or the LED lights? long story short, car blew a fuse now the AFR and boost gauge don't illuminate

going to un-do and recheck all wiring to them now (were working fine before)

 

LED's can be damaged by being over-driven (voltage/current to high), over-heated or being connected in reversed polarity. They nearly always (99.99999999999%) go open-circuit though, so shouldn't be blowing fuses. It's more likely to be a wiring fault. Have you check power + earth continuity at each gauge?

Chris

 

Yea I find a shotgun is a good thing to use if you enjoy blowing things up like gauges

 

noooooo..., fill the gauge with oxy-eceteline, covere the outside in wd-40, and spray a line along the floor laeding to the gauge,
take one match, light said line and happy days

 

I don't actually want to blow them up you fools

Pulled the headunit forward to reinsulate some wiring, carefully wedged it back in, reconnected battery then found a blown fuse (for the heater/instrument panel) so think maybe the headunit pulled on some wiring, could be unconnected

Will recheck the voltages later, both are fed from the same live and earth

 

im assuming the ignition was turned on then,
i would take the head unit back out and check all the wiring, trace it back and look for any bare or loose wires...

 

Exactly Danzul. Hardly rocket science, just hope the gauges haven't been knackered by a surge or something

 

i dont see why they would be,
if you have replaced the fuse and the fuse is still good and not blown again, then its possible there has been damaged caused else where, including the gauges.
i would get the multi metre out and check all the wiring, and the gauges

 

A LED when connected in revserse will simply NOT illuminate, it will NOT damage it at all, connect then correctly and it will be perfectly ok.
A over voltage or current as said will kill them, reversing will not.
tabetha

 

Try putting 12V backwards across an LED with a Vf of 1.4 then... Depending on the way the gauge drops the voltage to the LED you could see 12v at the diode if connected in reverse. E.g. a resistor would work the same way in either polarity, a zener would not.