Pulsating voltage to the blower unit?

[smitty]

EDIT: Seems I have got it wrong, it is actually the fuel pump noise that is pulsating with the indicator. See here.

Since I got my car back, I have noticed that whenever I indicate left or right, with each pulse of the indicator, the air con fan slows momentarily. So with each "on/off/on/off" with the indicator relay, the fan is going "slower/faster/slower/faster".

I suspect this would also be related to the recent issues i've had with my Ac control unit: air vent controls dont seem to do anything, and the fan seems to blast harder than it used to. (too much power maybe, caused it to shit itself?)

While it was off the road, I also installed positive(ignition) and earth bus bars, for EBC, boost gauge and exhaust control. The ignition bus bar is powered from some 8 gauge I ran from the battery, through a relay, which uses the ignition from the unused TCL switch loom for switching on.

That's the only messing around Ive done with the electrical system.

You fellers had something like this happen before?


Edit: I've also noticed that my headlights and interior lights dim quite a bit while turning the wheel while stationary, and low speed maneuvering, while the revs are low. It's always done this a little, but nowhere near as much as it does now. I've checked my alternator, to make sure it wasn't packing up, it's putting out a constant 14.3 volts.

 

[sanchez]

You have a ground fault, when yr indicators are running ie pulse on/ off. From what you have said it's not a hard fault, otherwise you'd blow a fuse, if it's wired correct. So my understanding would mean that your negative is sinking through some other device. Maybe......

 

[sanchez]

I don't really know what's gone on but I would be looking for commonalitys between a/c and indicators because, from what you have said, it sounds like, when yr indicators are running that voltage ie sounds like yr fan is running slower is varying. It's easy to check, chuck a volt meter across yr fan terminals when yr blinkers are on. Trouble being that most general mulitimeters won't be able to give you an accurate reading as the voltage is pulsing on and off. It's a lot easier to capture with a meter that has max/min capture voltage capabilities.

 

[sanchez]

Ps take what I say with a grain of salt, I'm no auto eleco but I do work with dc systems.

 

[smitty]

Ok seems I have got it wrong. Turned the fan off this morning, and traced the pulsating hum back to the walbro fuel pump. Thanks for the tip rodrigo, but i'm not sure how I'd be able to apply it to the fuel pump while the car's on, with it being inside the tank....

I haven't done the fuel pump/battery voltage mod, and i'm not running an aftermarket FPR.

 

[sanchez]

Hey mate, how'd ya go with the above problem? You'll still be able to measure yr voltage somewhere in the circuit, obviously not right at the pump, however, it's got to be supplied externally, so I guess it's time to do some wire tracing, fun, not... Haha.

 

[smitty]

was wondering perhaps if I could make up some wires that connect between fuse/relay box and the relay, giving me the ability seperate the relay to test there. Just not too sure how safe it would be?

am I barking up the wrong tree?

 

[sanchez]

Yes you can. What you could do is, if you plan on lifting a wire, place yr mulimeter on amps and place it in series with yr coil. So you'd lift the positive off yr coil connect it to one lead of yr multi and then the other lead to where you have disconnected yr wire. You should see a steady reading whilst yr fuel pump is running. If not, you've got an issue which requires further fault finding. PS make sure you have it set on amps!