Making heater blow hotter?

[4wdEconoBox]

Ok, so I've got a few updates that might help. I cleaned all of the grounds I could think of, parked on a hill to see if any more air would come out (none came out btw). Now I've been sitting with the car idling for 20 minutes or more, and its still doing the same thing so I started messing with electronics in the car, if I turn the high beams on it raises the needle on the temp gauge some also. If I turn the fan on full blast with the cool-warm lever switched to warm it raises the needle some, while it's still raised I switched the cool-warm lever to cool and it drops the needle almost back to normal. Keep in mind I still don't have the heater control valve hooked up so that lever is only changing flaps and stuff under the dash... If I turn everything of the needle completely goes back to normal. It's sounding more and more like the gauge is just messed up, next step is finding a way to hook up that aftermarket gauge to get actual readings, I didn't have the right parts and the hardware store is closed today...

Edit: I know for a fact, it's either a bad ground or the sender for the gauge is messed up. I wired that digital gauge up to the stock sender (the gauge wasn't calibrated for that sender so it was reading 279-280) but it didn't matter all i needed to see was the last 2 numbers, to see if more electrical load made it fluctuate. I made it where I could see it from the drivers seat, when I turned on the heater it would jump up to 293 and settle at 287, when I turned the high beams on with the heater it jumped up to 293 and stayed there...I would say it's definitely an electronic problem now, I'm going to change the sender when the engine cools down and I'll let y'all know if it fixes it!

Edit:edit: So the plot f****** thickens... It's not the sender or the gauge. It has to be a bad ground somewhere, I have no idea where to check for it at though, at least I know it's not actually trying to run hot now though...

[Petros]

yes, sounds very likely a short or bad or shaky ground. The clue was that the temp gauge went up when you turn on the heater fan. kind of rare to have a gauge malfunction, if you rig up an auxiliary gauge, fully mechanical so it does not depend on the electrical system, you can safely drive it and not panic when you drive it. than you can take your time sorting out the problem.

I have a mechanical oil pressure gauge also independent of the electrical system. My oil light would occasionally flicker on, giving me a sudden panic. So I rigged the mechanical gauge and unplugged the oil light entirely, not even the sender is in place. funny thing is that oil light still occasionally flickers on and off, and I still get a sudden fright. A reflex when I see the oil light flash at me, even though I know it is not even connected to anything!

[4wdEconoBox]

That's exactly what I'm thinking too. It just didn't occur to me because of how slow these gauges react to quick change, ya know. On the stock gauge it looked like it was kind of creeping up in temp, when in reality it was an immediate jump up. I think I might another ground to the head coming straight off the battery. I might also clean up the ground points to for the alternator and the intake to firewall ground. I already cleaned the battery negative to chassis, all the grounds in the front, the bottom engine to chassis, and battery terminals. The only other two I can think of are the intake to firewall, and the battery negative to the alternator mount. Am I missing any? Should I move any of these around for better connection? Are there any I can add as an "upgrade" of sorts?

[4wdEconoBox]

I'm just gonna say this... I'm so lost right now... Cleaned up my grounds, then started the car, let it get to operating temp, than started checking all of my grounds with a digital multimeter and every one of them read the same with +/-.01 clearance... I did that with accessories off first, then I turned them on and checked. The temp gauge is still reading slightly higher with accessories powered on. It's not as bad as it was before I cleaned the grounds, but it still does it nevertheless. I'm wondering now if it could be my alternator not putting out enough amps to keep up? I don't have an amp meter, I've only got a digital multimeter right now...

[Petros]

easy alternator check without amp meter: with engine off check voltage across the battery terminals (should be about 12 to 13 volts), start engine and at high idle check voltage again across battery terminals, should be about 14 to 14.6 volts. If the voltage goes up after start up the alternator is working properly. If it goes above 15 volts, the voltage regulator may need to be replaced.

another even simpler test you do at night, with headlights pointed at a wall or garage door, turn them on with engine off, observe the brightness. Than start the engine, the lights should get noticeably brighter after start up and rev of the engine.

you might also spray some contact cleaner on the grounds, something that prevents corrosion like LPS-1 or CRC spray.

of course it is possible it is not any of the grounds, but some component is internally shorted. all you can do than is study the wire diagram and see if you can determine all of the components on the same circuit as the temp gauge (or that could affect it), and than systematically isolate each one in turn until the problem goes away.

[4wdEconoBox]

Ok well I think my alternator is fine then, because the lights get bright when I crank the car and brighten up some when I rev it up higher.

That's something else I meant to say I did, I put some of that battery terminal corrosion prevention stuff on all the grounds after I cleaned them up.

I guess that's my next step then, I'm about to start going through the fsm and checking stuff out, thank you!

[4wdEconoBox]

Well I looked at the wiring diagrams in the fsm for an hour or so last night and make sense of anything I was looking at, I think it shows the heater control and temp gauge on the same "c" circuit but I got confused haha. It's not a huge deal right now, it definitely isn't running no where near as high as it was and doesn't scare me at all anymore!!