fuse box power

[datboibrad]

ok i just recently put my sr into a 91 shell and now i dont get any power to the interior fuse box. fuel poump comes on and the gauge cluster works but the headlights, windows, and radio wont come on. none of the interior fuse box fuses show power. any ideas?

[bb4_96]

did you get a hacked up harness? Loose connection?

[g6civcx]

Okay, let's start tracing through the power flow. Can you start the engine up?

1) Is the battery hooked up correctly? Are the terminals making good contact? Is the battery sufficiently charged? Is your alternator working correctly? Is your voltage regulator in good shape? Check both high and low voltage output (sometimes people will only check the low; too much is also not good).

2) Are you getting power to the number 1 relay box? It's located between the battery and the passenger-side strut tower. It's in that area. Check every single fuse and also check out the fusible link in that box. Run your finger over the fusible link and make sure it's not blown/melted.

3) Is the fuel pump priming? If so then you know the fuse pump fuse is good.

4) If everything looks good in the relay box and you're getting power to it, then follow the main wire harness. Make sure everything is plugged in tight and there are no shorts. Check your grounds. Is everything that needs grounding hooked up to the designated grounding point, either on the engine or on the chassis? Check your insulation. So on and so forth.

5) Check your ECU wiring. Are the plugs tight? Check for shorts and bad grounds. Sometimes it'll short-circuit and drain power away from the intended path.

I think that most likely you have a short in the system somewhere. It's hard to tell what the culprit is unless you go through and check every single wire.

[datboibrad]

Originally Posted by g6civcx

Okay, let's start tracing through the power flow. Can you start the engine up?

1) Is the battery hooked up correctly? Are the terminals making good contact? Is the battery sufficiently charged? Is your alternator working correctly? Is your voltage regulator in good shape? Check both high and low voltage output (sometimes people will only check the low; too much is also not good).

2) Are you getting power to the number 1 relay box? It's located between the battery and the passenger-side strut tower. It's in that area. Check every single fuse and also check out the fusible link in that box. Run your finger over the fusible link and make sure it's not blown/melted.

3) Is the fuel pump priming? If so then you know the fuse pump fuse is good.

4) If everything looks good in the relay box and you're getting power to it, then follow the main wire harness. Make sure everything is plugged in tight and there are no shorts. Check your grounds. Is everything that needs grounding hooked up to the designated grounding point, either on the engine or on the chassis? Check your insulation. So on and so forth.


I think that most likely you have a short in the system somewhere. It's hard to tell what the culprit is unless you go through and check every single wire.

ok fuel pump primes and i can start the car but i dont think its getting enough ignition power to actually start. my gauge cluster lights up just barely and the headlights turn on but wont go up or down. it seems as those the driver side relay box in the engine bay isnt getting power or isnt grounded. the ground on the frame directly behind the headlight is there and seems to be well grounded.

[g6civcx]

Originally Posted by datboibrad

ok fuel pump primes and i can start the car but i dont think its getting enough ignition power to actually start. my gauge cluster lights up just barely and the headlights turn on but wont go up or down. it seems as those the driver side relay box in the engine bay isnt getting power or isnt grounded. the ground on the frame directly behind the headlight is there and seems to be well grounded.

Is the battery good?

[datboibrad]

i charged it and it should be fine but everything seems really weak

[g6civcx]

You may have a short that is grounding out the power flow. It seems like it's draining power away from where it's supposed to go.

Sorry, wiring is really hard to diagnose. One little stray and you can spend hours looking for it. You just have to be really patient and detail-oriented. Good luck.

[datboibrad]

ok i replaced my alternator relay along with a few others and have almost perfect power but for some reason my brake lights are stuck on and it cranks but wont actually start.