voltage regulator

[T1 woodywagon]

Can someone explain to me how the voltage is regulated in my charging system.The car is my 87' T1 wagon.

[BadAssPerformance]

Pretty sire voltage is regulated inside the Power Module (the computer next to the battery)

[tryingbe]

Are you experiencing low or high voltage?

[T1 woodywagon]

I removed my oem computer and installed a custom lm,I started the car and it showed all the bars on my digital dash meter,so I tested with my digital volt meter and it was charging 17.30 volts.I shut off the car and re-installed the oem computer and it was back to 14.1 volts.

[turbovanman²]

I removed my oem computer and installed a custom lm,I started the car and it showed all the bars on my digital dash meter,so I tested with my digital volt meter and it was charging 17.30 volts.I shut off the car and re-installed the oem computer and it was back to 14.1 volts.

That's weird, the PM at the battery controls battery charging.

[ShelGame]

No, the LM actually controls it. The PM just has the high power drivers in it. There's either something wrong with the LM itself, or - more likely - something wrong in the cal. I'm looking into it.

[T1 woodywagon]

sounds good rob.

[turbovanman²]

No, the LM actually controls it. The PM just has the high power drivers in it. There's either something wrong with the LM itself, or - more likely - something wrong in the cal. I'm looking into it.

Oh, learned something new, thanks.

[BadAssPerformance]

Oh, learned something new, thanks.

Ditto. And this sounds somewhat familiar as I have heard cars with charging issues due to corroded LM connectors.

[ShelGame]

I didn't get the chance to check this out while on vacation, but I will look at it this weekend.

[ShelGame]

I e-mailled this to Shawn directly, but thought I'd post it here for refernce as well...

I don’t see anything in the cal that would cause that. I had at one point added a WOT Battery volts target. But, I removed due to a problem. I checked to make sure it was actually removed from the cal that I built for you (it is removed). So, the voltage regulator code is all stock.

The ambient temp sensor is in the Power Module. Since you swapped only the LM, I think we can assume that the PM and the Amb Sensor is OK.

The problem could only be in the LM hardware some where. Maybe the voltage reg output pin isn’t making good contact? That’s pin 5 on the red connector.

I guess it could also be the air temp pin not making good contact. That’s pin 20 on the blue connector. Though, if that signal was bad, you should get the default charging voltage of 14.25V. You said you’re getting 17+ right? The ECU can’t even set the target higher than ~16V.

I really think the problem must be in the LM connector. Maybe check pin 5 red for corrosion.