huntintales

For some reason my computer port under my steering column was not registering anything, at least thats what the guy at the part store said when he hooked up the handheld computer to it. I then proceeded to check my fuses in the fuse box with my light tester. There are several fuse ports that have no power to them, an these fuses are good in these ports. The funny thing is there is no problem with the truck that these fuse port pertain to. Most of the ports are turn signals and trailer lights and a few others. But for some reason there is no power at these ports. I kind of feel like this is somehow tied to why my computer port is not working...Anyone got any clues here..
Thanks

EinST

Welcome to the forum. Year, model, trim level and exact list of fuses would be helpful in figuring out what the common denominator may be.

huntintales

my truck is 2003 silverado 2500HD with 8.1 liter - Allison Trans.

Thanks

EinST

Check the OBD data link connector for battery voltage on pin 16 (rightmost pin, bottom row as you view the connector under the dash) and ground on pin 5 (5th pin from the left, top row). If battery voltage absent, check the 15A CIG LTR fuse. As for the unspecified fuses, some are on a switched circuit. They'll show voltage with key in ACC, RUN, or START, depending.

huntintales

I went a tested the fuses again with the key in all three modes, acc, run,start and the same few fuses still have no power. I have identified the fuses and they are marked as follows. Although I dont know what they exactly are, but here is what the owners manual has them as. (VEH STOP), (VEH CHMSL), (LT TRLT/ST TRN) , (RT TRLR/ST TRN), ( LT TRN, RT TRN)

I appreciate your replies..

Blane

EinST

All six fuses sit between the Turn Signal/Flasher module and respective bulbs. It makes sense that their normal state would be no voltage. Are you still having an issue with the OBD datalink port?

MDTAHOE

Those fuses would have power when you turn on turn signals or step on brake etc...

huntintales

you are right...fuses work when activate, but obd still has no power????

EinST

No power where? No battery voltage on pin 16 or the CIG LTR fuse?