my coolant temperature gauge is pegged, and its been that way ever since i installed the new manifold two weeks ago. ive been getting the trouble code 15 for the past week now, and ive bought a new sensor on the thermo housing, checked the wire that mounts to the block between the first and third cylinders and i cant get it to stop pegging. my question is, where can i check to fix this? any grounds? im not sure if it matters, but my fan still kicks on and off on its own.

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1987 LG4 Camaro z28

Performance
KN airfilter, flowmaster 80 series and catco high flow converter, 180* thermostat, edelbrock performer intake

System
Panasonic CQ-DF200U deck, fosgate speakers (hpc1369, frc2246), fosgate 400a4 amp

 

the one wire sender in the driver's side head does the gauge.

the two wire sensor in the waterneck does the computer.
and the one wire switch on the pass side head does the fan switch

take the one wire senderon the driver's side, and unplug it. turn the ignitioin on and see if the gauge moves. if no, take the wire and ground it... see if the gaugne moves... if no the gauge is bad.

the code 15 if I remember is a CTS curcuit problem. that's the two wire sesnor in the water neck.. one yellow one blac, i think.
make sure it's plugged all the way in


if the fan's running normally dont' bug with the one on the pass head.


Edit. check to see you haven't pinched any wires or forgot to put the ground on the front somewhere as well.

[This message has been edited by Pony Killer (edited October 11, 2001).]

 

I am having the exact same problem. I just got this 1983 Z28 and it's hard a hard life. It's a 305 with a Rochester quadrajet. Whoever took the smog stuff off just cut wires all over the place and I'm not sure what wire goes where. I got the oil pressure gauge to work by changing the sensor/switch. The temp gauge stays pegged. The sensor on the thermostat flange was busted and another that looks like the same kind is mounted just to the right (driver's side) on the intake manifold. No wires are attached to either of them but they take a single wire. A sensor on the driver's side under the exhaust manifold has a wire attached but it doesn't seem to matter what I do with the wire, the gauge doesn't budge. Maybe a bad gauge. The dark green wire to that sensor on the block makes a tiny blue spark when I ground it. This motor doesn't have an electric fan so I don't know why I have all those sensors.

 

geez they just stripped the smog stuff off of the car, thats terrible. the thermostat housing holds the thermal vacuum sensor, which has two nipples and one of them goes to the front of the carb and the other goes to the efe valve. anyways, i think i may have damaged the gauge when i started my car with the distributor in wrong. how would i go about replacing the gauge? how expensive is this?

 

My temp gauge was pegged because the needle was rubbing against the edge of the
gauge. That's all it was. I feel kinda stupid that it was that simple but I haven't had
this very long. I just took the plates off that cover the gauges and bent the edge that
it was sticking against down with needlenose pliers. Now, perfect!