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no lights or mfd.

H

heinalanka

Free Member
I just installed my motor after I rebuilt it, and I now have no lights or display readout. the motor runs great, I have rechecked all the plug ins and cant seem the see any I missed, there are a few that arn't pluged in, every thing worked before I removed the engine. any body else have this problem. I am also looking for a wiring diagram so I can check. my sled is a 2006 swithback 900. thanks in advance. :confused::confused:
 
swampdog

I just solved that exact issue literally minutes ago out in the shop. I have 05 900 switchback, rebuilt top-end, started up- ran fine, but no lights, mfd. After checking chassis relay, red power wires to the relay and white/black ground wire from relay going to ecu (tested fine) , out of curiosity I grounded w/b relay ground to chassis ground with jumper wire and lights/guages came on! Luckily dealer had extra ecu I was able to swap-out for diagnostic purposes and then go from there kind of thing, it works/runs great so in this case, bad ecu for me! Hopefully yours will not be such an expensive fix! Definately look to your chassis relay first and go from there, good luck!
 
sounds like a chassis relay. Check your local autoparts store. I got a better replacement at NAPA Auto parts for cheaper. Easy to trouble shoot.
 
I had the same electrical problem last year. With the sled running, check the white/blue wire for voltage. With mine, it had a positive voltage and I ended up changing out the ECU to fix the problem.
 
thanks will check for wiring problems I have a new chassis relay in and it still don't work. will look at it this afternoon, the dealer is lending me his shop manual for wiring diagram. hopefully find a wiring problem rather than a ecu problem.
 
well I found that I have no power to the red /white wire at the chassis relay, I have power on all the other wire when running. when I jump power to the red/white wire every thing works. traced wires and no luck. what turns on the relay, could it be the ecu?
 
read the info from MH and was wondering about running a external ground to the relay, since every thing else works at this time. still going to check with an ohm meter all grounds, hopefully wont need a ecu.
 
I think SW indicated above that he had grounded the white/blue wire and then lights and mfd worked. ECU corrected his problem.
 
thanks for all the help, I was hoping not to have to buy a ecu. spent lots on engine and up grades allready, wierd that it all worked fine till I pulled the engine and reinstalled it. seems to coincidental, to loose the ecu after the new engine.
 
I'm pretty sure I had the same thing happen last year after I had my hood off, but it was just the connector up close to the hood hinge. Jiggled it around and cleaned it and added some electrical grease. Maybe it's that simple
 
Napa relay fried my ecu.

I had A problem with lights and mfd cutting out intermittently. I bought the relay from napa that that was sugested in this fourm and it fried my ecu.
After I instaled the napa relay, that pull on the rope cost me $350.
There is some bad info in this thread and the one linked to it. be carefull!!!
Someone on here said the napa relay was better built and cheeper----LIAR--.
The napa relay was $18 and fried my $350 ecu
The polaris relay was $9.95 and fixed it after I spent $350 on the unnessary ecu::mad:
Rob
 
Same problem with my buds 05 RMK900 last year. Determined that the relay driver in the ecu is fried. So, being that he did not have the money for a new ecu, this is what we did.

Spliced into the white/blue wire, or is it blue/white? that goes into the chassis relay, then ran that wire to a toggle switch, then a ground wire to the chassis ground to the switch. When he wants to start the sled, he has the toggle switch off,all available power to the injectors/fuel pump and then once it starts, he flips the switch on, and then the mfd/headlights/warmers/taillight all work. Not sure what the long term problems might be, but we are going to find out. LOL. He has about 150 miles on it so far like this, no issues yet.
 
heinalanka said:
well I found that I have no power to the red /white wire at the chassis relay, I have power on all the other wire when running. when I jump power to the red/white wire every thing works. traced wires and no luck. what turns on the relay, could it be the ecu?
Click to expand...

No power at the relay means grounding the little w/b wire wont work.
Where did you jump the power from to the red/white wire.
Did you figure out the problem yet. voltage regulator?
There is a voltage reg test in the deep power manual.
Rob
 
Trying to solve the same problem...

....and had it into the dealership to check all components. Everything checks out okay, with the exception of not being able to swap out the ecu to see if it is a ground problem. We did the relay test to check for ground and it test's okay...
So...I have run a continuity test on everything from the relay back and everything that ties together...no change in continuity.
One question....I'm not an electrician sooo....if I disconnect the chassis ground and touch the tunnel or anything else metal while touching the chassis ground wire, I shouldn't have continuity should I...?
But everything runs great and works great...power to where power should be...starts fine, idles fine...Have ridden 80 miles or so and no issues other than the lights and mfd like Hienelanka....weird ****..
 
On the jumping trick....

....shouldn't you be able to jump the ground at the relay to the chassis to close the circuit and get your lights and gauges..?
Normally the circuit is closed to get power to the injectors, fuel pump etc...to get started. So once your running the relay opens at a set rpm to let power loose to the mfd and lights...correct...?
So if all you do is jump the ground, your just taking a little bit of juice away from the start up end of things....letting it flow to the lights before idle.....correct..?
Open all the time shouldn't hurt....?
Closed all the time would hurt since your not able to disperse the voltage hence the cooking of the ecu....?
Please correct me if I'm wrong, cause I'm goin' to McCall for the week and would really like to have some lights and gauges.
 
you have it a little back wards. the relay is a normally open relay. meaning no power goes through it when it is off.

after the sled starts the ecu grounds the relay turning it on and allowing power to pass through it.

so here it is: the chassis relay is the relay on the mag side engine brace.

terminals 85 and 30 the red wires to the relay are power in to the relay from the regulator.

relay terminal 87 red/white wire is power to chassis -- ie: mfd, lights accessories.

relay terminal 86 white/blue wire is the wire going to the ecu. the ecu grounds this wire when the engine starts. this turns on the relay alowing power from the 30 terminal red wire through to the 87 terminal -- red/white wire

so with the sled running do you have power to the 30 and 85 terminals -- red wires?

with sled running disconnect the relay and check for continuity to ground on the white blue wire. is there ground? if not ecu is bad if there is ground ecu is ok plug relay in with sled running is there power to the red 85 terminal on the relay?

if yes and you have ground the relay is bad.

if ya need more help ask we can get this tracked down.
 
forgot as far as jumping. if you have power to the red wire with sled running then you can jump the red wire to the red/white wire and you should have lights if not you have a broken wire or bad connection to the wires going to the hood.

you don't want to leave it like that. install a switch that you can throw after the sled starts
 
I gotta go put the fuel tank and stuff back on....I will be back.
I do remember from an earlier test that everything is functioning normally at the relay...
When looking at the wiring schematic and the relay itself...it doesn't look like it matches up on location with wires to posts...?
 
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