What's This?

[catfish78]

OK, here's one for you guys.

I recently installed a stereo in my 280Z and came across this 'relay' against the passenger side strut tower. I suspect it is some sort of fuel pump shut off to the electric fuel pump as one of the wires lead to a toggle switch on the console.

Well of course I had to figure out where the other 3 of the 4 wires go that come out of this relay. One is grounded on the front of the car, one is connected to the white wire (in picture) that hooks up to the battery and the last one dead ends 2 feet from the relay. The one connected to the battery has an inline fuse that is so corroded I think the relay stopped working for the PO some time ago.

My problem is this: while installing my stereo I wiggled some of these wires in search of a live wire to my stereo. The next day, I couldn't start the car, it would just turn over and did not seem to fire. I suspected this relay had something to do with it. So I cleaned up the connections and voila it started. Well for the past few days, it's done the same thing. So I wiggle the connections around this relay and once again it starts. Now this is the kicker, I only have this problem when the car is dead cold. When it is warm, even after a few hours of sitting, it starts no problem.

I've cleaned up all the connections, still no better. I've even disconnected all the wires to this relay when it is running and the car keeps running! :tapemouth If any of you guys can cast some light on this I would really appreciate it.

Thanks,

Mike

[cremmenga]

its not the one by the coil is it?

[catfish78]

Nope, the coil on my car is located on the driver's side of the engine bay, close to the air flow meter.

The relay in the picture that I'm referring to is the one with 4 visible wires coming out of it (2 red, 2 black). It's right on the curved part of the strut tower (sorry, first time posting a picture. I couldn't figure out how to add an arrow to the part I'm talking about).

[cremmenga]

oh shoot when i opened it there was no picture sorry, must have opened it right as you put it up. but ya I don't know what that is, i had one similar to it inside of my car down and the passenger side under the dash? it wasn't hooked up so i took it out.

[catfish78]

my bad, first post didn't take pic! I edited and added pic after it was posted.

[Grim]

I don't believe it is a stock part. my 78 doesn't have it and I couldn't find anything about it in the repair manual.

[kenz240z]

From your description, it sounds like this relay isn't doing anything. I'd guess that one side of the toggle switch is hot. When the switch is flipped, it would trigger the relay, which would then connect the battery lead to whatever was connected to the dead-end lead. So it would seem that the relay was there to provide power to something.

If it was my car, I'd take that relay out, and remove all questionable wiring associated with it. Wiggling the wires attached to the relay could have tugged on another connector somewhere, which might be causing your cold starting problem.

[wal280z]

I don't believe it is a stock part

Nope, it's not.

If it was my car, I'd take that relay out, and remove all questionable wiring associated with it. Wiggling the wires attached to the relay could have tugged on another connector somewhere, which might be causing your cold starting problem.

Agreed!

With the key turned to on, grab the wire harness that is between the fusible links and the white wire tap off the starter. Wiggle that to see if you hear relays clicking on and off. If that's the case, you need to repair your harness before going further.

Wayne

[catfish78]

Thanks for the tips, guys. Like I said, the relay looks about as old as the car is so it was hard to tell if it was original or not. With that solved, I'm pulling it out.

I disconnected the red wire from the suspect relay that was spliced to the white wire, tried starting it and didn't get it to fire. Pulled apart the wiring harnesses for the white wires and a pile of corrosion fell out. Cleaned up the contacts and it did finally start. Looks like the wiring harnesses had a poor connection and when the wires were wriggled it got just enough juice to start it. If I have trouble starting tomorrow when it's cold, likely that relay and the associated wiring is too corroded.

I'll try this theory tomorrow and repost to let you know!

[catfish78]

bad news, no improvement :disappoin

Cleaning up the contacts didn't make a difference today. Tried to start it and it turned over and over and over... Wiggled the connections and associated wiring and it started no problem.

Disconnected all the wiring with the suspect relay tonight, at least I feel better that it looks cleaner. Could be any number of wiring connections, guess I'll have to eliminate each potential problem one by one to get to the root cause.

Thanks for listening. Any more insight would be welcome!

PS - any other 280z owners out there, if you could post a pic of the same area of your engine bay so I could see what the wiring looks like I'd appreciate it. Wiring diagrams are great, but as they say a picture says a thousand words!

[cremmenga]

I cleaned out my engine compartment one night! I started by taking out each wire that wasn't doing anything. I pulled one and checked to see if it would still start, then I pulled another and repeated that about 20 times! I had wires that weren't conected to anything at either end. it was crazy!

[catfish78]

surfing around I found a fantastic tech tip at the Atlantic Z club web site on cleaning connections. I've used this site many times in the past. Great for the do-it-yourselfer's out there!

Looks like I've got my work cut out for me this weekend.