Fuse Relay question?

[Guest Pegasus76]

Could the Theft System/Starter fuse relay on an 86 300ZX cause voltage drops if the relay is bad? For instance, as I previously stated in my last posts...Whenever I ground the starter and hook up everything properly and connected the ignition wire to the S terminal...The voltage drops to 0 volts from the S terminal, however whenever I pull the wire off the spade terminal...Voltage can be detected again. So I checked the wires to the Starter relay and whenever I pull out the relay, the voltage goes to a .45 constant...Whenever I plug in the relay, the voltage drops to 0. Could this be my problem?

[Here comes trouble]

Peg...you got me beat...all this time I thought you were having a problem with a first generation Z not a 300 zx.. one thing would be helpful in the future is to stick with only one post........... and then if the post gets "dated" and begins to disappear with failing response.... you can write "bump" on the post which will activate the post on a daily post. I wish I could be of assistance but 300zx's I know very little..

[PeterZ]

Pegasus 76: Yes, I have seen the big blue relays go out. But I recommend testing first. What I'm not sure of are your voltage readings. If you apply 12v to the "s" terminal (with something like a decent jumper wire) the starter should take off (just like it does out of the car) regardless of what the key is doing - or the transmission for that matter, be careful. Are you getting .45v with the "s" wire off at the solenoid and the key turned to the to "crank" position then nothing in the crank position when the "s wire is connected? If so there's a big voltage loss in the system. The "s" wire should have battery voltage during cranking. Any dash, alarm or stereo work done recently?

[Guest Pegasus76]

Yes, the S wire receives a consant .45v when not on the starter and jumps to a 12v whenever the car is "cranked". However, AS SOON AS the S wire comes into contact with the starter spade terminal, the wire loses complete power. Also, I've noticed that whenever the theft system/starter relay is properly plugged in, that's when the power loss occurs. Whenever I take out the relay, power is once again restored. Also, I put in a stereo system about a year ago, nothing big...Just replaced it with a CD player. Could a fusible link do this?

[PeterZ]

I would say no to a fuse link. They melt and go away like a fuse only slower. I don't think a "real" 12 source would normally go to 0 volts if all was well with the wiring. You should be measuring the voltage drop of the solenoid (the amount of volts necessary to pull in the solenoid) Since it goes to zero I think you are losing the 12 volt signal and have nothing left-wait- this thing clicks but doesn't crank right? I'm getting lost since the posts are seperated. A jumper wire from any good battery source to the "s" wire of a properly installed starter should make the engine crank regardless of Key position, transmission, etc. Does this happen? (please be careful) If so, your problem must then be in the power distribution from the battery through the key to the "s" wire at the solenoid. Please verify this for me. I'm intrigued. (I did all of this with tests lights until computers became involved and messed up everything.)

[Guest Pegasus76]

Yeah, whenever you directly use a wire from the B terminal to the S terminal...The starter spins. However, I noticed that sometimes the starter doesn't spin whenever I'm jumping the starter. I just got frustrated and took the car to a local mechanic, they did a diagnosis and said that the starter was messed up. Sometimes it would turn and sometimes it wouldn't. I'm hoping that's the case.