Our 85 which was previously an Auto has been converted to a 5 speed and we also swapped the Gauge Cluster to that of an SR5. We currently have all gauges working minus the oil pressure, we checked the gauge and sender per the FSM and all seems within spec. Our Oil Pressure sender is placed at the front most plug not close to the oil filter. Is this the reason for the non-functioning gauge, I can't find anything for placement of the sender. Any help is appreciated.

Have you ever accidentally plugged it into the old dummy light switch or accidentally grounded it out?

Not that we know of, but would that not show up as an open across the oil and ign terminals on the cluster, we are getting the 44Ohms the FSM calls for.

What would happen is the heated element gets bent from too much travel. When the needle hits the top peg hard, it bends the element down, and the gauge reads 0 forever (since at true zero it wants to point straight down, but the bottom peg stops it at zero).

You mean this would happen if you short it out (IE - use the dummy gauge)?
If you short it, it goes up to the H position. Don't short it. I did it, but I did it through a bulb, so I was limiting current and wanted to check the gauge.
Mine measures 44ohms also.
I just switched in a sr5 gauge cluster.
I replaced the sender with one from a local auto store.
Problem is, most auto stores (and toyota) show 2 different senders for the SR5. The sender seems to work (resistance changes with oil pressure), but I can't get it to work with the gauge. I just orded another sender from NAPA (another $45) - no refunds on these parts, so it's a bit of a bummer.

If you didn't switch the sender you may have shorted the gauge. If you're still reading 44 ohms, that's a good indication that you didn't short it, but don't press your luck. If you want to check it, make sure you go through a bulb of some type to limit current. From what I've read some shorted gauges survive just fine, some do not.

Basically: you need the correct SR5 sender. I haven't found anyone that can tell me which of the 2 possible senders you should use. FSM only mentions one method of testing it (using a test light or bulb) - FSM mentions that the bulb should FLASH (faster for more oil pressure) which makes no sense to me if the sender functions as a variable resistor.


email me directly, I'm sorting this out too: d_ginther@hotmail.com

The reference of two different sending units for use with the oil pressure gauge is due to the fact that two different companies were supplying Toyota. Denso type and Yazaki type. Trick to figuring which one is needed is to look at the wiring harness of the donor vehicle...it'll say Yazaki at various places along the harness covering. Same applies to OEM plug wires....multiple suppliers for the factory.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />

We tried 2 different senders (both used)but still no go. So are u saying that the Gauge and the sender need to be brand specific to function? I am thinking the Auto and Manual Wiring harnesses are different, reason is that we had to move a couple pins around to get the fuel gauge going, this being the case we may have unknowingly shorted the gauge.

I'm saying there are two brands (aftermarket).
There are also two part number per toyota for the SR5 variety. I do not know what the differences are. If it was just brand, I'm not sure why Toyota would have two different part numbers.

Unsure of auto/manual differences. FSM doesn't show any differences for testing the clusters between auto and manual, but does for SR5/non-SR5. I didn't actually double check the wiring diagram. I did plug an automatic gauge set into my manual, the only thing that didn't work was the tach.. Not sure if that was wiring related or the tach was bad.


Try shorting the wire that goes to the sending unit through a small 12v bulb for a second. The gauge should jump. That way you've got good connectivity. After that... I dunno - you're in the same boat as me. I was trying to find a listing of ~ resistance at idle for the SR5 sending unit, but have not located one. The FSM indicates that a bulb grounded through the sending unit with 12V should FLASH... Which doesn't make a lot of sense if it's resistance based.

We just checked our continuity,from sender to cluster connection and our pin out does not match the FSM. From reading on this issue it seems that there was some variances from harness to harness this could have occured at the different manufacturing plants. We are now in the process of tracing the wire that was in that slot.

So no continuity from that PIN to the connector in the engine bay? Interesting.. Mine definitely had continuity, as using a lightbulb would manipulate the gauge.