Sunfire backup lights not working

[viper1230]

I have a 1999 sunfire gt with a five speed and I was recently told I didn’t have reverse lights. I bought bulbs to replace them to only find out that the current installed bulbs are NOT blown! Being that I have a 5-speed it has a backup light switch on the trans so I think that is not working, but before wasting money on another part I take off the connector and test to see if it has voltage and it does NOT have voltage. But I don’t know if it has any inline fuses or if I need to have the car ignition turned to the “on” position for the switch to be activated.

Topic

[viper1230]

I would have to guess that it might be damaged internally if that is possible as the outside of the sockets look great. No corrosion or damages.

[college man]

the diagram you posted is the one I just saw on bbb
go to bbb put in info. under system lighting then
sub system reverse lights. the entire print is there

[viper1230]

Here’s the full diagram…but where do I find where the ground is actually located without tearing through the car to follow wires?

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• image_2012-10-26.jpg

[college man]

find the black wire at the reverse light socket.take a jumper
wire from the black wire to a clean chassis ground. see if the
lights come on.

[spelunkerd]

With the ongoing discussion regarding this repair, I signed on and then realized that collegeman said what I was going to say. The way you described how the voltage drop fell when you put a bulb in the socket with power on, it was basically a voltage drop test. You showed that the major source of resistance was distal to the bulb, ie diagnostic of a bad ground (as Eric pointed out). So, if you can’t find the path of your ground wire then I would bypass the ground wire to the frame of the car, to see if your problem is solved. It’s not ideal to fail to identify the site of the problem, mainly because there could be other circuits involved, and sometimes even reverse current flow from other circuits if you leave the bad ground wire in place. But it may be a quick solution to completely replace the ground wire.

[EricTheCarGuy]

[quote=”spelunkerd” post=35497]With the ongoing discussion regarding this repair, I signed on and then realized that collegeman said what I was going to say. The way you described how the voltage drop fell when you put a bulb in the socket with power on, it was basically a voltage drop test. You showed that the major source of resistance was distal to the bulb, ie diagnostic of a bad ground (as Eric pointed out). So, if you can’t find the path of your ground wire then I would bypass the ground wire to the frame of the car, to see if your problem is solved. It’s not ideal to fail to identify the site of the problem, mainly because there could be other circuits involved, and sometimes even reverse current flow from other circuits if you leave the bad ground wire in place. But it may be a quick solution to completely replace the ground wire.[/quote]

I’m not a fan of this practice for the very reasons you pointed out however if you’re in a bind you’re in a bind and at least you could get by till you fixed it for real. I would think a ground for a tail light circuit shouldn’t be too hard to find however. Also I can’t stress enough how often I see bad sockets cause issues like this. Make sure you have power and ground to the socket itself and that the bulb is making good contact inside of it.

[viper1230]

Well they were working properly before hand, which is why I thought it was blown bulbs.

[Author]

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