Grand Prix 250
Join Date: Nov 2006
Location: driftwood, texas
Thanks to everyone for trying to help. I have just again tried to repair the motorcycle – been busy with work and lost my laptop to a bad motherboard recently. Anyway I have been back on the problem today.
I do not have an alarm, and yes the neutral light illuminates when the key is turned on. Fuse 8 is fine.
Also I may have messed things up when I first encountered the problem. I looked in the shop manual, saw the cluster of relays under the seat and swapped their positions to see if perhaps the relay was bad – it made no difference on the problem, but now I don’t know which relay is which. They are externally identical as far as I can tell, same BOSCH number, same pins, same diagram on the side, everything - is there a way to distinguish the appropriate relay?
So here’s what’s going on.
At my Fuel Pump relay socket, I found +12V at the Purple/Green, and when switched on 12V at the Green/Red wire.
I have power to both purple wires at the ECM Main Power Relay, however I’m NOT sure the correct relay is installed in that slot!
By swapping relays/positions I was finally able to cause the Black/Purple on the Fuel Pump relay to go 'low' when the ignition first turned on for 3 secs, then it jumped to about 6.8 V. After turning off the key switch, voltage holds at 7.25 for a few seconds then an audible click is heard from the relay and voltage drops to zero. The output voltage from the Fuel Pump Relay at the Purple/White wire never gets above 0.25 volts. So maybe the Fuel Pump relay really is the problem.
12V is available for the two purple wires on the ECM Main Power Relay, also on the Yellow/Brown when the key is off. Once the ignition is switched on, Yellow/Brown goes to about .25 volts in concert with the Fuel Pump relay voltage cycling on Black/Purple; also the Brown/Pink wire gets full voltage.
That’s the story with the current permutation for the 3 identical relays. I did study the BOSCH relays and they have small numbers stamped in the sides, and these numbers are different for each relay. I don’t know if I’m looking at a date/batch code or perhaps a specific application identifier. I know that voltage behavior for the various wires varies with relay permutation.
Is there a way to test each relay, and to determine its intended application?
Thanks, I want to ride the old T595 so badly. I placed an order for it long before they were available (in 1995 I think) and I got one of the very first ones built, back when they were still polishing the frame at the factory. My dealer told me they quit doing that after the first week, and subsequently changed to simply painting the frames, so only a handful were built in that manner. It still has less than 5000 miles on it.