Four 20A under hood fuses always fail to light the test light

MAILMD32217

MEMBER
1998 ACURA CL
3.0L
V6
2WD
AUTOMATIC
153,000 MILES

There appears to be an electrical problem with my fuses. Four 20A under hood fuses always fail to light the test light while the rest of the under hood fuses light the positive red light. I pulled and inspected the 4 fuses and did not see any reason why they would not work. Then, replaced all 4 fuses with new 20A fuses, they all 4 do the same thing, don't light up the test light. When I tested the interior fuses, none of them light up, including the 7.5A start signal fuse. I have been trying to diagnose a no crank start failure, including the fuses. When I test the positive starter solenoid post, it lights up the positive test light, indicating that the positive circuit from the battery to the starter solenoid is receiving current and the starter motor may be failing to receive current or the motor has failed. I will do more tests with the starter, but why do the all the interior fuses, especially the starter signal fuse and the 4 new fuses fail the light test?

3 Replies

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello again,

Okay, so everything that we need to diagnose the problem is going to be in the wiring diagram of your vehicle's starting circuit that I have included in the diagrams down below. The reason that you are getting battery voltage at the positive solenoid post is because the wire going to it is coming straight from the battery. Follow the wire from it and you can see it is coming straight from the battery. The reason the electricity is not going any further is the starter solenoid is set up just like a relay. The coil on the other side of the solenoid needs to have electricity going to it so the switch can be pulled shut by the electromagnetic coil for the electricity to make it from the positive solenoid post to the starter. The part of the circuit that feeds the electricity to the coil is the where the fuses are inline. Follow the electricity's path from the coil on the starter solenoid. It's the black/white wire. It goes to pin #3 on the starter cut relay. This is the switch or "power" side of the relay with a switch that must be closed for the electricity to make it here. How does the switch get closed. When the other side of the relay gets electricity to it. The other side is the coil or "control" side of the relay. It gets electricity from the neutral safety switch and the ground is provided by the starter cut relay control. The neutral safety switch will let electricity flow only when the gear selector is in neutral or park. Following the electricity's path from the neutral safety switch it goes back to the under dash Fuse Relay Box where Fuse 9(7.5A) the starter signal fuse protects this part of the circuit. The two separate circuit paths come back together here via a splice and the path heads back to the ignition switch where the electricity is only allowed through the ignition switch in either "RUN" or "START". From the ignition switch it runs to pin #3 of connector 906, through the Under dash Fuse Relay Box and out pin 1 of connector 404 to the Under hood Fuse Relay Box and through fuse 18(50A) IGN SW and fuse 15(100A) Battery fuse and then from there to the positive battery terminal. If you have replaced the fuses that protect this circuit and they are blown that means that you have a short to ground somewhere in the circuit. Please use this wiring diagram to track down the short to ground and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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Saturday, July 20th, 2019 AT 3:13 PM

MAILMD32217

MEMBER
23 POSTS

Hey,

There are no diagrams attached as indicated in your message.

Can you check what is missing and add them your reply?

In the meantime, I performed a few more tests on the starter. The solenoid starter switch and the starter post both failed the light test. The solenoid and the starter do not appear to be able to receive current to activate the solenoid nor the starter. I performed a different separate test of the starter. I disconnected all three posts to the solenoid and tried to jump start all three solenoid posts, but got nothing but a few sparks from the starter post. No click, no noise, no movement from the starter nor solenoid. I used alligator jumper cables and battery jumper cables to set up the connection between the battery and solenoid posts. I was expecting the starter motor to at least turn over to indicate possibly a failed solenoid or starter, but both appear to not receive any or enough current to activate. I'm not sure if it is electrical or the starter/solenoid or all of them. What do believe?

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Saturday, July 20th, 2019 AT 6:54 PM

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello again,

Okay, sorry about not sending the wiring diagram of your vehicle's starting circuit. I have included it in the diagrams down below. Look at the wiring diagram and read my description of what is going on. In my description we will be working backwards from the starter solenoid back to the battery. At the end, you should completely understand what is going on with the starting circuit. When tracking down a short to ground, what you are looking for is a bare wire with no insulation that is shorting to the frame(ground) or something else that has a ground path back the negative battery terminal. Please go through the guides provided, and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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