Electrical Monster!!!!

[RMertens]

I've got a 90 that I have just done a whole boat load of things to. From installing an intercooler to different transmission and rear end. Basically what I am saying is that besides the body and interior everything has either been rebuilt or replaced or removed!!! First off when driving under throttle everyting seems fine. When I come to a spot sign or light, the oil pressure light comes on and the gauge bottoms out. Bring the RPM up past idle and it comes back to normal. Also, when I'm driving the speedo will jump all over the place at times and then at times read right. Also, put two Derale radiator fans in place of the factory fan and when I switch them both on my gauges read high!! My pyro, speedo, and water temp. Do I need to put more grounds on it, or does not having some of the plugs not plugged in because of factory items removed matter??? Give me a hand!!! Thanks!!!

 

[Grizzly]

Sounds like a grounding problem or maybe you need new gauges.

 

[PBJ2500CTD]

Or, your power source is shared on wire(s) that will not carry the load and when the fans switch on the circuit is unable to supply the required current/voltage.
I would 1st follow Grizzly's suggestion and check the grounds. They should be separate, not grouped through one wire.

 

[RMertens]

Thanks Grizzly I'll plan on putting more grounds on the ol girl!!!

 

[RMertens]

Thanks Bruce, after doing some more looking and staring and thinking about the whole thing, I beleive your right also, I definately need more grounds and I think I should re-wire some things and put them by themselves instead of somewhat together so they don't share power!!! Thanks I appreciate it!!!