Temperature and Fuel Gauge woes

Wiring, lights, heater controls, anything electrical..
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12Valve
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State: ND

Temperature and Fuel Gauge woes

Post by 12Valve »

Months after putting in my fuel sending unit from a Valiant, (against your guys best wishes) I'm having issues with the temp gauge and fuel gauge working right 75 miles before the needle moves off Full. You can tell me you told me so.

This weekend I was chasing down what I thought was over heating issues.

It started on Friday when I was driving on a county road 55 MPH the temp gauge started to climb to the upper limit of the white arch, it then proceeded to exceed past that to the hot range. I pull over to let the truck cool. No immediate signs of over heating, no coolant blowing out, no steam, not a single thing.

I limp the truck over to O'Rielly's to by a temp gauge built into the radiator cap, as well as order a new water pump, thermostat 160 degree. I drive the truck back to my garage with the Temp gauge pegged at HOT. I hop out and check the gauge under the hood, its running at 175 degrees. So to me that's not too hot my Cummins runs 180, and my Hudson runs 165 all day long.

The next day I pull the thermostat off to replace it thinking that it could have been bad, but lo and behold there's no thermostat. The PO was a complete hack. I'll get to that later.

I throw the thermostat in and replace the water pump. Take the truck for a test drive and the gauge still maxes out. Check inside the coolant cap trucks running 170 degrees. So today I head to the junk yard and take a temp sensor off of a 64' swepty with a slant 6. But the temp sensor is too small. I am not 100 percent sure but I think the PO may have drilled an tapped the housing so that it could accept a mechanical gauge temp sensor. Or is this a different styled gauge? Tomorrow I'll be heading to the yard again to pull a temp gauge and a fuel sending unit from the same truck, would this possibly correct my issue? I don't think it is a ground or resistor issue, due to the gauges will read different from each other.

Now to rant about the PO. The temp switch inside the cab to make the truck hot in the winter was missing so the heat was always on... I pull the heater core to install a choke cable so I could turn the heat off, the PO cut the bottom of the Model 85 with a can opener and removed the control. I'll be picking up an entire unit tomorrow to hack apart, and get the control out of it.

Sorry for the long text post, any help will be appreciated.

712edf
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Re: Temperature and Fuel Gauge woes

Post by 712edf »

I think it is a grounding issue with the temp gauge. Next time it does it, unplug at the sensor. If gauge still pegs HOT then the wire is shorting to ground. If it drops while unhooked then either it really is hot or the sensor is bad.

Bucky
1966 W500
1975 W600
1978 W200 club cab

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Hobcobble
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Re: Temperature and Fuel Gauge woes

Post by Hobcobble »

What year is your Sweptline? Have you grounded the
fuel sending wire to see if the gauge pegs to full?

John

12Valve
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Re: Temperature and Fuel Gauge woes

Post by 12Valve »

The gauge was operating as it should, however something was wrong with it. I replaced it with one I pulled out of a 64' and now the temp gauge stays right in the middle when I'm driving, if in traffic it creeps up.

At the junk yard I got a brand new (no varnish, shiny metal) fuel sending unit, the float had a hole it in but the fuel sending unit from the one I had had the same float so I used that one, temp gauge, gas gauge, entire heater core, lower dash controls for the heater, blower and defrost, choke cable one with the C on it, light switch that works, and a nice glove box with no rips tears, or water damage. All for the low price of 40 bucks for everything.

The truck is a 63' by the way. I figured I should just throw a bunch of parts at it for next to no money. But the nice thing is I finally have a ball valve to shut my heater off so when its 80 degrees outside the cabin isn't being heated by the coolant circulating through it

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