Cs144 Alternator Questions

https://www.bluesea.com/support/articles/Circuit_Protection/1441/Part_2%3A_Select_a_Fuse_and_Fuse_Holder_For_Your_DC_Product_Installation

Short run from alternator to fuse box, etc, plus you want to over wire, under fuse is my understanding

 

My latest spacer, hair under half an inch. Long story for another day.

 

Alright, so I got it all going.

is anyone watching voltages in cab while driving?

700 idle rpm (~1600 alternator rpm) voltages are fine

500 in gear idle (~1200 alternator RPM) voltages drop through the floor. Way worse than stock Denso with an electric fan and AC.

so I spoke to a expert that says GM specs these things for ~1800-2000 rpm at idle. Said that even 1500rpm is too slow. This correlates the the 80-100 amps people always refer to when talking about cs144s

I’ve ordered a 2” pulley but at 500rpm in gear rpm it’s still under 1500rpm alternator.

This all makes sense when you look at charts.

I guess this isn’t a hugely popular mod but Its just kind strange this hasn’t been mentioned.


EDIT: I guess it’s also worth mentioning that my pulley on the alternator is at least 2.44” in dia. I believe that’s what I have but I haven’t measured it. I think whatever pulley mechanicjohn is running is even larger than that.

 

I watch my voltage. It’s at 14.2ish at idle and 14.7 while driving

 

What are you using to measure voltages in cab?

I have seen differences/discrepancies between measuring devices. Do you have a dual battery setup?

 

Just a single battery.

The thing is, the only real reason I did this was because I added an electric fan (just can’t stop fucking with things) and started watching voltages on my UltraGauge. With the Denso I was seeing drops to lower 13s. With the summer heat coming I went ahead and took it to a alternator shop for advise ant they hooked everything up to a portable rig for testing.

At idle with everything going full tilt I was drawing 85 amps. So I figured I’d burn the little Denso up if I didn’t do anything.

now my voltages drop like a rock below 700rpm. Like it’s showing 12.7 and below. the Denso did way better even though I was drawing more than its rated for just sitting at idle. When I say drop off like 700rpm it’s 14v and 650rpm it’s 12.7v.

it’s worth mentioning the denso has a 2.1” pulley and the CS144 has a 2.44” pulley. Ive ordered a pulley to get the RPMs back up. From what I understand it needs to be running near 1800rpm for charging.

but I am quite confused as to why I seem to have this issue with the same setup other people are running.

Add to the fact that speaking with some alternator guys they all pretty much said it needs 18000 at the very least to output. This is despite the fact that I can’t seem to find any reputable source that states that as a fact. So yeah, don’t know what to think.

 

@Shortman5
14.7V at 750RPM, that's cold with fully charged battery less the discharge from one start. Really cold it can hit 15V for a few mins. Trickles down to around 14.2V as battery charge is restored and things warm up. No drop at idle from headlights, fan etc.

Alternator is a "new" Delco #335-1048, made in Mexico for and sold by Delco. Has 56mm pulley measured at "tips" of the grooves.
Kind of tough to measure the crank pulley with the belts on but I make it out to 150mm for a ratio of 2.68 alt to crank. That equates to 2010 alt rpm at 750 engine (man trans).

Handy available pulley source (17mm bore)
https://store.alternatorparts.com/17mm.aspx

 

Yeah, 12.7VDC at less than 700 RPMs is not normal. Something isn't right.

 

I’m getting around ~14+ at park/ neutral 700 idle. It’s when I’m in gear at idle and idle drops to to 600 +/- that it stops charging.

Considering I have an auto and I can’t find anything to support that anything less than 1800rpm at idle is sufficient for charging on a CS144 I’m thinking it’s playing a role.

Also, I could have also sworn that I’ve seen lower rpm in gear idle in the summer months before. Maybe I’m just misremembering though.

I ended up wiring the sense wire back into the OEM harness. Im now only bypassing the fuse box with a 4ga wire directly through a breaker then to the battery. Instead of the sense wire being wired directly in line with the charging wire. Seems to have helped some but I not convinced that’s going to solve it.

Im still wondering if having the factory wiring all hooked up is important for the regulator operating property for a low EFI rpm application. Ive read some material that’s seems to support the fact that sense directly to the charging wire only allows the regulator to operate based on RPM. It Depends on who you ask. Seems like the only sources of information that support the 1wire vs 2 wire being no different are also selling alternators.

Crank is 5.9” and the pulley on my CS144 is 2.44”. So 1450rpm in gear at idle.

stock pulley on the 80A Denso is 2.1 so That’s 1675rpm in gear at idle.

So I’m going to try a smaller pulley to get close to the recommendation of 3:1

 

Well,

I got it figured out. It was the alternator pulley. With a 2” pulley I’m getting just over 14v in gear and at idle with no AC.

With a automatic idle drops to the mid 500s while in gear without the AC clutch on.

 

I'm a T4R.org member that stumbled across this thread while having the exact same issues. Did the CS144 mod this summer after my OG alt crapped out right around 200k miles. All seemed well until the outdoor temps here in Chicago started dropping recently. Was monitoring the voltage and noticed the same exact thing. I got mine from DB Electrical and that too came with a 62mm (2.44") pulley. I'm planning to order a 53mm pulley from Metro Auto Inc (http://www.metroautoinc.com/new/ind...63_66_68&product_id=1120&filter=1349,951,1026) to resolve the issue. See attached test report from the alt that I have. Also attached a couple pics of the numbers while warming up the rig this morning in 20 degF.

Thanks again for the info in this thread...great stuff!!!

 

I'll add my update referencing posts 42, 5, 12, and 20.
https://www.tacomaworld.com/threads/cs144-alternator.795316/#post-28494173