Bulb check/Auto choke relay clicking

[tb45owner]

Can anyone help with this one...
The Bulb check/Auto choke relay is clicking when the ignition is turned on to just before starting.
Pulled the relay out and found the voltage only at 8.8V, hence the clicking noise.
The auto choke on the engine is also clicking and that to is only getting 8.8V.

Checked the relay coil terminals to the battery -ve and getting 12V, so it is something in the negative wiring that is pulling down the voltage.

[threedogs]

Check earths but again Yendor is your man

[Yendor]

I think your about to have alternator problems. When you turn the ignition on does the red battery symbol in the dash light up?

Where/how did you measure the 8.8 volts? where did you put the multimeter probes?

Have you noticed the red battery symbol flashing while you are driving?

[tb45owner]

Thanks for the replies guys.
My alternator died and so replaced with a new one. This is when I noticed the problem. I measured the 8.8V on the base of the relay with the relay removed, pins 1 and 2.
The alternator is charging at 14.4V ok. I found a diagram that shows a diode in the negative leg of the relay, but am unable to locate it, any ideas where it would be located?
The car starts up alright, and when I feel the relay it is no longer vibrating?

Thanks again for the replies

[Yendor]

The bulb check relay earth runs through the alternator/battery warning light circuit in the alternator. That's why I asked all the question about the battery warning light in the dash.

If there is a problem within the alternator regulator or the wire harness running to the alternator it will cause problems with the check lamp relay and battery warning light. Most alternators will still start charging once engine revs reach a certain amount, even if the warning light circuit is faulty.

So this problem only started after a brand new alternator was fitted?

You need to check the two pin connector at the alternator, make sure it in connected correctly and the wires that go into the plug aren't broken. With the diesel engines it's common for the wires to break about an inch away from the connector.

With your voltmeter in pins 1 & 2 of the relay base for the bulb check relay, ignition on and your voltmeter reading 8.8 volts.

1. Disconnect the 2 pin plug at the alternator, what is the voltage reading?

2. With some wire, short the Yellow with a Black trace wire to ground, what is the reading?

Also what is the voltage reading in the Yellow with a Red trace wire?

The diode is there to stop the alternator from running the engine on when the key is turned off.

[tb45owner]

Hi Yendor, thanks for the detailed reply,

I have had the battery light and A/T overtemp light come on and off prior to changing the alternator. Had the transmission serviced a while ago and he said it could be the alternator but when we checked the charge voltage it was at 14V, and he wasn't sure then, so I guessed it must be a dicky connection! and as the car ran ok left it!

I have never heard the buzzing noise from the relay, until after I changed the alternator.

The 2 pin connector is good and no wires broken.

1. with plug out voltage drops to 0V, but the autochoke solenoid is still humming?
2.short yellow/black to battery -ve, reading 11.99V
3. voltage at yellow/black wrt battery -ve is 12.41V. wrt to pin 1 of the relay is 12.05V

Thanks again for your help

[Yendor]

Hi Yendor, thanks for the detailed reply,

I have had the battery light and A/T overtemp light come on and off prior to changing the alternator. Had the transmission serviced a while ago and he said it could be the alternator but when we checked the charge voltage it was at 14V, and he wasn't sure then, so I guessed it must be a dicky connection! and as the car ran ok left it!

I have never heard the buzzing noise from the relay, until after I changed the alternator.

The 2 pin connector is good and no wires broken.

1. with plug out voltage drops to 0V, but the autochoke solenoid is still humming?
2.short yellow/black to battery -ve, reading 11.99V
3. voltage at yellow/black wrt battery -ve is 12.41V. wrt to pin 1 of the relay is 12.05V

Thanks again for your help

Going by those results you have a faulty alternator, as long as the Yellow with a Red trace wire at the alternator also has 12 volts.

I'm just not sure what you are referring to "autochoke solenoid".

Where did you get the alternator from?