Temp Sender Dumb Question

[BROKEN-ONE]

on the temp sender there is only suposed to have one dark green wire right ? but what if you has two ? can you just use one ? what if you tried to hook one up and it did not work ? i have had other trucks and not come across this before . any insight to this would be great .

 

[sarasotausmc]

My 87 Jimmy with a 350 TBI only has the one green wire. I can only answer for mine. It may help if you give some info on your rig.

 

[BROKEN-ONE]

info

81 gmc , 350 , sm465 , 208 tc .

 

[ryoken]

You've lost me... The sender has 2 posts? There are 2 wires?

If its a 2 prong sender, ones a ground, the other is a send.. shouldn't matter which is which... jumper one to a grd and hook the green to the other..

But it certainly sounds like it has the wrong sender in there...

 

[dyeager535]

Thats a switch for an idiot light, not a gauge. Either that or the ECM oil pressure switch off of a later truck.

 

[BROKEN-ONE]

idiot light

so if the wires to the truck are for a light , how do you make a gauge work . i have taped both the dark green wires and i can get the gauge needle to shake , so i think the gauge is ok . this truck has been hillbillied together , and know i am trying to fix all the gauges . also i have tried just using one wire but that did not work . i have searched around here but only found a few issues cloes to mine , but not the two dark green wires .

 

[BROKEN-ONE]

sender

oh and the sender is one prong . sorry . any help for this would be great .

 

[dyeager535]

You at least need to find the right temp sender. All the GM temp senders are the same, EXCEPT the actual body of the sender. They are either "large" or "small" depending on the heads they were installed on. It's only the threads themselves that are different, but just letting you know there are two varieties.

I'd pick one up at a wrecking yard, (I'm cheap and they don't fail often) then test either of the green wires with it to see if they work as is. I suspect one of them should, but if it's been hillbillied together, who knows how the wiring to the cluster is.

Edited for temp instead of oil pressure.

 

[BROKEN-ONE]

temp

the wires an gauge i am talking about are for the temp sending unit . the oil pressure ,and volt gauge are the only ones i have working so far . i think there maybe a two prong sender i need that goes in the head , one for a light and a gauge ? the haynes an chilton book have me mad ...

 

[dyeager535]

Oh sorry, I was thinking along the right lines, just wrote the wrong piece. Corrected.

Anyways, no, a temp gauge is a one wire deal. There are only three temp senders (barring the large/small issue) and they are idiot light, gauge, and ECM coolant temp. That's it. Two wires for each BUT the gauge sender, which is ALWAYS one wire.

 

[BROKEN-ONE]

wire , wire

i can make both wires shake the temp gauge in the truck , one at a time . i have tried tying them both together . with no luck . this is driving me crazy . i hate wiring problems .

 

[BROKEN-ONE]

the sender

i have come acrossed the restance thing before , when i took a motor out of a ta and put it in an other truck , the restance in the sender was not right and the gauge would not even come close to where it was supoosed to be .

 

[dyeager535]

My suspicion then is that the cluster is simply not wired correctly for a gauge. It's normal for that to be the case, especially since thats the way GM handled it.

I say pull the cluster, trace the two wires you've got to the cluster connector, pick one of those wires, and use that to "run" the gauge. You will likely have to move the wire from one position on the cluster connector to another, but you can de-pin the connector/terminal with a paperclip.

Should be hooked up like the fuel tank gauge, if that will help guide you a bit better.

 

[BROKEN-ONE]

thank you

thank you that is what i thought , just wanted an extra mind or two for the help . boy i love wiring .