Synced carbs, now temp gage not working

[Lumpy Rider]

Hi all! Have been recovering from health stuff, job stuff and rebuilding life. In the meantime, "Ruby" has been collecting dust in need of TLC. I am now back in the saddle! I pulled the air box to sync the carbs (sorely needed) and make other repairs. She runs grrrreat! One problem is a non functioning temp gage. Any ideas what I may have overlooked during reassembly to cause this problem? Your ideas could save me some time. Hopefully, I do not have to pull the air box again. Ugh. Thanks!

[Jimvoyager01]

A lot of voyagers have a poor ground on the temp gauge,,,

[Lumpy Rider]

Gage worked before I pulled the air box. I must have disturbed the link between engine and gage. Any ideas where I should start to find the culprit?

[ekap1200]

Gage worked before I pulled the air box. I must have disturbed the link between engine and gage. Any ideas where I should start to find the culprit?

Check the ground wire , remove the battery and batt-tray. you will see the ground wire plug which came from the neg battery post cable.

[ohiojack]

My gauge didn't work when i bought my 1200, it was simple, the wire fell off the sending unit. You'll have to pull the battery, the battery tray and the thermostat housing is right there. Check the wire going to the sending unit. Mine was laying on top of the head. ohiojack

[Lumpy Rider]

Thanks ohiojack. I think I spotted the thermostat housing under the right side of the battery tray.

[Lumpy Rider]

Wiring to sending unit looks good as does ground wire from the thermostat housing to negative battery post. Fuses good too.

[ekap1200]

Wiring to sending unit looks good as does ground wire from the thermostat housing to negative battery post. Fuses good too.

That wire that goes to the temp sender , has a bullet connection under the inner right side cowl. i don't know how pulling the air box could have pulled it apart but do be aware there is another connection. Hope you find your issue with it.
If you are going to ground the sender wire to see the gauge needle move , do not hold it to ground, but a second. It can damage the very fine wire in the coil movement.
oh you also said you pulled the air box, and had made other repairs. What or where else were you working on ?

[Lumpy Rider]

Thanks for the help. I will look for the bulleted end of the wire to the sending unit and check it. While I had the battery and air box out I replaced the no. 2 spark plug boot as the hard plastic original was shattered and terminal broken and the positive battery cable as it had disintegrated into gray dust under its insulation. I also found just laying on top of the valve cover a cover holding a damaged coil spring that fell of off what I would call a junction box for the throttle cable...just under the left side of the battery tray. The positive cable I replaced with a fashioned automotive style one with the battery out of the bike.

[Lumpy Rider]

No luck getting the temp gage operational again. Needle twitches when you move ground wire off and on negative battery terminal, but that's all it does. Replaced the wire, making sure it has solid connection...no luck. Electrical troubleshooting has never been my strong suit.

[Draxxis]

I looked at mine because my temp gauge stopped working too. But I don't see a wire on the thermostat or a loose wore near the ground terminal. Any suggestions?

[Lumpy Rider]

I read in the service manual that the temp gage is wired directly to the battery. Look for this. Still not sure what the issue with my gage is. Retraced all wiring a third time and everything seems in order.

[triton28]

Draxxis;
the wire from the temperature sensor is really hard to see/get to. The sensor is located at the bottom of the thermostat housing below the RH cylinder head coolant pipe leading to the housing, and below the 1/2" coolant bypass hose from the thermostat housing to the bottom of the radiator. One would have to remove the battery and plastic tray and look carefully to see the brass tip of the sensor.
Dave

[Lumpy Rider]

Problem solved Connector on temp sending unit looked good and was tight, but pulled it off and found the inside of it caked with white powder. Replaced connector and cleaned up the sending unit. Presto!

[ekap1200]

[Draxxis]

Ok, so I took the battery and holder out of the bike, still didn't see a wire anywhere. When I looked to the right side of the battery, on the frame, attached to the battery overflow hose holder, I found two wires that I am assuming are ground wires to something. Not exactly sure what they go to. So I took them off, cleaned them up as well as the frame to make sure I was getting a strong connection. Reconnected everything and still nothing. Tonight, I will be taking it all apart for another try. But this time I am also going to disassemble the right side fairing as well to see if I can get a closer look inside. Maybe that bullet connector, someone previously mentioned, is my culprit. At least I am hoping it is.

The only wires going to the negative terminal of my battery is the main negative and the negative side of my trickle charger.

[Lumpy Rider]

Draxxis-If everything looks in order and you haven't already done this, pull off the connector that attaches to the lead on the sending unit and clean, reattach and crimp it slightly so you know it fits tight on the sending unit. I found that mine was caked with crud inside, probably from battery leakage. Replaced the connector and...presto...issue solved! It's hard to get at, but I was able to pull off the connector with my right pas by standing on the right side of the bike. I reattached it using long nosed needle nose pliers. I also place a penlight down there for illumination.

[triton28]

The wire from the temperature sensor goes from the tip of the sensor, (female connector, Yellow/White wire colour ), and heads to the RH side of the bike to the main wiring harness around the amplifier/cruise control activator area behind the upper cowling, unfortunately. Look for a single Yellow/White wire coming out from the main harness having a female connector.
The single Y/W wire lead from the sensor to the harness is not a long wire, maybe a foot long at most.
It is also hard to distinguish the colours when they get aged and dirtied by time.
Dave
I just noticed you have an '86 so forget about any reference to Cruise control, but it is around the amp area.

[Draxxis]

Would it be alright if I disconnect the temp controller, add a longer wire (same gauge) to the current and a new bullet end? Or would the length of wire affect the reading?

Also, what did you use to clean the temp controller after removing it??

[triton28]

The length of wire will not adversely affect the reading.
Steel wool, brasso, silvo or any good abrasive polish will clean the terminal.
Dave