Stumped here, hoping I’ve missed something obvious. Currently, none of my switched 12V accessories work, such as the lights, turn signals, etc. I’ve traced the issue, I think, to the DC relay but swapping it hasn’t fixed it. Here’s where I’m at:
- I can measure 12V out of the DC converter
- The “horn” circuit, which is unswitched, works. There is 12V power to the horn fuse and the horn.
- The 20A “switched” circuit, does not have 12V power at the 20A fuse up front.
- Prior to the 20A fuse is the DC Relay.
4a. If I bridge the “hot” pins on the relay (30 & 87), then the lights, turn signals, etc. work. The multi-function switch on the steering column operates them as normal.
4b. On the DC relay, I have 12V power to both of the RD/BU pins - 85 & 30.
As I understand it, the DC relay works when pin 86 is grounded (or un-grounded?), operating the relay and connecting the “hot” line. As above, if I jump this connection manually, everything works. I’ve tried a new relay, and also swapping the horn relay, no change.
QUESTION: is there something dumb I’m missing and it’s not the relay at all, or is there some further way to troubleshoot this?
NOTE: The PO had installed a 5-pin Sevcon DC converter which went bad, and I recall mention that previously a separate switch had been installed to power the lights, but I’m not seeing any of that in the wiring. The only other weirdness is that the bad converter (5-pin) had a “switch” wire, but it just got tapped 72V power (no switch) and the new converter (4-pin) has both the 72V (+) and “switch” line going to the same pin. I’m not seeing how this could matter, but mention for the sake of completeness in case it’s a clue.
Any help greatly appreciated, thanks!