Thread: How much can bad grounds screw up?

On my long drive today, I pondered how three different gauges (OEM temp, VDO temp, and VDO oil pressure) could all possibly be messing up at the same time, in the same way. The two VDO's share a power source, but ground via two different wires to two different spots. The OEM temp is all on its own. Most of the time, the gauges work properly (OEM gauge in the middle, VDO temp at around 190, VDO oil pressure around 35psi), but when one messes up (i.e. VDO temp needle beyond 250), they all mess up. I figured there must be something wrong with the ground of the car, since they are all grounded in different places.
Also, despite a complete cleaning of the IACV AAC and a checking of vacuum lines, my car will sometimes stall as I come to a stop. And I don't think my radiator fans are turning on.
The last piece just happened. I shut the car off, but it wouldn't start again. No starter whine, just a click from behind the dash. I fiddled with three grounds: One near fuse box on pass side of engine bay, one next to the coolant overflow, and one on the driver's side strut tower. And then it started up. So I clearly have a grounding issue I need to sort out.

Question is, how many of these issues might be caused by grounds that need cleaning?

Lots of issues, just think, with out a ground path there will not be any voltage going to anything since electrons need a complete path. I would upgrade all of your grounds. Go buy some 8AWG or 4AWG and start replacing/upgrading the grounds.

Grounds are important. I clean them every time I'm under the hood doing stuff. A little conductive grease doesn't hurt either.

I would say all of those could be cause. Diff car but on my jeep just one of the grounds was badly corroded(driving fast through puddles :P) and it would stall after starting, Power windows would sometimes not work, parking lights and dash lights would turn on when pressing the break pedal, not start, radio problems etc etc. Clean the ground and boom. Works great.

im with ben conductive grease and cleaning them every now and again is VERY important you can run into alot of issues with bad grounds

Pls don't use dielectric grease between connections. Dielectric means: it doesn't conduct.

Make sure you have good connections, then coat them with dielectric compound to protect them from further corrosion.

also clean surfaces for your ground connections both on the chassis and the ground wire or cable itsself is really important