1997 850 Reverse Lights

davolvo · Post by **davolvo** » 08 Feb 2015, 23:01

Hello, my reverse lights are out. The fuses and bulbs are good. My mechanic says that he does not have a manual or whatever on the wiring for the reverse lights. Does anyone know where I might be able to attain one of these? Thank you.

Post by **erikv11** » 08 Feb 2015, 23:20

Hello, it is very common to see this behavior when the car has a failing or dirty PNP switch.

Try this: with the car turned off, row the shifter back and forth rapidly about 25 times through all the gear positions (really). This will help clean up the grease and contacts in the PNP switch, and usually gets those lights coming on again.

Also: with the car backed up toward a wall or something, try moving the shifter just a little bit one direction and then the other, from the baseline reverse position. Look in the mirror at the wall; can you get the reverse lights to come on? If so, then it is a PNP switch problem.

And finally, if the mechanic didn't know to look at the PNP switch, then he may know little about fixing these cars, and you should really look for another one. There should be several mechanics with good, basic Volvo knowledge in most parts of Wisconsin.

davolvo · Post by **davolvo** » 09 Feb 2015, 05:22

Well, the way he said it, and I may have misunderstood, was that it could also be something in the PRND3L and did not want to assume it was the PNP without a wiring diagram. I live in a very rural area in Wisconsin. I did have an actual Volvo specific mechanic in Illinois but he can no longer accommodate my work hours and I have no alternate transportation. Thank you for your help, I will try your suggestions.

Post by **cn90** » 09 Feb 2015, 07:09

Search for that infamous PNP theard in this forum and you will see that the fix is easy if you own basic tool and can read instructions.

Been there done that and I fixed my "no reverse lights" issue for free.

Post by **erikv11** » 09 Feb 2015, 09:24

Sure, it could be something else. It is just that he can test the PNP instantly by the described method and 9 out of 10 that is the issue, so it is odd that he didn't.

Give it a try, hopefully it is just the PNP (common) and not wiring (rare).

Post by **TRuck** » 26 Mar 2015, 23:14

Hi,
I am helping out a friend with a '98 S70.
No reverse lights. Fuse is fine. Bulbs new.
I tried the "rowing" through the gears...about 100 times.
No dice.
Inspection is by April 1. I don't have time to do the PNP clean up for her as described in that thread.
Any suggestions? Something different to do for an S70?
Thanks much.

Post by **erikv11** » 26 Mar 2015, 23:52

With respect the PNP, the 98 S70 is mechanically exactly the same as a 97 850. The tail lights are different but everything else is the same.

It could be the wiring and maybe someone can suggest some tests for that (sorry I'm not great with the wiring diagrams ...) but much more likely, the PNP contacts are just shot.

Post by **precopster** » 27 Mar 2015, 07:56

Rowing it 500 times may make no difference at all if the PNP contacts are totally shot. Our 850 had no reverse lights and no amount of rowing could even make them flicker.

I dove in and repaired the PNP without pulling it right out as the connector removal had me stumped and it took all of 1.5hrs. Reverse lights were restored and was driving much better as trans used to hesitate to shift into 2nd gear on cold mornings before the repair.

Post by **erikv11** » 27 Mar 2015, 08:15

precopster wrote:Rowing it 500 times may make no difference at all if the PNP contacts are totally shot. ...

Oh yes, absolutely. Maybe that was not clear, thanks Mike.

Post by **TRuck** » 27 Mar 2015, 12:03

Thanks guys.
@precopster...was your repair cleaning of it? or replacing it completely? ....in regard to it potentially being totally shot.