911/914-6 regulator wiring ugh Options

[SirAndy]

Not sure if this may be related (since my engine is completely different) but i have to rev up the engine to above 4k ish rpm once to get the alternator to kick in and produce enough current to charge the battery.

If i just turn on the car and let it idle, it never gets that initial kick and just sits at 12V.
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[mb911]

Not sure if this may be related (since my engine is completely different) but i have to rev up the engine to above 4k ish rpm once to get the alternator to kick in and produce enough current to charge the battery.

If i just turn on the car and let it idle, it never gets that initial kick and just sits at 12V.
(IMG:style_emoticons/default/idea.gif)

Andy very possibly. So I just corrected a gauge issue but while doing that I tested the D+ lead vs the battery and there is a 1 volt drop between the 2. Hmm bad connection maybe? I will have to look around for that but so odd. Could that be the bulb itself with that much resistance?

[ClayPerrine]

Not sure if this may be related (since my engine is completely different) but i have to rev up the engine to above 4k ish rpm once to get the alternator to kick in and produce enough current to charge the battery.

If i just turn on the car and let it idle, it never gets that initial kick and just sits at 12V.
(IMG:style_emoticons/default/idea.gif)

That is a common problem with a 964/993 that has been converted to a single belt. The factory had the alternator spinning at a faster speed than the fan. A conversion to a single belt causes it to spin too slow at idle to get the alternator to start working. I had to tap the accelerator to get the alternator to kick in every time.

[mb911]

Minor update. Ohmed out the blue D+ wire back to the gauge. No measurable loss. The red/white switch 12v adjacent to that wire reads 1v less than the battery. I need to check that out next

[Superhawk996]

Minor update. Ohmed out the blue D+ wire back to the gauge. No measurable loss. The red/white switch 12v adjacent to that wire reads 1v less than the battery. I need to check that out next

Sounds like you are on the right track

[mb911]

@superhawk996 so interesting enough with no fuel pump running there is no voltage loss. Gonna change out the ignition switch to be sure might need a relay on the pump

[Superhawk996]

@superhawk996 so interesting enough with no fuel pump running there is no voltage loss. Gonna change out the ignition switch to be sure might need a relay on the pump

Good find

I can’t remember how much current fuel pump draws but should only be a couple amps - let’s say 5 amps? To get 1v of voltage drop across wiring would mean you have wiring with 0.2 ohms of resistance in it.

Agree ignition switch is a good 1st place to look but if it’s not there, you’ll need to track it back to wherever it resides. Worst case is that it’s a few smaller drops across wiring, terminal connections etc.

Is your fuel pump re-wired or are you running it off the relay board and OEM round relay back in engine compartment. Can’t remember what you did for the /6 conversion.

[mb911]

@superhawk996 so interesting enough with no fuel pump running there is no voltage loss. Gonna change out the ignition switch to be sure might need a relay on the pump

Good find

I can’t remember how much current fuel pump draws but should only be a couple amps - let’s say 5 amps? To get 1v of voltage drop across wiring would mean you have wiring with 0.2 ohms of resistance in it.

Agree ignition switch is a good 1st place to look but if it’s not there, you’ll need to track it back to wherever it resides. Worst case is that it’s a few smaller drops across wiring, terminal connections etc.

Is your fuel pump re-wired or are you running it off the relay board and OEM round relay back in engine compartment. Can’t remember what you did for the /6 conversion.

I am not using a relay at all so just switched 12v but with switching to the 044 pump it maybe necessary now

[Superhawk996]

@superhawk996 so interesting enough with no fuel pump running there is no voltage loss. Gonna change out the ignition switch to be sure might need a relay on the pump

Good find

I can’t remember how much current fuel pump draws but should only be a couple amps - let’s say 5 amps? To get 1v of voltage drop across wiring would mean you have wiring with 0.2 ohms of resistance in it.

Agree ignition switch is a good 1st place to look but if it’s not there, you’ll need to track it back to wherever it resides. Worst case is that it’s a few smaller drops across wiring, terminal connections etc.

Is your fuel pump re-wired or are you running it off the relay board and OEM round relay back in engine compartment. Can’t remember what you did for the /6 conversion.

I am not using a relay at all so just switched 12v but with switching to the 044 pump it maybe necessary now

Got it.

Yeah would definitely want that “battery” side of the D+ feed circuit to be reflecting full battery voltage over at the Gen light bulb (yellow highlighted wiring)

[mb911]

@superhawk996 so interesting enough with no fuel pump running there is no voltage loss. Gonna change out the ignition switch to be sure might need a relay on the pump

Good find

I can’t remember how much current fuel pump draws but should only be a couple amps - let’s say 5 amps? To get 1v of voltage drop across wiring would mean you have wiring with 0.2 ohms of resistance in it.

Agree ignition switch is a good 1st place to look but if it’s not there, you’ll need to track it back to wherever it resides. Worst case is that it’s a few smaller drops across wiring, terminal connections etc.

Is your fuel pump re-wired or are you running it off the relay board and OEM round relay back in engine compartment. Can’t remember what you did for the /6 conversion.

I am not using a relay at all so just switched 12v but with switching to the 044 pump it maybe necessary now

Got it.

Yeah would definitely want that “battery” side of the D+ feed circuit to be reflecting full battery voltage over at the Gen light bulb.

Yup so that is my plan. Just wish this 90% humidity and 90 plus degrees would go away for a few days to get this solved

[Superhawk996]

One quick thing to do: rotate fuse 9 and see if the voltage drop goes away.

I absolutely don’t miss Midwest heat & especially the humidity. I know how miserable it is.

[mb911]

One quick thing to do: rotate fuse 9 and see if the voltage drop goes away.

I absolutely don’t miss Midwest heat & especially the humidity. I know how miserable it is.

Sounds good will try that as well. Midway through the 911 ignition switch replacement. Heading to lake now for some boating and cooling down

[mb911]

Ok switch is changed out, checked and replaced any questionable grounds, ran a fuel pump relay(fused) along with the inertia switch, cleaned up the connections on the fuse panel and now all is well. What’s amazing is that I cleaned it a year or 2 ago. Thanks for all the help everyone