SR20 Charging System Dash Light

[Ashers]

Hi all,

Have had issues with my charging system on the 14a SR20 fitted in my PS13. Decided to start having a look and see whats up with it last night.

First of all I've checked that there is continuity between the positive terminal on the alternator and the positive battery terminal in the boot, which there is.

With the ignition on there is no charge light on the dash. Removed the clocks and checked the bulb. Its fine. Fitted it both ways in the clocks. And checked the continuity of the circuit board on the back of clocks. All is good up to the where the plug fits in the clocks.

Pictured below is the plug for that end of the clocks. The wire for the charge light is the red and white one up front of the picture, left of the blue/black wire.

I need to know what this does and where it goes. My guess is that its a supply to the bulb to illuminate it?

I have heard that the system won't work without the charge light lit as it creates a small amount of current or something alone those lines.

Be great if a wiring guru or someone in the know could gimmie a hand as this is the last issue I've got with the car. It drives but eventually the battery dies and needs to be charged.



Thanks,
Ash

[s14@jim]

The signal for that wire comes from one of the small wires on the alternator, without it connected the alternator will never get a 'start charging' signal so will never charge the battery.
At a guess you've gone wrong at the start charge loom somehow... I don't know 13 wiring very well though.

The dash bulb has a positive supply to it, with ignition on it earths through the alternator, when the engine starts and alternator charges the earth path becomes live, the bulb has a live at both terminals and no earth it so goes out. If the alternator fails then the earth returns and brings the bulb back on

[Ashers]

The signal for that wire comes from one of the small wires on the alternator, without it connected the alternator will never get a 'start charging' signal so will never charge the battery.
At a guess you've gone wrong at the start charge loom somehow... I don't know 13 wiring very well though.

The dash bulb has a positive supply to it, with ignition on it earths through the alternator, when the engine starts and alternator charges the earth path becomes live, the bulb has a live at both terminals and no earth it so goes out. If the alternator fails then the earth returns and brings the bulb back on

One of the small wires on the alternator? Would that be on the plug that fits into the alternator? If so I'd wanna be looking for continuity between there and the plug at the dash. Or would it be in the loom somewhere?

I'll see if I'm getting 12v at either side of the bulb when the ignition is on. And also an earth on the other side.

Thanks man!
Ash

[redsx94!]

Pretty sure without the charge light being connected it will still charge however there is another wire on the same plug on the alternator that is the start charge signal wire.

[Ashers]

Had a quick check today on this..

Looked for continuity between the red/white wire above and either of the white wires on this plug pictured below. The one of the side of the alternator.
There wasn't any continuity on either wire.

I need to know if I should be looking for continuity on this plug or not? Or if theres another plug somewhere with the start charging wire?


Ash

[Dal]

ok this of top of my head but on the two pin plug the smaller in diameter wire is the dash warning light should run directly to one side of bulb, usually a white/ red strip wire you can pick up in the 8-pin green? plug near fuse box please double check though, other side of bulb is ign supply
The larger wire (in 2 pin alt plug) is a battery voltage sense and usually picks up from the main white ignition wires in fuse box
without either the alternator will not charge
hope this helps

[Ashers]

ok this of top of my head but on the two pin plug the smaller in diameter wire is the dash warning light should run directly to one side of bulb, usually a white/ red strip wire you can pick up in the 8-pin green? plug near fuse box please double check though, other side of bulb is ign supply
The larger wire (in 2 pin alt plug) is a battery voltage sense and usually picks up from the main white ignition wires in fuse box
without either the alternator will not charge
hope this helps

Done a bit more checking yesterday.. The smaller wire I've traced to the alternator fuse (which I've checked to) but from the fuse onwards I'm having trouble. There isn't continuity from the fuse to either side of the charge bulb at the dash. So if that's where it should be going to there must be a break somewhere?

The larger wire from the alternator plug, I managed to trace back to my distribution block that goes back to the battery. At first there wasn't continuity so I removed it and put it back in correctly so now that should get 12v. Unfortunately the battery is on charge at the moment so I haven't been able to see if it's any better.

Main thing I need to find out now is where to go from the alternator fuse to the clocks or wherever?

Ash