What does the ignition load relay do?

My '93 RRC LSE is having electrical issues. See this thread:http://www.landyzone.co.uk/lz/f16/big-mystery-one-big-brains-260872.html

Anyways, as I trace the schematic I see that all the faulty bits are connected to a line from this "ignition load relay". Could someone in the know be so kind as to explain what it does and perhaps even where it is located?

Just a guess but it may be a relay that disconnects most electrical systems when the starter is engaged (to allow max power to starter), sometimes known as a load alleviation relay.

Its used so all the power used doesn't go through the ignition switch, the ignition switch just turns the relay on to power every thing, and what kwakerman said also

Cheers to both of you. So this relay is what directs the power to starting process, correct? Do you know if it is also involved in sending power to other systems?

West Slope Rover said:

Cheers to both of you. So this relay is what directs the power to starting process, correct? Do you know if it is also involved in sending power to other systems?

Click to expand...

No, it isolates most of the vehicle electrics during the start sequence, once the key is back to the run position electrical power should be restored. This is why things like fuel gauges will temporarily head towards empty when the starter is turning

Kwakerman said:

No, it isolates most of the vehicle electrics during the start sequence, once the key is back to the run position electrical power should be restored. This is why things like fuel gauges will temporarily head towards empty when the starter is turning

Click to expand...

So, it disconnects everything else but the starter circuits, then restores electricity to the rest of the system once started? I don't mean to be dense, but I'm trying to figure out if a fault it it my be causing my weird heater problem. Thanks for your patience.

Have you actually measured the voltage in and out of the relay when the fault is present? If no output the issue could be burnt or sticking contacts, dodgy coil etc but could also be an intermittent supply to the relay coil so it is not energising when required.

Kwakerman said:

Have you actually measured the voltage in and out of the relay when the fault is present? If no output the issue could be burnt or sticking contacts, dodgy coil etc but could also be an intermittent supply to the relay coil so it is not energising when required.

Click to expand...

No. I don't even know if it can be an issue with what's going on with my car. I'll pull the cover under the steering column and have a look. Thanks again.

West Slope Rover said:

My '93 RRC LSE is having electrical issues. See this thread:http://www.landyzone.co.uk/lz/f16/big-mystery-one-big-brains-260872.html

Anyways, as I trace the schematic I see that all the faulty bits are connected to a line from this "ignition load relay". Could someone in the know be so kind as to explain what it does and perhaps even where it is located?

Click to expand...

The ign load relay supplies power to pick the heater blower relay but the cruise module is powered from a different source.

Perhaps you could rig up some test light bulbs on the blower circuit, then when it fails you will know where the power is lost.

owl said:

The ign load relay supplies power to pick the heater blower relay but the cruise module is powered from a different source.

Perhaps you could rig up some test light bulbs on the blower circuit, then when it fails you will know where the power is lost.

Click to expand...

I swapped out the relay with no improvement, after I found it, which took awhile, I pulled out the old one and swapped in another relay I had to no avail. I wish I had a garage. I'll keep plugging away, but I must move on to other things today. Cheers.

To give yourself a better grasp of what it does, have a look at the wiring diagram , and then you will see what goes thru the IGN Load Relay , and you can then work out if the problem you have is in any way linked .

tacr2man said:

To give yourself a better grasp of what it does, have a look at the wiring diagram , and then you will see what goes thru the IGN Load Relay , and you can then work out if the problem you have is in any way linked .

Click to expand...

Well , that's what I've done today and I've found that everything on the schematic associated with the ignition load relay is wonky, everything from my service engine light and parking brake indicator, as well as all the other issues described. Connected also to this circuit is a fusible link and the ignition switch. Does any body know where this fusible link is located? I can't find its location in RAVE. I swapped out the relay and it changed nothing so I'm guessing the problem is the power to the relay.

West Slope Rover said:

so I'm guessing the problem is the power to the relay.

Click to expand...

Or whatever controls the relay - you really need to get a multimeter on it rather than guessing

Kwakerman said:

Or whatever controls the relay - you really need to get a multimeter on it rather than guessing

Click to expand...

I removed the relay and went on the intertubes to see how to check it. When putting power to 85 and 86 I can hear the relay click but what should show up on the meter when making contact to 30 and 87? I had it set to resistance and the meter read .001.

Edit: Upon further investigation it seems that .001 is good reading.

After checking the rely, I cleaned up the connections at the alternator. When I turned the key, everything worked!! Cheers for the input.