Extra Motorcycle: Qingqi QM200GY-BA

Notes on EFI relay types (Warning: Dull and boring)

Some advice concerning the electrical relays used on our EFI Bonnies. You may never need it but it may help in an emergency.

On the EFI Bonnies, we have a variety of relays, there are four altogether, all vital to the working of the bike and capable of leaving you stranded by their failure. All but the starter solenoid are plug-in, so spares can be easily carried and substituted.

The first one is the Starter solenoid (item 36 on wiring diagram), situated behind the left side panel. Failure of this component will mean the bike can’t be started. A sturdy screwdriver or spanner across the large M8 terminals should crank the engine and enable us to get under way.

In an emergency and when far away from a Triumph dealer any old 12 Volt solenoid will do the job. Modern cars don’t have one as such because it’s integrated in the starter motor, but classic car shops, junk yards, other bike shops, suppliers of spares for buggies, karts, quads, etc will have a suitable temporary replacement.

The second one is the the Starter Relay (item 38 on wiring diagram) situated just above the starter solenoid behind the left panel. Its function is to turn the headlamp OFF during cranking of the starter motor to ease the load on the battery. The type number fitted is a HELLA 4RD003520-13.

If you suspect failure it can be unplugged and substituted by an easily available equivalent at most good automotive spares shops. It’s a very common relay on cars, and the description to ask for is a 12 volts 20/30 Amp SPCO (Single pole change-over) relay, identifiable by having five terminals as in the photo. Price is around 6 Euros each.

The third one is the ECM Relay (item 23 in wiring diagram) situated under the seat next to the barometric pressure sensor. This is used to power the ECM computer and also serves to delay power OFF by one minute from the moment you turn OFF the ignition. The delay is controlled by some sort of latch circuit and serves to power down the ECM in a controlled manner.

The fourth one is the Fuel Pump Relay (item 55 in wiring diagram). This lives under the gas tank. I suppose this is used to spare the ignition switch from the high starting current impulse created by the inductive nature of the pump motor.

It also serves to turn the pump OFF when commanded by the ECM on receiving a signal from the tip-over safety switch that detects the bike falling over and avoid gas spraying around the hot motor if any hose ruptures.

These last two are the same type: OMRON G8HN-1A4T-RJ-12V, and I’ve found them impossible to obtain from auto spares shops. They’re quite rare and a bit special. The description is: Micro ISO plug-in relay, 12 volt 20 Amp SPNO (Single pole normally open).

The trick is to ask for a Micro ISO relay like the above but type SPCO (Single pole change-over). Now these have an extra terminal as shown, but the relay sockets will take it, as they have an unwired spare terminal position on them as standard.

It’s common enough to be available from electronic component suppliers such as RS or Farnell Components. RS reference is 535-2542 and costs 4.31 Euros. Farnell reference is 109-4086, cost 4.72 Euros.

God knows what Triumph charge for these.

If anyone is still conscious and hasn’t lost the will to live after this post, I will relate a little story concerning the Micro ISO relays.

OMRON, the makers of those relays fitted to my Bonnie is one of my company’s suppliers, so I instructed my buyer to get a couple of them as spares for me with his next order to OMRON. Back came the reply that those relays were only supplied to certain auto manufacturers and I couldn’t have any under any circumstances. Quick as a flash I blatantly lied: I know that man, I need some for prototype work of a highly confidential nature for one such auto maker in the UK, enough said. .

Within two days they sent me 5 free samples with their compliments.

Last edited by Forchetto; 03-01-2010 at 06:01 AM .

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