three wire temperature sensor wiring?

[Z26_T]

I'd be interested if you'd pm it. I fear that the "3400" that was swapped into my car is actually just a 3100 with a 3400 UIM. *shrug* either way i'm leaning towards a complete 3500 swap instead of just the heads/lim.

[Outlaw1846]

i'm actually glad to see this post because i'm on the verge of doing the swap myself and could really use the help on this particular topic, i have a 92 gt 3.1 that the motor lost compression so i took it as the chance to drop the 2000 3400 i got my hand on into. i think i've got it all figured out EXCPET for this temp sensor thing that the 3x00 guide talks about, but it makes no sense to me.? would some care to explain it better for me please?

[Z26_T]

So our cars have 2 CTS (coolant temp sensor). We have a 2 wire "CTS" sensor near the thermostat, and a 1 wire on the back head. The 2 wire is for the ECM (Engine control module) and the 1 wire is for the gauge inside the car. If you use a 3 wire "CTS" sensor, you have can wire the ECM and gauge off the same sensor. I believe some heads don't have a spot for the 1 wire "CTS" sensor, thus the need for using 3 wire is there. I also believe that some lower intakes have a different thread pitch and the 3 wire CTS fits instead of the 2 wire.

I could be way mistaken on everything stated above.

[Z26_T]

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

My "3400" has 2 wire and the single wire.. is it possible that I have a 3100 with just the 3400 uim?

[heavywoody]

Did you install the engine?

Is your engine bay painted all flat black by chance?

[3X00-Modified]

Yes that is the car you are thinking of Geoff... its the Tog 3400 5-speed 95 that was on cardomain for a long time.

It is possible to have a 2 wire and 1 wire sensor on a 3400, all you have to do is drill and tap the head for the 1 wire sensor. I just did this for Roberts 3500 top end. I'm using the stock 3500 two wire sensor and adding in his 1 wire for the dash read out.

This one.

http://www.cardomain.com/ride/531359/19 ... et-beretta

I love how those install photos show the headers with an automatic still in it. Never posted photos of the 5-speed swap done, and with those wires hanging under the dash I would not want to buy that car... talk about electrical nightmare.

[heavywoody]

Jon, you need to get out of my head lol

That's exactly the car I was thinking of. I'm fairly certain he used a complete 3400, but then again, that car was a basket-case back in the day.

[3X00-Modified]

yeah but like I said, its very easy to drill that 1 wire sensor hole... I just did one, and back when they started doing 3400's that may have been the alternative solution rather than rewiring the harness since they didn't know as much as they know now. That car was my inspiration to get the damn S&S headers to fit, I wanted to be the first one in the active community with headers in my car that fit perfect, granted the TOG ones were done REALLY nice, but were the same deal as mine, modified Grand Am headers... That's where I got the idea to just cut the S&S ones. Roberts Milzy headers are friken awesome but I can't see those fitting the auto like the TOG ones did. I wish there was still a GA alternative out there to make fit.

[Z26_T]

That's exactly the car I was thinking of. I'm fairly certain he used a complete 3400, but then again, that car was a basket-case back in the day.

Haha. That's putting it nicely... (and it still is a basket case). You have no idea what i've gone through with this car.. That's why I ask a lot of off the wall questions because my car was mutilated. The dash harness isn't quite as bad as it looks... I just did a dash swap and was looking into swapping the harness also, but it wasn't needed. The majority of the hacking I've fixed with shrink wrap butt connectors. Everything which he did splice he used the house twist style... The worst of the worst is the engine bay. The headers fit okay. He beat the bulkhead to nothing and hacked out pieces of it to get the down pipe to fit. I still had to bend it back more so the o2 sensor would stop hitting.. I imagine all of this is because of him doing the manual swap after having the headers fitted for the auto. There were a few wires melted to the down pipe which I had to rewire and reroute. Yeah, I can talk about it all day... It has been my DD for the past year with only a few issues. But all in all, I wanted a 94-96 Z26 with a 3400 manual and got it. Just got a lot more than what I was expecting too. If I get it the way I want it before giving up on it, hopefully, I could get a super trophy at bfest for what I've had to do..

[heavywoody]

If I get it the way I want it before giving up on it, hopefully, I could get a super trophy at bfest for what I've had to do..

I'll vote for it lol... some of us know/remember that car and what was claimed by the previous owner. It's nice to see someone tackle someone elses "project" and right it.

[3X00-Modified]

"The basket case recovery" award? lol, might have to talk to Mike about that one.

[Z26_T]

"The basket case recovery" award? lol, might have to talk to Mike about that one.

I like it! lol. Don't think there is much I can do about the engine bay being spray bombed though. That is without spending a crazy amount of time..

[woody90gtz]

It's nice to see someone tackle someone elses "project" and right it.

Been there. Done that. haha

You could also just move the temp sensor from the head to the engine block. That's what I did for my 3400. I got 2 bad 3-wire CTS in a row from the parts store.

[heavywoody]

Aircraft strip the engine bay! Hahaha... sorry. Just having a little fun at the previous owners expense.

[Z26_T]

Apparently there are some good stories about my car... haha. I'm tempted to start a thread where all the stories can be posted.