1995 Blazer Electrical Problem

You don't want to check for continuity, you want to check for a short. Look for bare or chafed wires in the running lights circuit. Also check the trailer harness. Electrical problems can be VERY hard to find.

Brian,

I'm assuming this is an intermittent problem? Here is about the only easy way to find it. First, get a wiring diagram. Our local library has then so I assume yours does too. Then divide the circuit into branches. Sounds hard, but it's not. You may be lucky and find the factory splice, or you may have to isolate them as best you can. Then install inline fuses in the separate branches and see what blows. I find most shorts in wiring someone added, not what the factory put in. Make sure you use small fuses in the inline holders, like 3 or 5 Amp. I've done electrical work for years and "intermittents" are never fun.

If it instantly blows the fuse, it's a lot easier to find.

Let me know if I can help.

Al

I have seen corrosion on the inside of trailer hitch socket(on your truck side) cause very similar problem to what you describe. The only other thing I can think of is aftermarket item (CD changer etc) where mounting screw grazed a wiring harness. > I find most shorts in wiring someone added, not what the factory put in < 99% of time, very true.....Rico