I have a 1987 Volvo 240 that I am currently working on. One of the problems I am having is that every time I start the car fuse number 12 blows. It is an 8 amp fuse that is connected to the back-up lamps, A/C relay, power windows relay, and the rear demist relay. I tested a larger fuse in their to see if it works and it does but I want to get down to what is causing the problem. I am assuming is is the A/C that is giving me the problem. I know the A/C relay is in the center console but I have not had the time to check it yet. My question is what is the best way to go about narrowing down the problem? Check every relay connected to fuse 12, if so how do I test it? Any help will be greatly appreciated, Thanks again.

 

Do you have a wagon? Does it blow as you start it or when you back out of the parking lot. Instantaneous pop or a few seconds? For instance, if you turn the rotary **** for the a/c all the way to the right until it absolutely won't turn, the a/c is off. The demist should default to off. Ditto windows. If all is off and it blows as you start it, tougher to narrow down but a dead short to be sure. Obviously if you place the car in reverse and then it blows...there's a problem with a. the neutral safety switch b. the bulb connectors or c. if it's a wagon, broken wiring in the hinges. And other stuff I can't think of at the moment but others will chip in.

 

It is a sedan. The problem is that it blows as soon as I turn the key to try and start the car. The A/C is off as well, which is what I believe it is because occasionally there will be a deep rumbling noise coming from what sounds like the A/C air vents. The problem could be caused by a short in a wire. The question is, do I check/test the relay or should I just start looking for shorts. Thanks for the help.

 

I believe I have figured it out. I found some frayed wires going from the A/C condenser to a in-line fuse. One of the wires continues to the A/C compressor and the other goes into the firewall. I am not sure what these are called but I definitely need to replace them. I was going to make my own but I am unsure that I can because of the connections to the in line fuses. Any suggestions would be appreciated. Thanks for you help.

 

Just buy a new fuse holder and fuse...wire it in.

 

I pulled out the wires going from the A/C condenser and replaced them. Before this the number 12 fuse was pulling up to 12 amps and it is only a 8 amp fuse. Replaced the wires now it is only pulling about .5 amps. Works perfect, Thanks!!

 

hey skateandneverdie, it sounds as if I am having the exact same problem as you, even my AC rumbles. I was hoping you'd be able to tell me a little more about what you did to solve it assuming you remember?