I have a 87 Nissan 300 zx that every time I turn-on the key the fuse for the ecu blows. can any one help?
It could be a short in the wiring- a broken wire, or wire stripped of insulation, and touching metal somewhere. If you could look at a wiring diagram and find that circuit the fuse protects, you should be able to check the wiring without a lot of difficulty. The wire would enter the ecu on a certain pin number, and then you could check the resistance on the wire with a multimeter-with key off, and battery disconnected before unplugging the ecu. You will have to check the wiring all through the circuit, so you really do need a wiring diagram. If the wiring appears to be okay, then suspect a bad ecu. Used and reconditioned ecu's are all over e-bay. Pretty sure you could find one for your car. I just recently bought a used ecu from e-bay for my '87 Sentra, cost was $24.99, some place called auto computer wholesalers. And it works as good as a new one. Or as good as my old one, turns out that wasn't my problem, but I just kept it in the car.
Don't forget to disconnect the negative battery terminal. The ecu in those has constant power to the ecu, even with the key off. So never pull off the ecu connectors with the battery connected.
For a wiring diagram, buy a Haynes repair manual. Or register for free at autozone.com, giving make, model, year, and engine size if applicable. The repair guides do have some wiring diagrams, just not complete maybe. Or if interested, you can buy a subscription for $16.99 a month (or under $30 for a full year) from eautorepair.com. It is a DIY site by Mitchell, and with a very extensive amount of help and information. I had a one month subscription there, after getting very, very depressed with my Chilton manual. Couldn't even find a credible wiring diagram for my '87 from Chilton.
Aug 11, 2013 |
1987 Nissan 300ZX