How many volts should I be seeing here?
Discussion
Can't seem to find an Electrical section in the Technical part of the forums, so I don't know if this is the right place.
The head unit on my MR2 Turbo stopped has barely worked properly since I bought it a few weeks ago, so I set about replacing it on Sunday. After taking it out, I now find that the new one I plugged in just flat out won't power up, and neither will the old one.
They do, however, work fine when plugged into my Corolla, so that rules out the head units.
The fuse is still intact in the MR2, and indeed the cigarette lighter socket still functions properly (which runs off the same fuse) so it's not that.
With a multimeter, I've checked the wiring. The ignition wire is getting around 11.86V when the ignition's on, should that be above 12V?
Also, the constant/battery feed wire is only reading just under 9V - should this be 12V too?
If these figures are too low, what should I be looking at in the car to boost them? Not a rewiring job, presumably?
The head unit on my MR2 Turbo stopped has barely worked properly since I bought it a few weeks ago, so I set about replacing it on Sunday. After taking it out, I now find that the new one I plugged in just flat out won't power up, and neither will the old one.
They do, however, work fine when plugged into my Corolla, so that rules out the head units.
The fuse is still intact in the MR2, and indeed the cigarette lighter socket still functions properly (which runs off the same fuse) so it's not that.
With a multimeter, I've checked the wiring. The ignition wire is getting around 11.86V when the ignition's on, should that be above 12V?
Also, the constant/battery feed wire is only reading just under 9V - should this be 12V too?
If these figures are too low, what should I be looking at in the car to boost them? Not a rewiring job, presumably?
The head unit that came with the car powered up at least, until I set about replacing it, so I'm assuming I may have pulled a wire somewhere and broken a connection somehow, if they should both be at 12V+.
As far as I can tell the battery is healthy, not confirmed with a multimeter yet but a 140mi drive home with the car (and numerous short journeys since) with lights and other electrical systems on didn't cause any of the usual discharging symptoms.
Looks like I'll have to trace the wires back then. I was kinda hoping to avoid that - being a Jap import it's a bit of a mess behind the dash where previous owners have added things like car computers and turbo timers etc.
As far as I can tell the battery is healthy, not confirmed with a multimeter yet but a 140mi drive home with the car (and numerous short journeys since) with lights and other electrical systems on didn't cause any of the usual discharging symptoms.
Looks like I'll have to trace the wires back then. I was kinda hoping to avoid that - being a Jap import it's a bit of a mess behind the dash where previous owners have added things like car computers and turbo timers etc.
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