Guest D. McHenry Posted November 3, 2008 Posted November 3, 2008 OK, so I am wrapping up the last bits and pieces of my dash/gauges swap and am struggling with the temp gauge. It has always read erratic since we did the engine swap. It read hot on the freeways and then seemed to cool at idle. Then there was the turn signal thing. When you would signal for a turn, the arm on the temp gauge would tick back and forth in time with the signal. Now I've got a brand new gauge. Same crap. Runs really hot. Signal thing still happens. ANd when you turn on the lights or the fan the gauge goes up 10-15 degrees. I replaced the sending unit. No help. I grounded the back of the dash pod, near the temp unit. It got better but not totally. Gonna throw on a reliable mechanical gauge to make sure the temps really aren't as high as they say. But I'm not sure what else to check electrical wise. Headlight ground? I did notice the pod was painted where that ground attaches. Maybe thats causing it?
monte70car Posted November 3, 2008 Posted November 3, 2008 d. the amp gauge is showing a discharge which means the alt. aint charging the battery. when you replaced the sending unit did you get one for the gauge package??? also did you put anything on the threads of the sending unit?
DavidTX Posted November 3, 2008 Posted November 3, 2008 I had a similar problem and it was the ground. As Robert said and my instructions stated not to put any teflon tape on the sending unit.
Guest D. McHenry Posted November 15, 2008 Posted November 15, 2008 Well I've solved some mysteries, but the temp gauge is still not working. First off, someone HAD put some sealant on the temp sending unit. I removed it and cleaned all that stuff off. Then I ran some new grounds to the gauge housing and that seemed to take care of the weird changes to the temp when I turned on the fan, turn signals. So now the reading is nice and consistent. Problem is its constantly too hot. The gauge normally reads right at 210. I put on a solid mechanical temp gauge I've got and it shows the normal temp is actually 180. So now I am stumped again. One other weird thing. The Amp gauge tends to swing towards the positive when I turn ON various items. Is that normal? I am wondering if it is wired backwards.
monte70car Posted November 15, 2008 Posted November 15, 2008 amp is going the wrong way if its positive when you are turning items on. is the sending unit new or a old one??? also what type of motor is this? also have you checked the pcb on the back of the cluster? the factory gauge will read higher as its in the head by the headers. i take it you put the mechanical temp gauge in the intake by the water neck? if so that is why one is reading higher then the other. always remember the head area is going to be hotter when it comes to water temp.
Ian Posted November 15, 2008 Posted November 15, 2008 Amps will go positive when you turn things on, it is more current draw. A volt gauge would go negative when you turn things on as you have less volts available... Ian
502ci Posted November 15, 2008 Posted November 15, 2008 Amps will go positive when you turn things on, it is more current draw. A volt gauge would go negative when you turn things on as you have less volts available... Ian I agree...it is working correctly. Bill
Sam (Bones) Posted November 15, 2008 Posted November 15, 2008 Originally Posted By: Ian Amps will go positive when you turn things on, it is more current draw. A volt gauge would go negative when you turn things on as you have less volts available... Ian I agree...it is working correctly. Bill I agree too, a amp gauge reads the amount of amperage being drawn, so the more you turn on, more amperage being used
monte70car Posted November 15, 2008 Posted November 15, 2008 i guess my amp gauge then is backwards as it goes to the neg side when i turn items on. then when its idling it goes to the pos. side. if nothing is on it show stay in the middle pointing stright up.
monte70car Posted November 16, 2008 Posted November 16, 2008 alt is working. i guess it would have help if i said when the car aint running it goes to the discharge side running its either stright up or to the charge side.
Big Jim Posted November 16, 2008 Posted November 16, 2008 Do you have the resistor on the back of your Temp Gauge?
Guest D. McHenry Posted November 17, 2008 Posted November 17, 2008 Thanks for the info on the amp gauge! Thats one less thing to worry about. As for the temp gauge: I dropped in a GM crate 350 a while back. I am using a new part store sending unit. The gauge is part of a repro gauge package I picked up recently. There is NOT a resistor on the back of the temp gauge. I checked my old unit and there wasn't any resistor there either. My Monte is a 72, not sure if that makes a difference. When I tested the mechanical gauge I installed it in the same place as the electrical. So this isn't an issue of one being on a hotter spot than the other. My next step will be to put the old sending unit on to see if the prob is the new unit (switched units when I was having ground problems.) I will say this, I am getting TIRED of draining the dang radiator and removing the upper hose just to change this thing. Thanks for the help guys.
Guest D. McHenry Posted November 17, 2008 Posted November 17, 2008 Holy cow. I pulled the old gauge cluster out of storage and what do you know, there are resistors on the temp AND fuel gauge. (My stock pod came WITH gauges.) So I guess I should put BOTH of them on the new pod? I just realized that the fuel gauge was reading way past the full level. So maybe it's reading high too. What a "no duh" moment.
Guest D. McHenry Posted November 17, 2008 Posted November 17, 2008 OK, maybe it wasn't a "duh" moment. Installed the resistors that were on the fuel and temp gauges. Now the gauges immediately spike all the way to the right. Very strange.
Big Jim Posted November 17, 2008 Posted November 17, 2008 I would put the fuel gauge resistor on the temperature gauge only and see how it works. Of course the instrctuins were for the transition from idiot lights to gauges. I still have issues with my fuel gauge. It only goes to 3/4 but does read correctly back to E. My Temp gauge works fine now. We did use the temp sending unit that came with Sonny's kit as well.
monte70car Posted November 17, 2008 Posted November 17, 2008 the stock gauges has a resistor on the fuel and water temp. the one on the fuel gauge runs left to right and the water runs up and down. the pcb sits on top of the resistor.
kc8oye Posted November 18, 2008 Posted November 18, 2008 this is exactly why I left my stock idiot lights in place, and mounted AutoMeter gauges elsewhere :>
Guest D. McHenry Posted November 24, 2008 Posted November 24, 2008 Well I can't seem to figger this out. The gauge runs right around 210-220 no matter what I do. I've ruled out running hot, ground, resistor and sending unit probs. I think maybe the gauge just isnt calibrated right for my car. One thing I did notice is that the fuel gauge is also reading high. Maybe its something with the printed circuit I got. I had to replace the one that came with the unit. Anyway they are at least consistent, so I'm just gonna move on and finish the rest of the dash. If they bother me enough, I'll come back to em. THanks for the help guys!
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