garretthes

I'm trying to get my 1959 truck temp gauge to work with the 2004 LM7 transplant. I replaced the engine coolant sensor with the 3 wire version from the 98 LS series. I connected wire "C" to the old temp gauge. I ran one side of the temp gauge to a hot wire off the ignition. The gauge never moves at all.
Stumped. (I tried reversing the wires at the gauge)

Pocket

iTrader: (22)

Is the old gauge still functional?

The 3 wire version is rather simple...

oange ss

iTrader: (50)

did you ground it ? sender maybe 5v signal since it's PCM driven

garretthes

After driving the truck for a while I noticed the gauge move. It just doesn't move very much. Evidently idling for 15 minutes didn't warm it enough to see the change. I'm thinking this gauge may have done the same thing with the original engine. So all is working....except the gauge is probably not registering correctly.

garys 68

iTrader: (1)

Probably doesnt function in the same resistance range. Here's my solution:
I put the 68 vette temp sender (1/2 NPT) in the block plug of my LS motor. It wouldn't fit the small head bosses. I'm also using the 68 gauge. It's reading higher temps than the head, determined by aftermarket gauge and IR temp gun. Could be because of the location close to the headers.
The LS computer reads the temp from the drivers side front sensor. On the 98 camaro, a computer/gauge sensor combo is used. The rest of the years get gauge temp from the computer.
I want to keep the 68 gauge. So the data on the gauge resistance is below, so is my solution.

I got the following temp info for the 68 gauge from Willcox on CF.
temp/resistance
220/70
200/90
180/115
160/140
120/250
100/340
I measured the 98 camaro LS sensor below:
temp/resistance
192/215
181/272
157/428
135/675
105/1225
In addition, I've got an aftermarget (harbor freight) gauge sensor that's calibrated as follows:
http://www.harborfreight.com/cpi/cta...emnumber=98481
temp/resistance
260/70
200/140
185/210
165/280
150/350

A 250 ohm resistor in parallel with the harbor freight sensor gives nearly identical values to the original vette sensor. I used the adapter from these guys:
http://www.speedwaymotors.com/LS1-Wa...pter,8195.html
The HF sensor bound up on the adapter so I use a 1/8 NPT male/male and female/female to space it out.

garretthes

Update
I recently had my cooling fan relay die which caused the engine to overheat a bit. I was sitting in traffic at the time and had the scan tool plugged in. At the hottest it registered 250 degrees. The analog gauge registered at around 80% at the same time so it works great.