Battery Drain - Ignition Relay Clicks on as soon as positive terminal is connected

s2k_adz

s2k_adz

Club Member
Hey all!

Finally got my datsun on the road but Im having an issue with the battery draining overnight.
The Ignition relay seems to click on as soon as the positive terminal is connected.
Any idea what might be the cause of this?
 
I guess a faulty ignition switch is a possibility. Have you confirmed it's the ignition relay rather than the accessory relay?
I think even with the relay activated, *something* needs to be *on* for the battery to drain.
 
jonbills said:
I guess a faulty ignition switch is a possibility. Have you confirmed it's the ignition relay rather than the accessory relay?
I think even with the relay activated, *something* needs to be *on* for the battery to drain.
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Hey Jon thanks for your reply!
Yea its definitely the ignition one. If i pull the cable on top of the relay then connect the battery it doesnt click so I assume this means its that relay?
Ill check out the switch although nothing else works in the car when its on bar the clock. You have to turn the switch a click to make lights etc come on as id expect
 
s2k_adz said:
Hey Jon thanks for your reply!
Yea its definitely the ignition one. If i pull the cable on top of the relay then connect the battery it doesnt click so I assume this means its that relay?
Ill check out the switch although nothing else works in the car when its on bar the clock. You have to turn the switch a click to make lights etc come on as id expect
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That’s the fuseable link you are pulling out
with it out you are basically disconnecting power to one of the main feeds to the fusebox
So with it out see which fuses loose power it will more than likely be one of them that’s staying on
 
Rob Gaskin said:
The reason I asked is that I'm not aware of an Ignition Relay. There is an Accessory Relay as Jon asked earlier in the Thread.
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Maybe its that clicking? None of the accessories can actually be used though until I turn the key to the ACC position. I think Neil mentioned today it might be something to do with the alternator charging?
 
Hey guys,

A bit more investigation today. If I attach the battery and then pull the ignition fusable link under the bonnet it makes the same click. This is coming from the box that sits below the fusable links on the drivers inner wing.

Detatching the ignition switch does nothing to stop it so I assume that means the switch is OK?

The click is under the black bracket with the fusable links attached:

20220827_150814.jpg
 
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The Alternator voltage regulator sits under/behind that black bracket, in your picture you can see one of the screws holding it in place poking through from the back.
 
toopy said:
The Alternator voltage regulator sits under/behind that black bracket, in your picture you can see one of the screws holding it in place poking through from the back.
Click to expand...

It's that that's clicking on I believe. What would be causing that?
 
s2k_adz said:
It's that that's clicking on I believe. What would be causing that?
Click to expand...
Honestly, no idea how they work or why it would click. Checking and cleaning the alternator connections and the regulator multi connector would be a good start i guess. The regulator is a mechanical/analogue device, no fancy electronics and there is also no relay involved, certainly never heard mine click and don't believe they are supposed to.

I have a new internally regulated 280zx alternator and the required plug in adapter for the original regulator wiring, just haven't got round to fitting it yet.
 
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I've lost track Adam - can you recap what you know and what the problem is? have you identified what is actually clicking? where's the sound coming from?
 
The clicking comes from right below where that ignition fusable link is. Under the bracket it sits on.

Been told it could be the alternator voltage regulator?
 
s2k_adz said:
The clicking comes from right below where that ignition fusable link is. Under the bracket it sits on.

Been told it could be the alternator voltage regulator?
Click to expand...
I would unbolt that bracket and check it is just the voltage regulator behind there, if it is, unplug it and see if something else clicks!
Don't attempt to start the car with it unplugged though, doubt it would do the alternator any good.
 
So after a conversation with @Fairlineguy we got to the bottom of it! Apparently Datsuns had a couple of different alternators one with something built in and one with whatever that is, not built in.

I had a spare one so I chucked that on and it's now perfect. I think I had the original L28 alternator fitted and needed the L26 one off my car.
 
s2k_adz said:
So after a conversation with @Fairlineguy we got to the bottom of it! Apparently Datsuns had a couple of different alternators one with something built in and one with whatever that is, not built in.
Click to expand...
Regulator, externally as for 240z and i believe most 260z, internally for 280zx and IIRC for later 280z
 
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