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Old Yesterday, 12:12 PM   #26
vardenafil
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Re: Need help with alternator

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here is the back where the wires normally connect.

Last edited by vardenafil; Yesterday at 12:35 PM.
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Old Yesterday, 12:37 PM   #27
vardenafil
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Re: Need help with alternator

would the best fix be tossing the current alternator and getting a SI and wiring it like this?

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Old Yesterday, 03:09 PM   #28
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Re: Need help with alternator

I have to agree with RustyPile that something is going on with the engine placement preventing the fan from lining up. Not that uncommon with K models as many that left the factory with I-6's and got converted to V8 's along the way. Judging from the your valve cover only I'm guessing the truck no long has the original engine.

If you want to correct the misalignment of the fan and shroud we will need more photos of the motor stands, the clearance between the firewall and the distributor, the transmission crossmember, the core support and radiator mounts.

I also understand you just wanting to get the truck running. Are you planning on using the truck as a daily driver? If so what summer time temperatures do you expect to be driving in? Would you expect to experience stop and go traffic? Knowing the answers to these questions will help us guide you to the right electric fan conversion for your needs.

There are hundreds of millions of vehicles with electric cooling fans on the road right now and they all were engineered to match the vehicle and its intended use. If you want the same success you need to do the engineering too. You also need to use quality components like the OE's do. They build and sell vehicles expecting them to see 115 degree weather and not overheat in stop and go traffic, for the life of the vehicle's warranty.

Avoid cheap parts as they were only designed to make you part with your money.

Your 10 volts at idle is common on many vehicles of this era. They were not engineered with stop and go traffic in mind. The rpm of the alternator at idle isn't enough to make the alternator charge by design.

No matter which path you chose to go doing the homework now will make for trouble free driving down the road. So trouble free you won't remember the work it took to get there.

Good luck and keep us posted.
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Old Yesterday, 03:18 PM   #29
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Re: Need help with alternator

Quote:
Originally Posted by vardenafil View Post
would the best fix be tossing the current alternator and getting a SI and wiring it like this?

Attachment 2384959
Installing a 12SI is a good way to go. Is that one of VetteVet's schematics? If so you can count on it being correct. Going from your description you should take the time to inspect and verify your existing wiring is usable and still connected to the proper places.
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RIP Bob Parks.
1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo
If it breaks I didn't want it in the first place
The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377
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Old Yesterday, 05:00 PM   #30
MARKDTN
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Re: Need help with alternator

The 10SI and 12SI alternators really don't like high amp versions. They are out there on Pontiacs and police cars, but they really are not as good as an upgrade. I would upgrade to a CS144 alternator and change to a voltmeter if you have an ammeter. Application 1996 Caprice or Roadmaster. You will have to change the pulley to a V-belt style. There are replies about the original electrical system not being able to handle fans and that is true. Any high output alternator will require bypassing the ammeter anyway. I would run a large wire (~8ga) from alternator to battery hot post and run all fan wiring also from the hot post on the battery. Use a relay to ignition power to turn off power to the fan if you don't want it running with ignition off. That way the original electrical system is left alone (besides the ammeter if applicable). If a single speed fan you can put a temperature switch in the head that provides a ground for the relay. If you want a 2-speed fan look into a Volvo relay/BMW temperature switch and you can do that too. Good luck with it.

IMHO the CS130 is not good for a paperweight so go ahead and get a CS144. The wiring is the same either way.
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Old Yesterday, 07:42 PM   #31
RichardJ
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Re: Need help with alternator

>> I would run a large wire (~8ga) from alternator to battery hot post.<<

Part of Mad Electrical discussion about increasing the size of the charging wire.

THE BATTERY CHARGING WIRE (Please refer to “The ORIGINAL CHEVY SYSTEM” diagram.)
In the case of voltage drop at the long “battery charging wire,” the small amount of voltage drop was actually a good thing. In honest retrospect view of the long battery charging wire, the beneficial side effect caused by the long wire was probably not intentional. More likely it resulted from location of the parts. The battery tray was on the passenger side. The driver’s side had the alternator, voltage regulator and dash power hook-up at the Horn Relay. The battery charging wire connected the battery at the right to the rest of the system at the left. Knowing that the battery would eventually become charged and significant voltage drop would then disappear, it’s likely that the engineering department simply allowed it to happen.

