93toy

This is on an 85 4runner, but I knew I'd get more 22re traffic here.

Here's the deal. I can go fire it up right now and the temp gauge will go halfway up (even though it's cold). Then at any given time while driving (no pattern) it will go all the way down and bottom out. Then later it will be back to halfway again. So I'm thinking it can't just be a loose connection, because why would it come halfway up when cold? Maybe a bad sending unit?

So today I finally located the sending unit (I think). Between the 2nd and 3rd runners on the intake mounted vertically right. From my searching on here I think that's the one. But here's the kicker, if that is it, there's no wire connected to it at all?! What gives? How does it EVER move?

Any help or thoughts? Can anyone tell me what color the wire is that should connect to it? Where does it come through the firewall so I can back-track it? The wiring schematics in the Haynes manual don't help much. Anyone?

BigBluePile

iTrader: (3)

Ah, well, there should be one wire that clips on to it. Since you said gauge then the sender should be a bell(like at a hotel to ring the desk) just forward of the oil filter, but aft of the engine mount on the passenger side. You need to reconnect the wire. It's probably just hanging around...so to speak. The connector itself just slides onto the nipple on the sender. Make sense?

Flash319

That is the one. They work off resistance. So if the wire is sort of touching the block or any metal you will get the "half way" position. Find the wire and hook it back up. It is in a bundle of wires that runs down the fender towards the starter. That bundle runs up to the main harness that runs through the firewall where the ECU is.

93toy

Okay guys, so basically I need to find that &#%@^ing WIRE! (Haha!) But that does explain why the gauge jumps around. Thank you for explaining how to trace the wire from the firewall. That's what will help the most.

If anyone has anymore input throw it at me.

93toy

Just to make sure I'm clear, BigBluePile - have I located the correct sending unit that I need (between intake runners)? Because from the way you describe it, it sounds like it's lower and forward. Just want to make sure I'm right.

BigBluePile

iTrader: (3)

Actually it's belowish the oil filter, that's a rubber boot that covers the sender:





I got the photo from Trophs thread:
https://www.yotatech.com/forums/f131...arness-136647/

93toy

10-4! Thanks a million!

abecedarian

On the 22R/RE/RTE, the coolant temp sender to the gauge is on TOP of the intake manifold between the #2 and #3 runners (and below it is the pipe to the heater core)... behind the thermostat. The plug for it could be anywhere within 7" radius or so, but should be in the harness that goes to the VSV's on top of the intake manifold, or at least taped with the plug to the cold start injector.

If you're looking around below the intake manifold for the plug, you're most likely looking in the wrong place.

BigBluePile

iTrader: (3)

I think I have oil on the brain. You were asking for the temp gauge and, well I'm an idiot. Abe's right, it's up on top aft of the thermo housing. That wire couldn't have gone far. Its the same kinda connector thats in that pic I posted earlier. Way sorry for the confusion.

Try this:


Via:
https://www.yotatech.com/forums/f116...t-work-103953/

abecedarian

well shat the bed... I thought the thing was either green or white and here you have a brown one?

but yeah, that's it. I'm thinking that connector just above and to the right of the sender is the one that goes to it (the other one to the right, appears to go with the plug at about 5:00).

abecedarian

now you're all confusing me.... blue, brown, white, green, above, below... I'm getting vertigo.

BigBluePile

iTrader: (3)

We're talking about the fuel guage right?

my-4x4

I had same problem, on 22r where would that plug be? (replaced dummy light cluster w/ sr5)

BigBluePile

iTrader: (3)

which plug? Whether it's the oil(on passenger side of block) or the temp(on top on the intake, aft of the thermostate housing), IIRC, both senders are in the same spot. As for the fuel gauge...I have no idea where that guy is coming from...

abecedarian

coolant temp (dash gauge) is on top of the intake manifold, between 2 & 3 cylinders
oil pressure (idiot light or sr5 cluster) is on the side of the block, in front of the oil filter
no where near the same spot.

93toy

I think I've got it now, thanks everyone! Now if I can just find the wire I'm set.