My car keeps blowing fuses #8 and #9. I've spent a fair amount of time searching this forum about what to do about it, and I've gathered a lot of what I've found together into a "electrical maintenance" list that I'm going to go through over the next couple of weeks to try to fix my problem. Thought I'd share it here so folks can give feedback.

Cleaning grounds

1. Clean the transmission ground (under the car, above the transmission)
2. Negative battery ground (in the engine compartment above the battery, passenger side)
3. Clean the ground to the fuse panel (behind the fuse panel above driver's footwell). There is also a POS terminal lug behind the fuse panel. This POS distribution lug should be tightened. (DISCONNECT battery NEG terminal FIRST before dropping fuse panel and tightening POS terminal lug.)
4. Check and clean fuses and fuse panel "fingers" that hold the fuses (on the front side of the fuse panel)
5. Clean all spade connections to the fuse panel (on the back side of the fuse panel).
6. Clean all connections on the relay board (in the engine compartment, driver's side)
7. Check and clean the two fuses and fuse panel "fingers" on the relay board (in the engine compartment, driver's side)
8. Clean the ground to the relay board (in the engine compartment, below the relay board, driver's side)
9. Clean the ground connections for the headlights (in the front trunk, behind each headlight)
10. Clean the three spade connections to the fresh air control (behind the dash)

With a voltmeter:

1. Measure battery POS voltage on terminal and terminal clamp to chassis ground (not to negative terminal) (checks POS battery connection: both should read >12.6V during lights on/engine running)
2. Measure battery NEG voltage on terminal and terminal clamp to chassis ground (checks neg battery connection: both should be 0 V)
3. Measure engine Coil POS terminal to chassis ground. (Should read >12.6V)
4. Measure engine block to chassis ground (Checking engine grounding; should be 0 V)
5. Measure voltage at proper turn signal and headlight fuses to chassis ground. (Should be >12.6V)
6. Pull the fuse that keeps blowing. One side of the fuse is connected to the voltage source, the other to the load. Measure the resistance between the load side to ground. More than likely, it'll be low enough so that when 12V is applied, the current will exceed the fuse rating (e.g. you measure 1 ohm, the fuse is rated at 8 A, I = V/R = 12/1 = 12A, too much current, fuse would blow)
7. Use your wiring diagram and go back through the circuit, systematically disconnecting components. When you hit the location of the shunt, the load resistance you're measuring will jump up. You've just found your problem.

Fuses (left to right)

1. Left high beam
2. Right high beam
3. Left low beam
4. Right low beam
5. Left parking/running lights
6. Right parking/running lights
7. License plate lights
8. Brake lights, horn, wipers, lighter, fan
9. Gauges, “G” light, turn signals (and reverse lights?)
10. Fog lights (if fitted)
11. Hazard lights, interior light
12. Headlight motors

Common electrical issues

Car won't start

• Clean both battery terminals. Make sure that the negative ground to the battery is clean and tight.
• In later cars, the seatbelt relay can cause problems. Bypass the seatbelt relay below the passenger seat by connecting the Yellow and Yellow/Red wires directly to each other with a jumper.

No power to gauge lights, turn signals, wipers, horn, tachometer, voltmeter, fuel gauge, etc. Alternator (“G”) light is on.

• Check for blown fuse #8 or #9

Fuse #9 keeps blowing

• Check instrument bulb connections behind the dash and center console gauges, they can come loose and ground out on the dash
• Check transmission ground
• Check wiring to the backup light switch on the transmission
• Check the double spade connector on the back of the fuse panel, these can short if they touch the fuse panel housing.
• Check for shorts in the wiring to the rear lights and license plate lights

How often do the fuses blow? as soon as you put them in? If so try pulling the wires off the fuse panel till you find the one that blows the fuse. Trace that wire to find the problem area. Seeing as you have two that blow together, maybe a screw went through the harness somewhere? If the fuse doesn't blow till your driving, try and keep track of what you did, used turn signals, turned on lights, etc. To avoid burning through a ton of fuses, you could wire up a two prong turn signal flasher relay and hook it across the fuse terminals. the relay will open when the current gets too high and allow you a little more dianostic time with out popping fuses one after another.

BTW, I think the 74+ 914s do not have the power distribution block up above/behind the fuse panel.

--DD

I had #8 blowing randomly. I finally tracked it down to the gas pedal linkage catching on the brake light switch behind the pedals.