I need to install an aftermarket temp guage in my 89 TBI. The sender does not disconnect from the wire. Does anyone know an easy route to get the sensor through the fire wall, for example is there a big enough grommet ? I would hate to drill a big hole and hit something behind the firewall.

 

Just cut the wire and solder it back together. Then you only need a hole the size of the wire.

 

Are you sure it is a wire? May be a capilary tube. Cut that, and you've junked the gauge. I have NEVER seen a electric gauge that didn't disconnect from the wire.

 

The instructions say that the sendor does not disconnect from the wire/tube and gauge. I think there is some type of gas inside of the black tubing that controls the temp. I think I will mount the sendor onto a thermostat housing with a plug, and just route the sender through a pre-existing grommet (hopefully). This may be wishfull thinking because I only have 6ft to play with. I will probably have to shop around for a 12 ft one to get proper routing.

 

I did a search and found out that the guage is actually a mechanical analog guage. That is why it does not detach. I have no idea why, but the Autometer package it came in called it an electrical water temperature guage. Attached is a photo from someone else's site, but it is the same guage.

http://www.rx7turboturbo.com/robrobi...temp_gauge.htm

 

Yup, cutting that would have been the end of that gauge. Six feet should be plenty, I've always had to much left over, and ended up with a wad of that tube since it is too long. Getting it routed is the only hard part. A place to start looking might be where the vacuum lines run thru the firewall.

 

Definatly dont cut the "wire". Its a tube filled with gas that is calibrated to the gauge. All mechanical gauges have this cappilary tube that takes pressure/temp measurements without bringing harmful fluids into the passenger compartment.
Worst case scenerio you may have to drill a hole in the firewall. Just make sure if you do you use a gromet on the hole. Last thing you want is a false reading on the gague because the firewall rubbed a hole in the capillary tube.

 

Pull the carpet back from the floor behind the brake pedal. See if that grommet is big enough to fish it through.

 

I searched and finally found an electric setup. Only needed enough room to run (3) 18 guage wires. I mounted the sender on the thermostat housing.

 

How? You got any pics of that. I have a guage to install but do not want to mess anything up. So, if you got any info of how to set up the sender in the thermo housing would be great/
Thanks.

 

Go to any local auto store and tell them you want a thermostat housing with sender holes. Mine was $8 at O'reily's. It came with 2 holes and a plug. I bought the electric guage from Autometer. It was around $40. There are three wires. One to the sender, one to the fuse box and one is a ground. I used 18 guage wire. It took me 45 minutes to hook it up. The guage also has lights on it. Also easy, just a power and ground wire. Power wire goes to the headlight fuse. My only problem is finding somewhere to put the guage. I don't smoke so I am thinking of putting it where the ash tray is located. I have seen that on the forum before. if everythign is not clear, just hit me back and I will try and get photos downloaded. Once you buy the guage and the housing for the thermostat you will see that it is almost impossible to screw up

 

Thanks, just ask for thermostat sender unit housing, right.
I will try that.
How are your readings, and how much do the differ from the original guage?
Do you still have the original going??

 

Yes, just ask for the thermostat housing with sender holes.
The original guage is still in tack but it does not read correctly. I think I may have a ground problem but did not want to trace it. The labor was way less by just installing the new guage. The readings are right on the money. I operate no higher than 220 degrees. The guage will rise to 220 and stay there. My guage has color codes along with the numbers. At 220 there is a green mark. I never cross the green mark. I have not ran hot, so I guess it is accurate.