Could Weak Ground at Block Prevent Warning Light Op?

warmblood58 · Post by **warmblood58** » 24 Feb 2016, 23:56

Still struggling to get power at Fuel Pump (pump jumps fine) and Warning lights are not coming on in Position 2 (dash lights come on ) This car sat for 6 months. Strangely, yesterday, I forgot to attach ground at battery but blue wire was attached and I did get a few warning lights, so could this mean ground at engine block is at fault? How best to access these connections? I did replace fuses and bridged fuel pump relay. Thanks, gotta get this car (95 850 T5-r) running!

Post by **abscate** » 25 Feb 2016, 04:06

Bad grounds will cause all sorts of weird thing to happen. You must have had something attached to the negative side or else causality will be violated.

Post by **Ozark Lee** » 25 Feb 2016, 08:51

A DVM (DIgital Volt/Ohm Meter) is your friend in these cases. Although they are total junk, the $5.00 Harbor Freight special is better than guessing. For about $25.00 you can get a meter that is actually decent at places like Lowes or Home Depot.

...Lee

warmblood58 · Post by **warmblood58** » 25 Feb 2016, 09:11

I checked voltage at pump connection, nothing with key in pos 2 and relay removed with 15/87 pins bridged. The lack of warning lights have me stumped - I will check continuity when and where I can. Best way to access negative cable connection? Does it terminate near oil pressure sender. My car is pointed down hill unfortunately (vs a nice level driveway) and as it is a T5-r, access under the car is limited though I suppose I could jack it up in the front and carefully block and jack - don't usually work on cars that are not on level services.

Post by **abscate** » 25 Feb 2016, 09:20

The block attachment point is indeed near the sender if it is like my V70

Park and use the curb to scoot under.

warmblood58 · Post by **warmblood58** » 25 Feb 2016, 10:11

thanks, car not running so . . .