Project car almost complete...am hoping I can get some assistance with wiring up the gauges. I read through several threads on this topic, but looking for a simplified version here..."Gauge Cluster 101." I have this nice "cluster connector" diagram below and am looking for physically what to connect to them and from where (i.e.: purple wire from fuel sending unit to "C2, connector #4", white wire from ECU red pin #10 for tach to "C1, connector #7"). FYI, those are just made up examples and may be completely wrong. I have a '91 RS with an LS1 swap using a Pain(ful)less wiring harness, 4L60E trans., and 4th gen rear. I am of course most interested in the speedo, tach, oil pressure, fuel level, temp gauge, but would prefer to have them all if someone has such a guide. Again, not only do I need to know what wire (color, etc.) but where is originates (ECU, engine bay, etc.). Thank you in advance!

 

The gauges all get their signal from the corresponding sending units. They are all in the engine bay and travel through the c100 connector and then to the dash/gauge connectors. The engine harness is completely separate. When I wired up my gauges I used the stock wires and removed the connectors for the original gauge cluster. I changed the ends on the wires for the sending units and mounted a 16 pin duesch wire connector to my pre wired gauge cluster. So basically the whole cluster is wired to one connector. It's easy to remove when necessary. All the gauge lights/dimmer controls work like normal. Same w the indicator/directionals. My speedo is independent of the ecm. IDK about newer cars.

 

Thank you @Firechicken82. Appreciate your pix and detail. Here is my issue: I bought this about-to-be-junked V6 RS for just a few hundred dollars. It was in incredibly bad shape and the wiring was a nightmare. It does have the C100 connector, but see my image below to know what I am dealing with. All of those wires are cut & taped off. That said, any help you or anyone can provide regarding what goes where would be greatly appreciated!

 

I wired mine from the same basic diagram you have. Most of the wires in it pass through the c100. Just use the colors as a reference. Inside and in the engine compartment are the same color. There are also c100 pinouts/schematics. It's just gonna come down to finding a good resource for the pin out. There is a bunch of threads on the pin outs of that connector. There are also people here who know the pin out by heart! I'm sure they'll comment.

 

This should help:

Click this link and select the C100 schematics for the 91 Camaro,...... https://berlinetta.info/C100.htm

Click this link and select the C207 schematics for the 91 Camaro,..... https://berlinetta.info/C207.htm

 

Thank you again @Firechicken82 and thank you as well @John in RI. So the gauge wiring is new to me. I believe my gage cluster is correctly wired from the cluster connectors to the C100. That said, I would just have to route the wires (shown in my post #3) to their correct home, correct? If so, that is what I need help with. For example, where would the wire for the fuel gauge splice into? Oil pressure goes into sensor at rear top of LS? My coolant sensor does NOT have a wire. Again, I am most interested in the speedo, tach, oil pressure, fuel level, & temp gauge, but would prefer to have them all if someone has such a guide. So if someone can provide how each wire is routed from the cluster connector to its ending location, that would help me a lot! Thank you in advance!

 

Assuming you are using stock gages, sorry if I missed that, but everything except tach and speedo will tie directly into the sensors they are connected through. Your fuel gage is independent of the LS swap, and even if you had an aftermarket gage (and assuming its Ohm'd the same) it would tie directly to the fuel sending unit. You can adapt 3rd gen sensors into the LS for the stock gages and use LS specific sensors that the ECM needs (water temp), etc). The stickies at the top of the LS swap forum go into greater detail.

 

Thanks @ShiftyCapone. And yes, stock 3rd gen gauges if I left that off. I will check it out this weekend and may come back with a few questions. Thx for the support!

 

Yeah, the LS ecm really only cares about coolant temp. You can tap existing sensors into oil pressure etc. For instance, I run two coolant temp sensors. One for ecm, one for gage. There are a couple ways to do the tach, output from ecm, or an output signal from the coils (auto meter).

 

Thanks @ShiftyCapone. Happen to have a part # for the 2nd ECT gauge that you added to just run 1 wire to the gauge cluser temp gauge?

 

If you are using an aftermarket gage it will typically come with a sending unit, or recommend a compatible unit, with a single wire that you run to the gage. I run the OEM style sending unit for the ECM in the driver side head and the gage sending unit in the passenger side head. I "think" you can also tap into the ECM outputs to see what temps the ECM is looking at if you are using an OEM gage.

Forgot to mention, with stock gages you can use the stock coolant sending unit and run it just like stock.

 

@ShiftyCapone I have the 2-wire OEM ECT sensor, but that is 1 wire ground and other is sending wire for ECU. I can try to tap into that as your suggest. However, I was looking for the part # of the ECT with the single wire (& the pigtail) that you used for your gauge. I am using the stock 1991 3rd gen gage cluster.

 

Keep that one for the ECM. Just use your stock coolant gage sender and put it in the other cylinder head. That ties to F5 on the C100 which is a dark green wire to the sending unit.

 

@ShiftyCapone What I'm saying is that I do not have the stock coolant gage sender. That's why I am looking for a part # for that sensor and pigtail. I only have the LS 2-wire ECM sensor already in driver side head. I need another sensor (that I can put in the passenger side head) to hook up to F5/C100, but need the part #s please

 

I'm sorry, I misread your question. Something like a standard products TS76T will work. I think the stock unit is like 1305 ohms at 190 deg and 55 ohms at 260 deg. Anything in that range should work.

 

@ShiftyCapone Thank you. I looked up the thread on the TS76T and it is 3/8 Inch-18. I believe the LS1 head port for the sensors use a 12x1.5mm thread, so I'll have to keep looking...unless you(or someone) know of a snder with that thread. Thx!

 

You may be able to buy an adapter. See what the stickies say at the top of this forum.

 

I did find this at Summit: https://www.summitracing.com/search/...ord=cin-sn12mm

...as well as this on Amazon: which may work if the sender wire will give same result hooked directly up to the gauge and then ground (or not) the other wire...