84 4X4 SR5 temp gauge problem

MY84SR5

MEMBER
1984 TOYOTA PICKUP

The truck is a 1984 SR5, 4 x 4 truck with a 22R engine. My temperature gauge will sometimes work and sometimes not. It will move up into reading the temperature then suddenly drop like the engines off then go up then drop. It's gotten worse and worse over time. Now it will hardly read, just stays down. One mechanic checked and said I need a new gauge. Do I have to replace the whole instrument cluster?

Monday, October 8th, 2007 AT 3:09 PM

3 Replies

MERLIN2021

MECHANIC
17,250 POSTS

Before we take such a drastic step, lets try the temp sending switch!

It's in the coolant flange, on the right side of the block!

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Monday, October 8th, 2007 AT 3:56 PM

LJSTOY

MEMBER
6 POSTS

Yep. The temp sending unit is on the pass. Side on the intake by the thermostat. 84 didn't have very complicated wiring so I would follow the wire as far as possible to check for any loose connections. I went ahead and got an aftermarket gauge because I didn't trust the (it's either hot or it's cold) factory gauge. I wanted to know how hot is hot after rebuilding one motor already.

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Thursday, October 11th, 2007 AT 12:22 PM

MY84SR5

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3 POSTS

I had a new sending unit installed and the gauge worked fine for about 1 mile then went into the flipping mode again. The mechanic said the old sending unit had a short. He said if it still has the same problem it's the gauge. If it's the wire that's a problem because it's taped into a bundle with other wires.

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Monday, October 15th, 2007 AT 12:59 PM