bobbyblue Posted January 12, 2019 Report Share Posted January 12, 2019 My back up lights went out and I have eliminated bulbs and fuses as the cause. So I am pretty sure it's the PNP / neutral safety switch on the transmission. My 2001 T5 V70 automatic has the old style connector - black and blue with 9 male pins -, so it's easy to remove the large connector and see the pins. The wiring diagram shows the color code for the two wires (White and Yellow) but doesn't seem to give the pin out for the connector. What I want to do is to test for no circuit in reverse, to make sure I'm right. So could someone tell me which pins on the male connector (3/71 I think) I need to test from? Thanks. Link to comment Share on other sites More sharing options...
Ihatespeedbumps Posted January 14, 2019 Report Share Posted January 14, 2019 Here is the wiring diagram for 01 V70. I'd be looking at the REM or the relay on the REM. Link to comment Share on other sites More sharing options...
bobbyblue Posted January 17, 2019 Author Report Share Posted January 17, 2019 Much thanks! I never thought of a failed relay. That makes sense because the BU lights simply stopped working. that's relay 2/80, isn't it? And that should be in the back, IIRC. PS - Found the relay location and number -- RM14. Going to check it this evening.. Thanks again Link to comment Share on other sites More sharing options...
bobbyblue Posted January 18, 2019 Author Report Share Posted January 18, 2019 swapping relays didn't fix it. Back to the pnp switch... Link to comment Share on other sites More sharing options...
Ihatespeedbumps Posted January 18, 2019 Report Share Posted January 18, 2019 Do you have power to the relay from the REM? You can find free online wiring diagrams for your car here https://cardiagn.com/2001-volvo-model-s80-v70-wiring-diagrams-online/ Link to comment Share on other sites More sharing options...
bobbyblue Posted January 18, 2019 Author Report Share Posted January 18, 2019 much thanks for the link. I have a wiring diagram but i suspect it isn't for my car - like for more current years. I hope today I can get to the car and start tracing. That is why I wanted to start with the PNP switch - find the two pins (I think the wire colors are white and yellow) on the 9 pin connector, check for continuity in reverse, then go from there. But I can work from either end. 🙂 The relay is easier to get to for sure. Sorry to say but I'm on a tight budget at the moment, and I am trying to avoid buying a PNP switch new, if I can. They seem to going for around $100 to $200. So, if I have to buy, I want to make sure it's the switch Link to comment Share on other sites More sharing options...
bobbyblue Posted January 20, 2019 Author Report Share Posted January 20, 2019 I found out that pins 1 and 2 on the 9 pin connector, are for reverse, so now I can test the switch, which was my original purpose. Test before throwing parts at the car.. I also learned that the AW55 -50 transmission is used on several cars - Saab, Nissan, Saturn, and yes, the PNP switch is the same for all cars. EXCEPT for the connector - a bit of plastic wire and metal difference and the price of the PNP switch changes from $31.00 (Saab!) to $270. Most everybody else's version connects directly to the switch with a standardized connector, but Volvo attaches wires to it and epoxy pots the wires in place. Except for that, it would be simple to build a wiring harness adapter and use any of the direct connect type PNP switches. And I learned that it is possible to cut off the pins that hold the switch together and clean it, then replace the pins with nut and screws, but I'm not sure I want to get into all of that, since I found a 9 pin Volvo PNP switch for around $75.00. Time is money. Thanks to all who helped me figure this out. Link to comment Share on other sites More sharing options...
bobbyblue Posted January 26, 2019 Author Report Share Posted January 26, 2019 And on it goes - I was sure it was the PNP switch. I got a parts yard one, (blue and black male 9 pin type) and tested it for continuity on pins 1 and 2. I also tested the original, in the car, and both showed continuity in reverse. So maybe it isn't the pnp switch. So back to the back of the car - recheck the bulbs and they are good. test fuse F4 (10A) and it is good. Turn ignition key to II and leave car in Reverse. check for power between F4 terminals - nothing. Check F4 terminals for power to ground (the big bolt that holds the relay and fuse box on) - still no power. Pull Relay RM14, and I can hear it click. Wiggle it and I can hear it click. Swap with another identical relay - still no lights. BTW, RM14 is all by itself on the top row of relay sockets, one in a group of four, to the left, and is the only one in the left hand group of four top row sockets that is wired. And I've never messed with the relays back there. So can anyone tell me what I am missing here? I really need to get the backup lights working so I can pass inspection before the end of Jan. Thanks in advance....... Link to comment Share on other sites More sharing options...
Ihatespeedbumps Posted January 28, 2019 Report Share Posted January 28, 2019 Do you have power out of the REM on the solid blue wire? My feeling is that if you have power into the REM, but no power out the REM is the common denominator with a known good relay installed. Also, have you checked continuity from the reverse light wires back to the REM? Link to comment Share on other sites More sharing options...
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