97 Rodeo blowing ECM fuse!!!

[Satern]

I have a 97 Rodeo that keeps blowing the ECM fuse. It started a couple months ago, I had it checked out by an electical guy and he traced the wires and he could not find anything wrong so he said it was the ECM. I replaced it and it still does the same thing, Has anyone ever had this prolem before? Any ideas why?/ Thanks

[rur132]

Originally Posted by Satern

I have a 97 Rodeo that keeps blowing the ECM fuse. It started a couple months ago, I had it checked out by an electical guy and he traced the wires and he could not find anything wrong so he said it was the ECM. I replaced it and it still does the same thing, Has anyone ever had this prolem before? Any ideas why?/ Thanks

I'm not sure if I have a similar problem. I jump-started another vihicle with my '97 Isuzu (V6). As a result my amp meter took a dive and thought I had damaged my battery and alternator. Replacing them didn't solve the problem. I still have the "check engine" and battery light on and my amp meter is below 12V. Is this similar to your problem. I'm trying to find out if the ECM is going/gone bad. Does the ECM have a fuse? Which one is it. Any help would be greatly appreciated. Paul

[Canucklehead]

Originally Posted by rur132

I still have the "check engine" and battery light on and my amp meter is below 12V.l

I was unaware that there was an ammeter on a '97 Rodeo, let alone one that reads out in volts.

[rur132]

Originally Posted by Canucklehead

I was unaware that there was an ammeter on a '97 Rodeo, let alone one that reads out in volts.

Sound a bit unhappy son. I'd appreciate any advice, obviously, from anyone, even you. Let me know if you can help. I sure could use some electrical expertise on this one. Thanks. God Bless. Paul

[Canucklehead]

Originally Posted by rur132

Sound a bit unhappy son. I'd appreciate any advice, obviously, from anyone, even you. