Author Topic: Fan stays on all the time...K1004V (Read 22847 times)

moynistan · « **on:** September 16, 2012, 07:15:25 PM »

By all the time, I mean whenever the key is in the on position. What would be the most likely cause? :confused:

Thanks for any help, this will be the first of several queries. I looked around for answers before posting. The Lieberry is an amazing resource, I am grateful.

Inge K. · « **Reply #1 on:** September 16, 2012, 07:29:03 PM »

Welcome Moynistan.

It could be that you have welded contacts at the relay, try to pull the relay...if you feel the relay click
when it leaves the socket....the relay is OK.
Otherwise try to give it a knock with a screwdriver handle.

Could also be that your water temp sensor or related wiring is shorted to ground, the bike should then be difficult to start when cold.

Inge K.

frankenduck · « **Reply #2 on:** September 16, 2012, 07:58:26 PM »

I vote bad temp sensor.

moynistan · « **Reply #3 on:** September 16, 2012, 08:26:47 PM »

Thanks for the responses. I believe the relay is OK. I swapped it out for the fuel pump relay, which definitely works, and no change...

Is there a way to test the coolant temp sensor without removing and putting it on the stove in a pot of water? :embarass:

The problem has progressed beyond this, but I wanted to address the earliest failure before going further into it:
The always on issue was "fixed" by a shop "tech" who turned the 4-way flashers switch into a fan switch. Now that has failed. Switch components all seem fine, as I hooked it back up to the flasher socket and they worked correctly.

My next plan is to run wires directly from the battery to the fan motor leads- Is there any risk in that, I don't want to fry myself or other components of the bike.

Thanks again.

moynistan · « **Reply #4 on:** September 16, 2012, 08:33:14 PM »

Quote from: moynistan on September 16, 2012, 08:26:47 PM

My next plan is to run wires directly from the battery to the fan motor leads-

As a test of the fan motor function of course...

frankenduck · « **Reply #5 on:** September 16, 2012, 08:40:35 PM »

No harm in hotwiring the fan but it will be of little use to you troubleshooting.

Here's some data points on the temp sensor resistance at various temps: http://www.motobrick.com/index.php/topic,327.0.html

Measure the resistance between pins 2 and 32 on the Mortronic connector.

The Motronic turns the fan on by grounding the blue/yellow wire from the Motronic to the fan relay. If the wire from the switch that was installed is grounding somewhere then that could be another possible cause.

moynistan · « **Reply #6 on:** September 17, 2012, 05:19:44 PM »

Fan motor is toast.
Planning to get a new Bosch motor from Beemer boneyard- anyone know if this is the same one as in the alternate parts list? Probably just going to replace the coolant temp sensor too since the bike is ripped apart...
Any link to a motronic pin diagram for this bike, or an easy way to find the right pins? Couldn't find any clues on the connector itself. Thanks.
Turns out my multimeter was junk, not to blame my tools or anything...got a new one this AM and much better success in testing :2thumbup:

Inge K. · « **Reply #7 on:** September 17, 2012, 05:47:44 PM »

Your fan stays on all time......................and your fan motor is toast? That`s kind of difficult.............

Or did something went wrong during the hotwire test period.............

To measure the temp sensor at a MA 2.1 equipped bike measure between contact 21 and 32 at the connector.

Inge K.

moynistan · « **Reply #8 on:** September 17, 2012, 07:36:10 PM »

Quote from: Inge K. on September 17, 2012, 05:47:44 PM

Your fan stays on all time......................and your fan motor is toast? That`s kind of difficult.............

:loco:
Right, sorry, that sounds dumb, but the fan on all the time issue was from the previous owner of the bike, as was the workaround. Recently the workaround failed, so I am digging deeper. It was an old problem and a new one rolled into one. I want the bike back to original functionality- automatic fan switch, and 4-way flasher at the dash. There you go, clear as mud. Thanks for the motronic info...

My multimeter didn't register any value (OL) for resistance. Power was off to the circuit, I measured 21 to 32 and 2 to 32 as frankenduck suggested. No love on either reading.

Inge K. · « **Reply #9 on:** September 17, 2012, 09:14:23 PM »

If you don`t measure any resistance between contact 21 and 32 in the Motronic connector (not the ECU itself),
You have an open circuit or a bad temp sensor.

BTW. Contact 2 is the output to the ignition module for coil 2/3.

moynistan · « **Reply #10 on:** September 17, 2012, 09:31:39 PM »

:hail: Thanks, yeah measured at the connector. I'll re-up the post in a week or so when I get parts and install...

frankenduck · « **Reply #11 on:** September 17, 2012, 10:11:30 PM »

Quote from: Inge K. on September 17, 2012, 09:14:23 PM

If you don`t measure any resistance between contact 21 and 32 in the Motronic connector (not the ECU itself),
You have an open circuit or a bad temp sensor.

BTW. Contact 2 is the output to the ignition module for coil 2/3.

Hmmm.... looked like a 2 on my SLP but you're right because I think there's a very faint 1 there next to it.

Inge K. · « **Reply #12 on:** September 18, 2012, 06:13:57 AM »

Time for new reading glasses. :giggles

Inge K.

moynistan · « **Reply #13 on:** October 09, 2012, 08:35:57 PM »

Any insights for a noob?
I thought I had this dicked. Not so much. :beatdeadhorse:

So far here's what I 've done:

Installed new fan motor and tested by powering direct from battery- pulling as it should
Added manual fan switch according to Lieberry instructions.
Can someone look at these photos and tell me what's going on?

cut L/Y under relay and pigtailed wire to open pole of switch
cut Br off of alarm harness and pigtailed "grounding" leg to other pole of switch.

Am I correct to think the alarm harness should provide a good ground?

Fan motor is connected via stock wiring harness now. Reading 12V at the connector.
When I power up the FAN STAYS ON ALL THE TIME.
When I jump out the fan motor brown wire to the to the negative battery terminal, the fan stays off on power up. The switch still doesn't work.

Is this telling me the brown to the fan motor in the harness is no good? It crimps together with like 20 other wires, but I have no other electrical issues at this time.

frankenduck · « **Reply #14 on:** October 09, 2012, 08:59:52 PM »

If you cut (instead of tapping into) the blue/yellow wire then you should not have 12V to the yellow/violet wire - unless the relay is stuck closed.

moynistan · « **Reply #15 on:** October 09, 2012, 09:42:40 PM »

How does one tap into a wire without cutting it, i saw you recommended against scotch-lok type connectors. I tried to show what I did in the pictures. I cut the wire & pigtailed a new one in with the cut ends and crimped it. Is this not "tapping into" the blue/yellow?

Thanks for your patience

frankenduck · « **Reply #16 on:** October 09, 2012, 10:02:37 PM »

Sorry but "pigtailed" can different things to different people.

That last pic lets me know that you did tap into the Blu/Yel wire.

If the fan is still coming on then there's one of four causes (in order of what I think the probable cause is):

1) Your temp sensor is failing.

2) The wiring from the temp sensor wiring has chafed and is grounding, telling the Moronic that the engine is very hot.

3) The Moronic has failed and grounds the Blu/Yel wire when it shouldn't.

4) Your fan relay is stuck in the closed position.

I'd troubleshoot #4 first though because its easiest. Disconnect it from the Blu/Yel that comes into it and see if the fan runs or not.

moynistan · « **Reply #17 on:** October 10, 2012, 02:53:47 PM »

With the relay pulled, and the switch wiring as described, no fan, so the relay is junk? How easy is it to toast one of these, could it have resulted from a poor wiring decision on my part? I never heard any frizzle or saw/smelled smoke. Do they burn out like a fuse?

moynistan · « **Reply #18 on:** October 10, 2012, 03:59:34 PM »

So with a relay in and measuring VDC between violet/yellow, and brown at the fan motor connector, I have 12V. This is further indication that the relay is toast?

frankenduck · « **Reply #19 on:** October 10, 2012, 04:10:16 PM »

Test for continuity between the red terminals on the relay when it's unplugged. That should be an open circuit. Or a closed circuit if you put 12V across the black terminals.

Inge K. · « **Reply #20 on:** October 10, 2012, 04:14:55 PM »

With the relay out of the bike, measure between 30 and 87, if you got a open connection..the relay is OK.
Then it receives a incorrect signal...at 85...which is the coil ground from the Motronic unit.
As long you measure ground at 85 in the relay socket the fan would run.

Inge K.

moynistan · « **Reply #21 on:** October 10, 2012, 10:04:07 PM »

Looks as though the relay is good...so this means the blue yellow is grounding on its own somewhere? Does it mean anything that when I jump the brown wire from the fan motor straight to the battery negative terminal that the problem goes away? You see the limits I am working with :loopy:

Inge K. · « **Reply #22 on:** October 11, 2012, 10:43:09 AM »

Remove the relay and measure if you got ground at 85 (blue/yellow) in the socket with ignition on.

And if, disconnect the Motronic unit...if you then measure open circuit...check the sensor circuit for short to ground.
If disconnecting the Motronic don`t change anything, check your switch wiring...and the wiring between the relay and Motronic.

Inge K.

moynistan · « **Reply #23 on:** October 11, 2012, 03:23:49 PM »

I just realized I did my whole switch test and mock-up with the Motronic disconnected.
disconnected I'm reading resistance OL at 85. Is this same as open circuit?
connected reads 6.2M ohms... Is this a ground? just not a good one, or good enough to trip the relay?

With the relay in the fan stays on even when the coolant temp sensor is disconnected- does that mean anything, or change where to look?

With Motronic disconnected and the relay in, my manual switch is functional and the fan stays off. So...its faulty temp sensor wiring, or wiring to the motronic? I have continuity on both wires from temp sensor to motronic connector.

frankenduck · « **Reply #24 on:** October 11, 2012, 04:27:00 PM »

Test if the terminal for the blue/yellow wire is grounded by using a voltmeter and putting the other lead to 12V.

If that is grounded with the Moronic unplugged then you have a problem(short to ground) in the wiring between the Moronic and the relay.

News:

Author Topic: Fan stays on all the time...K1004V (Read 22847 times)