Will's'74VetteL-82

Hello everyone!

I has been a few *years* since I last posted/lurked, but my car is slowly coming together. Hurst shifter, new body mounts, and now a new Dewitt's radiator and dual SPAL fans. Car is a '74 4 speed.

I checked high and low on the forum and the internet, and as usual I cannot find one concise answer on how to upgrade my alternator to a CS144.

The three questions I have are - which model alternator is the correct one, which adapter harness is needed (our cars have an ammeter, does this supply the correct resistance?) and what is the best way to upgrade the wiring for the output?

My fans currently work and are wired to an adapter post on the battery. I do not want to run the car on the factory wiring for long though.

Please let me know what you think. Some people say wire right to the battery, some say a wire from the output to the solenoid is fine, fuse vs fusible link. I will post pictures once the project is done

Thanks,
Will

Alwyn678

Any ideas?

lionelhutz

There is no concise answer. It can be done many different ways.

You need an adapter with a resistor or just add a resistor into the wiring.

I believe the alternator from a mid 90's B-body or F-body would work fine.

I would put a new wire from the alternator to a terminal block and then from the terminal block to the solenoid. 6 gauge wire would be appropriate. Put a fusible link at the solenoid.

Run the fans from the new terminal block.

The alternator has a voltage sensing terminal. I would connect it to the new terminal block.

I believe your car has a horn relay used as a junction block. Remove the old wire that ran from the alternator to the horn relay and the wire from the horn relay to the solenoid. Put a wire from the new terminal block to the horn relay.

The issue is that the ammeter no longer works when you do this. The easiest fix is to change it to a voltmeter.

If you don't want to change to a voltmeter then you need to reconfigure the ammeter wiring to somewhat measure the charging/discharging current. You can do this by putting the horn relay wire to the new terminal block and the other wire to the solenoid. The ammeter won't measure the same as before, but it will show something.

Will's'74VetteL-82

Wow, *this* is the concise answer I was looking for! This is surely sticky worthy.... I was concerned about adding the additional wiring and creating a loop where the upgraded wire still left the system in a dangerous manner. Your method clears that up

Keeping the ammeter would be cool, even if it doesn't read correctly (I suppose it wouldn't account for the draw of the fans). When I redo the interior I will then convert it to a voltmeter.

Thank you so much! I will post back on the progress...

-Will

Will's'74VetteL-82

Just ordered the CS144 alternator, adapter harness with resistor, 6 gauge wire, 10 gauge fusible link, and a 250 amp buss bar. I will get the crimp terminals locally. Should be a good install.

-Will

Tampa Jerry

I would think about adding a relay for each fan. You can get a wealth of information as well as an inexpensive relay kit with wiring from Mad Electronics. Mark is the man for this stuff. Google his site. Jerry

lionelhutz

I didn't mention it but I would first recommend a PWM fan controller.

If you don't want to spend the money, then use 3 relays and wire the fans in a 2-speed configuration.

Will's'74VetteL-82

Fans are already relayed via the SPAL kit. The load from the fans in a single speed mode really isn't an issue, I drove the car all day yesterday no problem. I just don't want to burn my car down in the long run...I will also be doing EFI in the future so an upgraded charging system is definitely required.

-Will

pws69

Are you referring to "MAD Electrical"?
i.e. http://www.madelectrical.com/catalog/rly-1.shtml

Will's'74VetteL-82

I like what I see there...gets the gears going for doing the headlight relay setup haha

-Will

Will's'74VetteL-82

Good news! I have the alternator and wiring up and running. Here is how it went down:

Installed CS144 from 1995 Impala SS. Installed with no modifications at all.
Adapter harness with resistor was installed to adapt to factory harness.
Ran 6ga wire from alternator output to 250A terminal block, then ran wire with 10ga fusible link to solenoid.
Electric fans ran straight to terminal block instead of battery.

The factory wiring I kept wired as per original. 1974 was the first year for the horn relay design to be changed from the terminal style to just a connector. There wasn't really the option of running new wires without hacking the harness.

The factory wiring should be fine now, because there is no additional load on it - because the fans are routed to the terminal block, the load is zero. Even the ammeter reads no load when the fans are on, as opposed to before where the ammeter read 40+ amps when the fans turned on. I think that indicates that the project was a success.

The only issue I have is the CS144 plastic fan seems to be warped when you torque the v belt pulley onto it, so it rubs the case a little bit. I don't know if I should add some washers to lessen the force on the fan from the pulley. What do you guys think? No one else online seemed to indicate doing so....

I also installed a 180* thermostat so the fans cycle perfectly now, just like a modern car. Before they ran constantly because both thermostats were set to 195*.

Thanks again for all of the help, the project went smoothly because of it!

-Will

lionelhutz

Was there a spacer sleeve between the fan and the pulley? You may need a spacer or more spacers in there. The pulley should compress on the center of the fan, not the outside.

hugie82

https://www.dbelectrical.com/alterna...ive/chevrolet/
Helped me out. Great customer service too!

Will's'74VetteL-82

The original CS144 serpentine pulley had a built in spacer so the majority of the compression force was on the center of the fan. I suppose I could just throw some washer in behind the v belt pulley to space it, however, washers are certainly not the king of concentricity...

Any thoughts?

-Will

Will's'74VetteL-82

I'll give them a call....I see you are in Bridgewater, nice to see there are some people close by!

-Will

Will's'74VetteL-82

Problem Solved! The old 10SI did have a spacer that I neglected to install on the CS144. 5 minute job to swap that in and the fan is perfect now. Job is complete at this point. Now the car just needs the EFI swap...

-Will

Pmccooey

Great post!!! Looking to do this upgrade in the future when putting my 69 back together since I'll be running dual fans and EFI.

Will's'74VetteL-82

Sounds good! With the help of the great people on this forum, the job was a breeze. The electric fans and new alternator change the whole car. Make sure if your electric fans come with a 195* thermostat you change to a 180* thermostat in the engine. It then cycles like a modern car and maintains temperature perfectly.

You have a 69 so your horn relay is the old design, so you should be able to follow lionelhutz's instructions to the letter.

I will post up some pictures tomorrow that should help.

-Will

lionelhutz

It's been a while since I've had a pulley off a 10SI, but I recall a spacer in there, just couldn't recall if it was behind the fan or between the fan and pulley.

NewbVetteGuy

You guys, this thread is awesome and gives me the last little confidence boost that I need. As soon as I finish up my HID / LED halo headlight install this weekend I'll be making almost identical purchases.

Will: Were you able to use the stock driver's side alternator bracket with the CS144? -This was the last item in the swap that I couldn't figure out. Some people have reported that the stock brackets don't work or that you need to drill some new holes.

Thanks!

Adam