Board Logo

Head Temp Sender
Jo Mama - January 2nd, 2003 at 07:25 PM

I've been trying to install a vdo head temp sender and have almost given up. The sender is under spark plug No.3 and has 2 wires coming out of it one white and one red. I'm assuming one is the sender and the other a earth wire. My problem is that temp gauge needle darts to the far right as soon as its gets some power. Im sure the gauge is earthed and ive switched both wires around on the sender with the same results. Would anyone know what my problem may be? Does the needle darting off to right indicating anything?

Thanks for any help,

Nick.

[Edited on 2-1-2003 by Jo Mama]


Andy - January 3rd, 2003 at 02:19 AM

Nick,
I just installed mine yesturday. The thermocouple (under No. 3 spark plug) has a 2 pin plug on the end which plugs into one end of the loom of wire supplied in the kit (I'm assuming you bought the kit?) The other end simply attaches to the gauge, no other connections (power or earth) are need, except for the light.
http://www.bus-boys.com/bbvdo.htm#temphead 
Andy


Tnate - January 4th, 2003 at 01:51 PM

Sounds to me as if one or more of the wires is not connected. It could be that the gauge works on negative reistance, so when there is no signal, it goes to the right. Same get up as a pressure gauge.

Hope this helps,
Tnate


Jo Mama - January 4th, 2003 at 02:05 PM

Andy you're right. The sender that I bought (seperately) has the white, two wire plug on the end. I don't have the rest of the components apart from the temp gauge.

Thanks, that explains a lot.

Does anyone know of any other head temp gauges and senders? The gauge I have just says "Temp" without "oil" or "cylinder head" written on it. What is this gauge for then?

Thanks,

Nick.


mnsKmobi - January 6th, 2003 at 09:09 AM

Sounds like you've got the wrong gauge. The temp range should give you a clue. Oil temp is from 100 - 250 F, CHT is 100 - 600 F.


Che Castro - January 6th, 2003 at 09:11 AM

how much does the kit cost in oz?


Andy - January 6th, 2003 at 03:43 PM

Jo Mama, as mnsKmobi said, the temp range on the gauge you have will give you some indication as what it is.
Just remember, the VDO gauge has to come with it's own loom of wire, and the gauge is calibrated with that loom. You cannot shorten or lengthen the loom without afftecting the reading!!!!

Che Castro, I paid $137 for the complete kit here in Brissy, not sure if that's good or bad though.
Andy


OvalGlen - January 6th, 2003 at 09:21 PM

Just to Emphasise what has been said,
"White goes to white.
Red goes to red.
"No Wires are connected to ground"
No wires are connected to 12 Volts.

The exception to this is the Night time illumination - cant remember how the globe is connected on this particular guage.
-
Could you please tell me how well this
guage works when connected at spark plug.
I am waiting to dissmantle engine to connect mine to head bolt.


Andy - January 6th, 2003 at 09:49 PM

Glen, I too would have prefered another loacation for the sender, but the two obvious ones, exhaust bolt and head bolt are both torqed up tight, and from looking at the sender, I'm not sure they will cope with the pressure. It's probably easier on the sender being under the spark plug despite it will be in and out on a regular basis.
I've also been lead to believe that it's the most accurate location for the sender (I suppose the head bolts will see a lot more cooling air).
Mind you, I have found it a pain when installing/removing the plug, though it may be a little easier on a type 1 motor.
Andy