HOT Fusible Link!

[Turbo260Z]

Any of you Datsun guys have this problem before?:

 

First off:

2/74 260z

My car starts by a push and hold button once the key is in the on position. This is how it's hooked up from the PO. It's literally 1 wire from the battery> Push button>1 wire> starter. Does not run off any other wires or ignition, so I can run the starter with my key off.

- If i twist the key to the start position I would still hear the ignition relay click even though it's not hooked to the starter.

 

The other day I went to start my car and the ammeter gauge showed no charge, lights were dim too. I turned my car off and none of the lights worked/turned on. I then twisted the key to the start position and it didn't click the relay like it usually would do even though that's not how I start my car.

I started my car with the push button (like usual) and the ammeter was still not showing charge and all the lights were dim. I started it and shut it off a few times and the gauge finnaly showed charge and all the lights are bright and back to normal. They even turn on when the car is off.

 

The relay still doesn't click when I twist te key though. Even when I take the battery cable off and put it back on I don't hear a click from a relay like I used too ( the same relay I think).

 

Already changed the ignition switch. And checked all fuses.

 

Now my problem is that the fusible link for (what I think is) the ignition/starter is getting really hot. The fusible link that is getting hot bridges the thick white wires running from the shunt. The white thick wire is also hot at the shunt too.

 

When I disconnect the T plug at the alternator, the fusible link doesn't get hot anymore. The cap for the fusible links say BATT(for the one thick white wire that gets hot) and IGN(the one that doesn't and is white/red wire)

 

I have a feeling my problem has something to do with my ignition not clicking anymore. Also, when I would plug the negative battery cable back on, a relay would click too. Is this the same relay?

 

The relay clicks come from the passenger front kick panel.

Edited October 16, 2014 by Knault

[NewZed]

You should re-think what's happening and write a new description.  Most of your post doesn't make sense.  Read it back to yourself and you'll see.

[jhm]

You may have more than one issue going on at the same time; but in regards to your question on fusible links....yes, they could certainly be a problem.  They're a 40-year component that carry a bunch of amperage....go figure.     

 

Most guys replace them with heavy-duty fuses (e.g Maxi-Fuse) or relays.  Search on "replace fusible links" in the sub-forums and you'll find a ton of helpful info.

 

Regarding any other issues, best approach is to isolate and test....electrical gremlins can take time to track down.  It sounds like someone has installed a push-button start on your car at some point?  That might be a good place to start.  Here's a link to FSMs for all years S30s -- the wiring schematics can be your best friend in situations like this:

 

 

http://www.xenons30.com/

 

Hope this helps.

[Turbo260Z]

You should re-think what's happening and write a new description. Most of your post doesn't make sense. Read it back to yourself and you'll see.

 

Fixed it up, hard to write on here with my phone and work at the same time with this little screen haha. Thanks!

[NewZed]

Kind of sounds like 

 

- If i twist the key to the start position I would still hear the ignition relay click even though it's not hooked to the starter.

 started it and shut it off a few times and the gauge finnaly showed charge and all the lights are bright and back to normal. They even turn on when the car is off.

The relay still doesn't click when I twist te key though. Even when I take the battery cable off and put it back on I don't hear a click from a relay like I used too ( the same relay I think).

When I disconnect the T plug at the alternator, the fusible link doesn't get hot anymore.. Also, when I would plug the negative battery cable back on, a relay would click too. Is this the same relay?

The relay clicks come from the passenger front kick panel.

 

Kind of sounds like the ignition switch stopped working, and Start only gave On, with no starter action.  So the PO messed around with the wiring to make it run.  Added the push button to fix the no starter action problem, and maybe hot-wired the ignition relay.  It shouldn't click when the battery cables are connected.  That will drain the battery.  Does the car turn off with the key or do you have to drop the clutch with the brakes on?

 

The hot fusible links, with the T plug behavior, is probably a separate problem.  Maybe a bad alternator or voltage regulator. You'll have to dig around and see what else has been messed with.  There's probably more messed up than just the starting circuit.  Look for extra loose wires T'ed or spliced in where they don't belong.  The wiring diagram for the ignition switch circuit is pretty easy to understand.