Howdy all, I need some help tracking down why my gauge cluster is acting funny. I'm curious if it's the IVR, because the problem itself is a bit of a doozy.
It's a long story, so here is the short of it. My 68 notchback (360/904) has been running 'hot' for the past month and a half, but it has never actually overheated. The temp needle loves to stay in the upper quarter of the gauge, sometimes pegging if you turn the car on after it is warm. Sometimes it settles down in the normal range, sometimes it doesn't. But regardless of what the gauge reads, the car has never had an actual meltdown (shutting off, spewing coolant, etc.). I'm trying to find out why.
To read the IVR voltage simply remove the wire from the water temp sensor, and read between the removed sensor
wire cap and chassis ground. Should read 5V, if it is a factory mechanical type regulator keep in mind it is a duty
cycle averaged 5vd.
The water pump was replaced two and a half years ago (admittedly with an el-cheapo unit), and the only mods to the cooling system is the flex-a-lite fan and absence of a shroud. The belt has enough tension and isn't slipping. Last summer, the car would do a strange thing where it would peg the gauge when It warmed up and then settle down in the normal range.
Today, as I was trying to pinpoint if it would ''overheat" at cruise or idle, the factory oil pressure gauge started to move around erratically, which caused me to scratch my head, as the factory oil pressure gauge has never read anything since I bought the car. This is because the previous owner installed a mechanical oil pressure gauge under the dash.
As for the fuel gauge, it never worked when I bought the car, and when I replaced the tank and sender, I never hooked it back up due to the reproduction sender stud not being long enough. I tried connecting it with alligator clips and whatnot, and couldn't get the gauge to read anything.
Apologies for the shaky/incomplete information, this temp gauge issue has plagued the car since I bought it and I wanted to give the full scoop. I know a bad IVR will knock out the oil, temp, and gas gauges, but I don't know if a failing one would cause the cluster to act like this, because the way the car is now leaves the possibility that all three gauge issues are completely separate and just happen to be rearing their heads at the same time. The biggest tip-off for me was the oil pressure gauge though, but I'm not certain. What are your thoughts?
