Alternator slow to start charging

[Erik the Awful]

However the alternator didn’t start charging right away. It was as of the alternator wasn’t doing anything, verified by 11.2 volts at the battery.

After about 20 minutes it started charging like normal, and was fine on the drive after that.

I'm not familiar with the circuit or how it develops the field. Coming from a background in maintaining generators, it sounds like it's supposed to get battery voltage to flash the field and start generation.

If the battery voltage was weak, it may have struggled to flash the field. Or it may not be flashing the field at all and it took a while for the field to build up enough strength to begin generating. I've also heard of alternators that don't generate until you get them above a certain rpm.

You might try checking the voltage on startup and then seeing if you can get it to start generating by blipping the throttle to 3000+ rpm.

If it is a CS130 or CS144 as listed above, I'd jump straight to throwing a new voltage regulator on it. The diagram @1990Z71Swede posted clearly shows the voltage regulator controlling the field.

 

[Reluctanse]

There’s no charge light on the dash, just the low gauge. It did the same thing even after I put the battery on a charger and got back up to full. It’s 4 years old at this point, but I don’t think it’s the issue.

Yeah it’s a CS144. Voltage regulator makes sense. I’ll give the wiring a good once over before I order one but they just seems likely to me.

Thanks-

 

[AuroraGirl]

There’s no charge light on the dash, just the low gauge. It did the same thing even after I put the battery on a charger and got back up to full. It’s 4 years old at this point, but I don’t think it’s the issue.

Yeah it’s a CS144. Voltage regulator makes sense. I’ll give the wiring a good once over before I order one but they just seems likely to me.

Thanks-

show me a picture of your gauge cluster

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if you DO NOT get a charge light on at key on, i found your issue, youre not exciting your alternator. To excite your alternator you need to provide resisted 12 volts to the L terminal on the alternator 4 wire plug (they are labled on the alternator or the plug or both) You resist it by using a 194 bulb so not to provide full 12v, (that is bad for the regulator) If you instantly start charging by doing this, your issue is 100% the light being gone

 

[jd33173]

1st question i would ask is how old the battery is. get it to the autoparts place and have them LOAD TEST the battery. chances are good battery is fragged and the cold did not help it at all. There is no such thing as a 60 i mean 48, i mean 36 month battery in miami temperatures (high and low) play a big role. If there have been little to no shenanigans with wiring, etc, I would say its the battery not allowing the alternator to get going.

 

[GoToGuy]

So as the previous post said, and as the diagram shows , there is a " GEN " light on your Inst panel. When you insert key turn to " ON " or " RUN " position, not start. The Inst lights cycle through a bulb test. Do you get a " gen " light ? You should. The owners handbook shows all dash lights and description. Or the OE service manual.
The gen light circuit is shown on this diagram , it's number 33.

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[GoToGuy]

Correction #25, BRN , brown wire.

 

[bluex]

Yeah it’s a CS144. Voltage regulator makes sense. I’ll give the wiring a good once over before I order one but they just seems likely to me.

Thanks-

If you replace it, do yourself a favor an put an AD244 on it from an 03 or so suburban with the 140a option.

 

[termite]

If you replace it, do yourself a favor an put an AD244 on it from an 03 or so suburban with the 140a option.

What's required to swap in the ad244?

 

[HotWheelsBurban]

If you replace it, do yourself a favor an put an AD244 on it from an 03 or so suburban with the 140a option.

Is that the same alternator the later OBS Burbs use? It's 145 amp, and I think all you need for that swap is the longer belt(besides the alternator of course).

 

[FullBlowncustoms]

ADD grounds !!! Unless battery has dead cell area.... My old K1500 bomber put new alt, new battery, still low on gauge, added new grounds, and she came to life !! maybe not your situation but cured my winter bomber.