voltage issues I'm having? Or is this something more?.... Should I try to drive around with the neg disconnected n see what voltages I see? I only did it parked..