Electrical question

[Roops]

Does the ignition switch feed the dash ? RS2 MKII, I have voltage at the battery isolator, lights work but when I turn the key the lights dim and dash is dead. Strongly suspect a rogue earth somewhere, or something in the dash draining the juice. Is this possible ?

 

TIA

[Col-ashtonmobile]

yes mate it does , check the multi plug that goes onto the dash printed circuit , pull it out and give it and the connector a good clean , hope this helps

[Roops]

Thanks very much. One final question. The Starter motor is not on the car (Going to install a gear reduction starter). So the main feed to it and Solenoid connections are not attached. Basically leaving the circuit open. Is this likely to cause strange results/readings if I am working on the other car electrics ?

 

TIA

[Col-ashtonmobile]

no mate it wont make any difference to other electrics whether the connections are on or not , just make sure the heavy battery cable and the small trigger wire are not touching earth if you turn the key to the start position whikst working on it

[Savvi]

If it's a Mk2 what type of starter have you got ?

 

Some of the later cars take the feed for inside off the solenoid / main battery cable with pre-enguage starters,in this case you would have more then one cable with the large ring termials on the main cable connector, in which case you may need to bolt them togeather and wrap it to stop it earthing out on the body whist working on it.

[Roops]

Thanks chaps good to know. Starting to suspect that the ignition switch may be the cause of the issue. The car has been painted and I know the inside was very dusty after prep. I don't see any voltage on the blade connector for the dash when you turn the ignition on and the one working headlight goes very dim. I have the same voltage coming into the switch as the battery is outputting. Should either of the other two connections on the switch output power once the switch is turned. That's what logic tells me should happen.......

[Savvi]

Yes you should have the same power on at least 2 of the other terminals on the switch when the key is on.

 

 

You should have 3 other posistions in total, posisition 1 for a radio, posisition 2 for full ignition, then posistion 3 for crank starter run when the key is against the spring.

 

The headlight could be just a bad connection on the actual light, however it couls be a sign that the body earths are not good, if it's been painted you will need to take off the paint under the body earths and put some grease on when connected to stop it rusting.

 

There should also be some earths inside the car coming off the main loom, check those.

[Roops]

Excellent. Thanks for the info. I will dismantle and clean the ignition switch as that sounds like the issue. I have nothing coming out of the switch at all, in any of the key positions. Will also go over the earths, I figured these would require attention after the paint job.