748 Electrical Problem

[donato]

Looking for some advice. Own a 2001 748s for 3 yrs - no problems. Washed the bike to prep for storage 1 month ago. Tried starting it today...no luck. Fuses seem ok and engine mgmnt relays fine. Didn't hear the fuel pump. Anyone have any suggestions on what to check next? Checked the wiring schematics and it seems that the Could it be the ECU? Appreciate any guidance.
thanks
don

[The Goochman]

I assume that you checked the battery to make sure that it is charged? I know, dumb question, but it is good to start somewhere.

Look for the simple stuff before you go looking for the expensive stuff!

Dave G
aka The Goochman

[Chris]

Any chance the sidestand is down or causing the problems?

The battery to starter solinoid cable may also have come loose (happened on my 2001 748).

You could also check the starter switch on the handlebar.


Chris

[Ken L]

Connection at the fuel pump relay, or corrosion inside the relay itself.

[donato]

Hi guys. Battery and sidestand ok, but will check fuelpump relay, battery solenoid and starter switch today.
thanks again,
don

[donato]

Hi there. Checked all of the fuses, key and starter switch - all check out fine. All the relays confirmed to work, however, one of the two engine management relays - pin86 which is connected to the pin 23 on the ECU remains open. I presume that within the ECU this closes and permits the EM relay to close - which then enables the starter switch. Strange thing is the bike has worked fine and the only change has been a very thorough wash....could the ECU be fried? Last question, couldn't find the fuel pump relay - any help in locating this? Appreciate your direction.
regards

[cm250to999]

no schematic in front of me,...would help
think I am correct in saying fuel pump relay is one of the two large ones sitting in tail of bike. The one to the fuel pump will click on with the key turned on for about 5 seconds then click off. Click is a good sign, but if contacts corroded no power actually transferred. It is fairly common for the relays to fail due to bad contacts.

Had a 695 recently with a dirty kill switch (run / stop on right bar) that gave pretty much the same result (no fuel pump cycle or stater motor operation).

It may be worth checking the main to sub harness connection on right side near subframe mounting, 4 or 5 wire plug.

Side stand switch can also fail, jumper at the harness plug is one way to check that.

Sorry, not sure how you are testing, but even a hundred or so ohms resistace across contacts is not good. resistance should be about the same as meter leeds touched together.

One tick me off issue with all models is the primary ground (follow negative leed to engine). All too often either a lack of torque, or useless "star" washer crumbling and again poor connection. If you find this loose, disassemble and clean, make a wish and toss star washer over shoulder then use a flat washer. Sorry last bit my own rant...same as subframe bolts not tight enough from factory for all years...makes me wonder sometimes.
hope this helps

[donato]

Hi Guys,
Thanks for your help. After checking/testing all of the relays, checking terminations etc per your recommendations, removing.disconnecting the kill switch etc.....found an intermittent connection at the sidestand relay connector - seems that one of the wires was loose in the connector. Problem solved.
Dont' know how to remove this chat board - but I will send a separate email to the moderator.
thanks again!
don

[ERIC SUMMERS]

Hello all,
For everyones information.There is a relay test jumper kit available.It consists of four modules that go between the relay and the connector base and has pin contacts protruding from the module. Alows easy access to test relays.It is manufactured by Lisle and the part number is 56810, more than likely available from N.A.P.A. or other auto parts suppliers. I bought mine from my Snap- On dealer under part # LIL56810 cost me $84.95 .More than likely $14.95 from N.A.P.A.
Tnxs. Eric

P.S. checked with N.A.P.A. $69.95 plus $8.00 freight to bring it in .