anthony_c

"...wire the car to use the ignition to power the relay coil and get a 78 oil pressure sender. Swap in a typical automotive relay..." Any solution that bypasses the original relays. They have become a perpetual nuisance. @SteveJ do you have a preferred place to connect the relay coil w/o cutting existing wiring?

i like it, my only concern is that is a one-off product. what happens when it fails and replacements are nla.

the 260 has (or at least mine does) two factory fuel pump relays. one triggered by the alternator, the other by the interlock relay. and if i could i would yank the whole mess and switch to a mechanical fuel pump.

it's been several months since i looked at the wiring diagram, but before your completely bypass the interlock watch out for the fuel pump relays. one of them is triggered by the interlock system.

yes i do. for the sake of not having to exercise that knowledge at the roadside i would still like to install a new relay and find a different power source for the coil side.

"The first place to check the voltage on the yellow wire is at the voltage regulator." - I'm measuring 7.5v on the yellow wire at the alternator and at the relay. Enough for the original relay but not the new mini-cube. and now it magically works again. ughh. would rather it stayed broken long enough to identify the fault.

"need a relay with a pull-in lower than 8 Volts" @Captain ObviousI dare you to try that line at your local parts counter ?

@SteveJThanks for the clarification. I have been referring to the diagrams but didn't realize FPR2 was NC and served as a kill switch when the starter was activated. For the record I couldn't understand why they were pulling coil power from a circuit that was only active when the starter was engaged, but now it does make more sense. As to why I'm working on this, the P.O. must have run into a problem at some point and hastily re-wired the relays in a rather non-conventional manner, pulling coil power for FPR1 from the fuse panel and bypassing FPR2 entirely. I was trying to normalize what he had done and make the arrangement closer to stock but suspect I have encountered the same issue he did. I'm not getting enough voltage from the alternator to consistently trigger the relay. Sometimes it works, sometimes not. I took the alternator to a local remanufacturer and they could not identity the problem, so I purchased a reman alternator from ROck Auto. Same issue. I'm not getting enough voltage to trigger FPR1. Hoping for an easy fix I picked up a new generic 4-pin relay from Napa but that was no help either. At this point I probably need to start working my through the harness to find where the voltage drop is occuring. My suspicion is the patch panel under the dash on the passenger side. Those mini-bullet connectors seem to be the cause of many of my problems.

260 actually has two fuel pump relays, one controlled by the interlock relay, the other by alternator, both by way of a yellow wire. neither is putting out enough voltage to reliably trigger it's respective relay. for the moment i'm just using one of the relays and inserting jumpers as needed to get power to the fuel pump. and yes, everyone is helping! thank you.

my initial guess was that the original relay had failed so i picked up a generic mini-cube type relay at napa. after some additional testing i found the voltage on yellow is hovering around 2v. if i crank the starter it rises to a max of 8v. probably not the relay.

reference "interlock relay" and work backwards from there

Most of Bosch's relays show a pull-in voltage of less than or equal to 8v but they don't explicitly indicate a minimum. Did they mean >= 8v, or is the stated drop out of 5v also the minimum pull-in.

does anyone know offhand how many volts it takes to trigger one of the bosch style mini-relays?

As SteveJ mentioned earlier, in order to run LED's on a US spec 74 260z I would need to re-wire the dimmer switch to switch on hot instead of ground. I'm not prepared to go that far so will probably just drop in a relay and be done with it. Depending on amp load I may upgrade to halogens, but tbd.

AK260, In the states we look for the "D.OT. Approved" label. Lots of options on amazon, none with a brand name that i recognize.