i dont want to hyjack earthquakes thread so....

this may sound stuped, but if we were to connect to plug #230 (thats the one that the ecu sends all the info to the gauges right?) couldnt we use that signal to connect all the gauges? like and autometer fuel gauge and temp and oil pres , speedo rpm etc?

 

I'm far from an expert so don't take my word for it, but I'd think you would have to build something to convert the aggregate signal and break it out to individual gauges.

Theoretically, it would be possible, but I think it would be quite a bit of work.

 

whats an aggregate signal?

i thought that each wire on the white plug was an individual signal.
i haven't started hacking into mine yet, but i thought that was where the tach signal came from (one of those wires)?

i guess thats why i have always wondered why everyone uses aftermarket temp sending units and taps the block above the oil filter.

 

I was under the assumption that the data was carried on the same pins. If it's not, I apologize.
The reason that people may not use this connector is difficulty with calibration using aftermarket gauges. Most gauges will need to be used with their included sending unit to be calibrated properly. As a hypothetical example, a gauge may be looking for 0v to 5v input where as the stock sending unit may only be 0v to 1v output. Your gauge will display *something* but it won't be accurate.
I guess the my first question would be whether or not there a way to modify the output voltages of the stock gauge output pins from the PCM.

 

Hmm...I could be wrong too, but I thought that the blue and white plugs were INPUTS for the PCM. Not outputs. I think the only gauge output is for the oil pressure sender. The PCM sent the gauge signals through serial connections..possibly through the BCM for the gauges. But Im not an expert on it...I just remember what I messed with while I was doing wiring.

If you are going to use autometer gauges for everything, you are way better off just wiring it separately. They are just single wire senders for the most part. I just made my own little gauge harness so that I could remove/install the gauges easier.

J.

 

the blue one i know is for the serial data port, so its kinda an input and out for diagnostics. but i thought (and i could easily be wrong) that the white plug #230 either just plugged into the gauge cluster or a pigtail (off of the cluster) to send the signals to the gauges?

annd i guess it would be easier if your using after market gauges to have their own sending units, but hypothetically if the white plug has the signals and you could (in my dreams) get gauges that read a 0-5 v signal then you would have a lot less work! no?

 

See the issue is that some of the senders feed the PCM first. Like coolant temp and fuel level. The PCM gets these signals first. The data that goes to the cluster is serial data. It will be way more difficult to try to tap into all that than to just make a harness for your gauges.

For instance... one issue you will run into is finding a fuel level gauge. The fuel sender on an ls1 tank goes to the PCM... The PCM puts a voltage through the sender wire to check fuel level. If you try to hook an aftermarket gauge to the sender wire, it wont work, because the PCM and the fuel gauge will be trying to put voltage through it. You have to disconnect the fuel level wire from the PCM anyway... Besides, if you arent using a 4th gen fuel tank, you wont have a fuel level wire from the PCM anyway.

Coolant temp gauge is the same way. The PCM gets this data then sends it to the cluster.

Volt gauge is just simple. I mean you can pick up voltage from any place.

Oil presure never even enters the PCM. The PCM only uses the low oil level switch I believe.

But...see here is where I might be mistaken... Im not sure you can use any guage with those wires at the white plug. You might... I know you can pick up a tach signal, and the speedo signal from the 220 or 230 plug, and you can only use a programable speedo if you pick up the VSS signal here. Otherwise you need to tap right into the VSS on the trans. You might be able to pick up oil pressure and coolant temp. But I dont know what their value range would be...if its even usable by an aftermarket gauge.

Haha...but now its 2am and Im probably not thinking clearly...and Im babbling. I still just think that if you are going with all custom gauges, you should just dedicate a harness to them. But thats just my opinion, and the way I did it.

J.

P.S.... I know search is screwy...so you may or may not have seen this thread before. Its a good read. Some of it needs updated...but still some good info.

https://ls1tech.com/forums/wiring-stereo-electronics/445782-so-you-want-replace-your-cluster-aftermarket-gauges.html

 

thanks ghetto. i never found that thread before, makes sense now.