Bouncing gauges

[hd1shrk]

OK, i fixed my issue with the speedometer and gauges when my positive cable grounded against the manifold. Soon after I started noticing that my truck, 1992 Sierra, 305 with auto trans, was running only about 160. Now I know running cool is better than running hot. So I changed the thermastat and coolant. It still runs cool. If you watch the gauge it will eventually climb to operating temp but, drops as soon as it gets there. Also I have noticed since then that my oil pressure gauge is fluctuating between 15 and 35 psi.

When I changed the thermastat i broke the ground conection on the housing taking it off. So, I put a new end on it when putting it back together. It didn't help. I even put an end on each of them thinking it wasn't getting a good enough connection. Still didn't help. The truck seems to run rough too. Check engine light comes on and off intermittantly now too. Did i fry some sensors when i shorted the system out? Maybe even the computer? If it is the temp sensor(s), there appears to be two. The one on the side of the head, and the one at the front of the intake manifold. is the oil sending unit at the back of the motor still or have they moved it since i had my 76 chevy?

Any ideas are greatly appreciated.

Thanks

[BernieB]

Well, you probably didn't do your alternator any good when that positive cable cooked. I suspect that might be the source of your problem now. Check your ground cable too.

[hd1shrk]

According to the gauge the alternator seems fine. Should I have some one check it out make sure it is okay? I didn't take any chances when I cooked the positive cable. I replace the ground cable at the same time. Mostly because the positive was sitting in the ground cable when it melted.

I just used a standard wire end with a 3/8 hole for the ground at the water neck. Do i need to use and end that is closer to the original?

Thanks!

[bubbatrucklover]

It doesn't hurt to go into an autoparts store and have your charging system checked for free.

Did you double check all the appropriate fuses and trace the wires down by where you grounded out to the sending units and then to the firewall?

[hd1shrk]

OK, if its not one thing its another. Took it to the shop to see if they could make heads or tails of the problem. They told me the computer was reading the correct things, just not showing correct on the gauges. Bad gauges and you need to buy a new dash or just put in some aftermarket. And the engine light was caused by the EGR valve. So I was going to get a new one and install myself, no big deal. Went out to go get the part and when I got in my truck the battery was dead. All the lights were off when it was parked the night before. Jump started it and went to the store. Took a bit to start but it ran. Came home to put on the EGR valve. Disconnected the battery, then some of the connections to the throttle body. Took off the EGR to replace it. Its different than the new one. Supposed to be a number in the directions that tell you which spacer/washer to use, there are several different sizes. My EGR number wasn't in the list. So I clean my old one up and put it back on. It was being held open by chunks of carbon. As I touched the negative cable to the battery I hear a click. Look around to find that the A/C clutch was engaging. Made sure the all was turned off. Still the clutch is locking in. Unplugged the low pressure swith to disengage the clutch. Is my short in the dash, anyone ever have this problem? If its not one thing its another. Now the truck seems to load up, hard to start and seems to idle like ****. Runs ok when driving down the road. Any ideas where to start looking?

Thanks

[bradrhale]

Originally Posted by hd1shrk

Supposed to be a number in the directions that tell you which spacer/washer to use, there are several different sizes. My EGR number wasn't in the list. So I clean my old one up and put it back on. It was being held open by chunks of carbon.

Leo, i told you there was washers and spacers underneath these things.

i always used the same size that was originally in there. might try cleaning out your old one before getting the new one dirty. the old one might still be good.
your hard start might be partly related to your AC clutch. extra power is needed to spin that clutch which makes starting the truck harder to do. be careful about how many trips you make in this truck as this added extra will be difficult on the starter. do this, disconnect the AC clutch and see if it is any easier to start.

[hd1shrk]

Originally Posted by bradrhale

Leo, i told you there was washers and spacers underneath these things.

i always used the same size that was originally in there.

Actually the original was designed different. It does not have a "washer" under it, it has more of "nipple" that sets in the intake. Only aftermarkets have the washers. Anyone have heater control switch go bad? How do you check them? What are some of the symptoms? My a/c clutch is/was engaged constantly even with the a/c turned off.

[Ninja_Lawn_Guy]

I'm still having issues with my fuel guage, says empty one minute, half tank the next. I "assume" that the float maybe is not straight into the tank and maybe is touching the sides or something, cause everything else is workin.

[crabtruck]

Kind of also sounds the way a rubbing hot short on sender would.


PS: brad/mud/bernie/etc - leave that alone.

[BernieB]

Could also be a bad contact in the ignition switch.