Current flow through the battery charging wire will only be a large amount when the battery is discharged. Therefore, significant voltage drop only occurred when recharging a low battery. This is when the beneficial side effect comes into play; the voltage drop in the battery charging wire slowed the battery charge rate. Slow rate battery charging is less abusive to the battery than a fast charge rate. Slowing the charge rate a little can also reduce the probability of alternator overheating damage when recharging a low battery while driving. And slow charge rate reduces corrosion at the battery area of these good-looking Hot Rods!

The battery stops accepting much current as it becomes fully charged, and as current flow tapers off then voltage drop is reduced. Therefore a small amount of resistance at the long battery charging wire does not prevent the battery from becoming fully charged—it just takes a little longer to recharge a “low” battery.


Basically, increasing the charge rate with an oversize wire has some side effects you may not want.

My '67 has 2 fans, HEI, Electronic Climate Control AC, electric trailer brake controller and it still has the 10DN alt.
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Old Today, 11:08 AM   #32
MARKDTN
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Re: Need help with alternator

I was more concerned with making the original wire too hot and melting the insulation. If you have a 160A alternator where a 37A used to be and you add dual fans that pull 15-20A each running you may be in for problems. A 10Ga wire 4-7 feet is recommended for a max 65A while an 8ga is OK for 125A. I suppose 10ga is OK but seems marginal to me with dual fans-especially if it is 50+ years old. On my '83 K20 I added dual C4 Corvette fans and upgraded to a CS144. I ran an 8ga to the battery in addition to the stock wire and have had zero issues in almost 20 years. It already had a voltmeter.
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Old Today, 12:40 PM   #33
vardenafil
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Re: Need help with alternator

Quote:
Originally Posted by HO455 View Post

If you want to correct the misalignment of the fan and shroud we will need more photos of the motor stands, the clearance between the firewall and the distributor, the transmission crossmember, the core support and radiator mounts.
here are some pictures and measurements. from the distributor to the fire wall there is about 3 inches max. from the water pump to the radiator there is 7 1/2 inches.

the radiator core support rubber is all new. the radiator support brackets and rubber is also all new.

I think the truck originally came with a v8. on the core support it has a sticker that says 350 v8. i am not sure if the core support is original to the truck or if the v8 in the truck is original or a replacement. the tranny however is a different story. the truck originally had a manual tranny. the PO converted it to an automatic. so i think this is where the misalignment is? here are pictures of the motor mounts and tranny mounts.i noticed that the front cross member is bolted in the middle bolt holes. im not too sure where they are supposed to be bolted at. i just ordered poly motor mounts and a small spacer to see if i can get a little more lift on the block. thanks for looking at my pictures and helping me figure out this mess.

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Old Today, 02:26 PM   #34
54blackhornet
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Re: Need help with alternator

Quote:
Originally Posted by HO455 View Post
I have to agree with RustyPile that something is going on with the engine placement preventing the fan from lining up. Not that uncommon with K models as many that left the factory with I-6's and got converted to V8 's along the way. Judging from the your valve cover only I'm guessing the truck no long has the original engine.

If you want to correct the misalignment of the fan and shroud we will need more photos of the motor stands, the clearance between the firewall and the distributor, the transmission crossmember, the core support and radiator mounts.

I also understand you just wanting to get the truck running. Are you planning on using the truck as a daily driver? If so what summer time temperatures do you expect to be driving in? Would you expect to experience stop and go traffic? Knowing the answers to these questions will help us guide you to the right electric fan conversion for your needs.

There are hundreds of millions of vehicles with electric cooling fans on the road right now and they all were engineered to match the vehicle and its intended use. If you want the same success you need to do the engineering too. You also need to use quality components like the OE's do. They build and sell vehicles expecting them to see 115 degree weather and not overheat in stop and go traffic, for the life of the vehicle's warranty.

Avoid cheap parts as they were only designed to make you part with your money.

Your 10 volts at idle is common on many vehicles of this era. They were not engineered with stop and go traffic in mind. The rpm of the alternator at idle isn't enough to make the alternator charge by design.

No matter which path you chose to go doing the homework now will make for trouble free driving down the road. So trouble free you won't remember the work it took to get there.

Good luck and keep us posted.
Excellent ! Great suggestion.
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Old Today, 05:17 PM   #35
70STOVEBOLT
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Re: Need help with alternator

Are the last two pics the engine crossmember or the trans crossmember?
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