three wire temperature sensor wiring?

[whiteretta]

I had to do the three wire temperature sensor conversion when I installed my 3400, and I simply would like to verify I properly matched the right colors on the wires together, if anyone has their car close by and can tell me which wires they matched to what!

All help is appreciated!

[daguse5853z]

The wire colors are the same if you find a 96 and check the pigtail. let me draw up a diagram bc my cam has trouble in the low light and this is a common topic among GM forums.

[daguse5853z]

this is a rough copy (very rough, use ur imagination kiddies)
the top 2 wires are connected to the 2 wire sensor and the bottom wire is connected to the single wire sensor. This view is from the male, wiring harness end of things. Match the colors up. If your pigtail isnt coolant temp specific (GM used this shape plug on a few sensors) then just match the wires up to the correct positions.

[scd88ga]

MS PAINT? WINNING!

[daguse5853z]

ms paint FOR THE WIN!

[whiteretta]

Awesome, thanks bud!

[Z26_T]

so what cars come with the 3 wire ect sensor?

[heavywoody]

96+ cars with 3100/3400's. L-bodies had the 3 wire sensor in 96.

[3X00-Modified]

The funny part about this is when you go to a 3500 you almost wish you had kept the 2 individual sensors since now you have to drill and re-tap the cylinder head to fit the 3-wire. Stock 3500's are a 2 wire in the head and thats all, and the threads are way smaller than our 3-wire. Easy fix if you remember before you put the heads on, after that you need to get a sensor turned and re-threaded to fit if you want the 3-wire. As Geoff noted for my 96 thats what I had to do since its stock with one three wire sensor.

[heavywoody]

The 3 wire goes into the LIM on the 3400, is that hole not on the 3500 LIM?

[3X00-Modified]

Nope... lol

the stock sensor is in the side of the head.

[Z26_T]

i'll have to look again at my friends 06 malibu. I swear his 3500 had the ECT in the same location, but his was a 2 wire is why I had to ask .

So if you stick with two individual sensors, 2 wire ECT for the PCM goes in the cylinder head. Is there another hole for the single wire?

[cncguy]

IMO drilling and tapping the LIM for the second sensor is the best way to go. But if you don't want to pull the engine apart or have a way to drill and tap the hole, we offer a modified 3 pin sensor that screws directly into the head with no mods. Keeps installation simple.

http://britishcarconversions.com/compon ... gory_id=29

[whiteretta]

No second hole for a second wire on the 3400... but the Wells part number for the three wire sensor is TU178, and AutoZone stocks it, I finally found it again after a customer needed the part (temperature switch) for his 3100 '96 Grand Am, lol.

[13's or bust]

on my 3500 i bought the adapter, i havent had any problems with it so far...just having other problems lol. the adapter was on v6z24.com, it was from kcs direct, i have the part # if anyone needs it.