Weird White Knight Light Problem

[olznut]

My back-up lights are acting weird and driving me nuts. Last week, I noticed that all the reverse lights were on, truck and WK, then the fuse popped. Also noticed that the wire leading to the fuse got hot. Did some checking, noticed the relay was toast (put the meter on it, 80 ohms!), so I replaced that and put the fuse back in. Now, the WK works fine, BUT the truck bu lights are ALWAYS on. I've had these on for almost a year with no probs until now. HELP!!

 

[chuckwilson]

I think you have the wrong relay in it!!!!

 

[PVasilauskis]

Did you try disconnecting the WK to isolate it as a source of the problem or are you hardwired?



I'm just plugged into the 4-way connector so I can just POP it out if need be.



Which fuse popped?



Did you wire it into a trailer connector or into the backup lights themselves?

 

[olznut]

Did you try disconnecting the WK to isolate it as a source of the problem or are you hardwired?



I'm just plugged into the 4-way connector so I can just POP it out if need be.



Which fuse popped?



Did you wire it into a trailer connector or into the backup lights themselves?





I'm hard wired into it. I went from no reverse lights at all when the fuse popped (the old school glass tube fuse WK comes with) to when I pulled the fuse, the truck reverse lights work, then when I went to Radio Shack, they gave me a "12V auto relay" that plugged right in, to now, truck reverse lights on all the time, and the WK works normal, so I undid the fuse again, the truck lights work again, but no WK. I'm unaware of different relay types, but the only thing different on this new relay is that I had to turn the plug 1/4 turn for it to plug in, which doesn't seem different to me and I'm electrically incompetent. :{ Maybe I should call WK? I'm lost here.

 

[nickleinonen]

there are different types of automotive style relays. . there are some that are 87a/87 or 87/87 on the output pins. . 87a is NC, and 87 is NO. . so if your original relay was 87a/87 and both output pins are in use, and an 87/87 relay installed, it won't work quite right [could have similar symptons to what you are having] try going to an auto parts store and see the relays they have there.



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[PVasilauskis]

Just to clarify the above post a touch.



NC = Normally Closed, meaning the electrical contacts are closed/ON when power is NOT applied to the coil. When the low power controlling circuit does energize the coil, it pulls the contacts apart/open thus turning OFF the high current circuit.



NO = Normally Open, is just the opposite. The contacts are normally apart/Open when power is NOT applied to the coil and when the controlling circuit does energize the relay's coil, it pulls the contacts together and turns on the high current circuit.



Very commonly a relay has both a NO & NC contact with a common lead. With the coil de-energized the common lead is connected to one set of contacts and not the other. Energize the coil and it swaps, opening the circuit that was closed and closing the one that was open. (now that's my experience in electronics, automotive style relays my be different, being strictly NC or NO)



Radio-Shack is hit or miss when it comes to electronic help. You probably would have been better off going to an auto parts store, maybe.



I would remove the fuse and go back to normal lights and give WK a call to:

1) See if they have any better troubleshooting experience, ie. they've seen this before.

2) See if they'll stand by their product and send you a free relay if that's the problem.

3) There could be a cause and you are just seeing the effect. It could simply be a bad relay or it could be water getting into somewhere it shouldn't and they may be able to recognize this and provide assistance.

4) If it is the relay and they are not going to send you one for free you can either get the correct relay from them or at least they can tell you the correct type so you can get it yourself.





I will say this, you can not simply go by looks alone. Part numbers must match or there should be a cross reference chart stating one part is equivalent to another. Also, relays will sometimes have a schematic of what each lead is printed on the case, which can help is in ensuring each lead does the same thing for both. Heck you can always plug the part number into Google and see what it returns, maybe giving you somebodies equivalent part.