Alternator not charging at idle

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Kevin88RRC

Well-known member
pmatusov

pmatusov

Technical Excellence Contributor
Callsign: AK6PM
vintagepatina said:
I've installed several of these GM CS130 alternators on Rover V8s, 200Tdis, 2.25s in place of the Lucas. Nothing special about the BP Utah one aside from they have rotated the front case to fit.
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I am curious... Is there any advantage in using a CS130 vs. late-Classic/D1/P38A/D2 alternators?

I could, in theory, buy the argument of COTS availability, but I have four or five Marelli alternators in my garage. BPUtah and others sell the voltage regulator/brush unit for those, and it takes very little time to replace is (and maybe the front bearing as well). A spare alternator takes up space in my spares Pelican on my trips, but I'd rather ditch it for a spare regulator and maybe a diode pack.
 
Robert

Robert

Well-known member
pmatusov said:
I am curious... Is there any advantage in using a CS130 vs. late-Classic/D1/P38A/D2 alternators?

I could, in theory, buy the argument of COTS availability, but I have four or five Marelli alternators in my garage. BPUtah and others sell the voltage regulator/brush unit for those, and it takes very little time to replace is (and maybe the front bearing as well). A spare alternator takes up space in my spares Pelican on my trips, but I'd rather ditch it for a spare regulator and maybe a diode pack.
Click to expand...


If you're going to kludge a non factory alternator in there at least go with the AD 230 or 244 style. Their low RPM output is much better than the CS alternators.
 
V

vintagepatina

Well-known member
there is no kludging. it bolts in. i buy them in the 105A variety brand new for about 55 bucks shipped. great for a series 3 or 200tdi.
 
Robert

Robert

Well-known member
vintagepatina said:
there is no kludging. it bolts in. i buy them in the 105A variety brand new for about 55 bucks shipped. great for a series 3 or 200tdi.
Click to expand...


was referring to the question regarding the marelli alternators, since they have a unique case footprint nothing bolts in place.


You still may want to look at the RPM vs max current chart for that alt and see if you want to stick with the older style.
 
pmatusov

pmatusov

Technical Excellence Contributor
Callsign: AK6PM
Robert said:
If you're going to kludge a non factory alternator in there at least go with the AD 230 or 244 style. Their low RPM output is much better than the CS alternators.
Click to expand...

I wasn't going to, my question was about the reasons to do it at all. I guess 55 bucks is a good enough reason, especially for old or ROW trucks.
 
K

Kevin88RRC

Well-known member
After all this troubleshooting I finally got a part number to test it against...... both diode & regulator FAILED. BpUtah is shipping a replacement today with a return label for the failed one.

Need to have her up & running before next Thursday... she's booked for her second photo shoot. It will cover the new alt & all the beer used during troubleshooting. :D
 
K

Kevin88RRC

Well-known member
I also think I'll take the opportunity to finally install the battery connectors from Tiktaalik and new cables... only been a few years on the shelf. Someone posted a link to a site that make custom cables. Does anyone know which I'm asking about? Can't find my bookmark.

Or I can go down to the local marine store & make some. Would just prefer someone who knows what they are doing to make them.
 
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O2batsea

Well-known member
Genuinedealz.com makes the battery cables from marine grade wire.
But Matt is right, it's stupid easy to make your own. In a pinch you can use a drift punch to crimp the terminal to the cable. Do it on concrete so when you hit it, it's a solid whack.
 
V

vintagepatina

Well-known member
what part number did you use?

also with regards to battery cables, i solder all of mine. put the cable lug in the vise with cable end upwards, heat with butane torch, melt solder into lug end making a little cauldron of melted solder, keep the torch on it, insert stripped cable end fully, done. heat shrink
 
K

Kevin88RRC

Well-known member
Napalm00 said:
It's a monkeys job really . The hammer crimper is $20 on Amazon
Click to expand...

I got a visual. lol :D

Thanks for the link.... that's the one I was thinking of. I will do a cost & time comparison. What gauge do y'all recommend? I'll be using the battery connectors by OJOP.

We used part #N111795B for a 95 Suburban.
 
O

O2batsea

Well-known member
Solder unnecessary if crimp is good. Crimp + solder OK. Solder only no. Battery cables routinely heat beyond the melting point of solder = fail.
I also recommend the Mil-spec adhesive lined shrink for the battery cables. As for size...depends. For normal starting circuit you can get away with 2 AWG, but that's kinda small. I like 0 or even 00 AWG for both hot and ground side of battery.If you are running cables to a winch you want them fat; def 00 AWG.
 
rocky

rocky

NAS-ROW Addict
Tracked my Voltage this morning. All it needs to do it get a little above idle to start putting volts back into the battery. After that, even if it drops to idle, the voltage stays up.
 
Napalm00

Napalm00

Technical Excellence Contributor
I use 00 for winch
2awg for battery to starter and 4awg for alt to starter


Keep in mind on 45 amp diesel trucks dual 12 AWG wires were the primary charging circuit . TINY! like speaker cable
 
K

Kevin88RRC

Well-known member
So the saga continued through the weekend.

New alternator arrived Saturday afternoon. I install it Sunday morning and similar results not charging at idle but did start charging sooner. Tried my best to tight the steering pump belt in case that was the cause & that belt is such a PITA to tighten. Nope not that. :mad:

Pulled alt back out & brought it to get tested this morning thinking it too is bad. Nope... passes the tests with flying colors.

Removed pulley & replaced with original. Of course it sits set back farther the new shiny beefy pulley. Luckily the spacers off the the VW Bosch alt work perfectly and luckily i bought a shorter belt because now the adjustment bracket hits alt. So i have to drill a new mounting hole at water pump side to make work.

Long story short.... she's now charging at idle! .....finally :rolleyes:

This should have been a straight drop in. Maybe original length belt works with the newer alt bracket with the tensioner. Will try to source one. Can someone who has one measure the length please.
 
K

Kevin88RRC

Well-known member
Spoke too soon.
First test idle was around 13.5 but very jumpy. Put some stuff back together in engine bay (fan & shroud) now it's back to not charging. Belt is tight. Starts charging quickly.

What am I missing? Could the fan load really keep it from spinning fast enough to start charging?

Will probably pull & return but need to find another replacement.

ggrrrrrrrrrrrr
 
Napalm00

Napalm00

Technical Excellence Contributor
I don't think it's your alternator you have a voltage drop somewhere else in the system.

I would check resistance to ground on both sides of the fuse for each individual circuit in your truck.

I'd also pull each fuse one by one when the truck is charging and see if it changes the voltage output of the alternator measured at the battery.
 
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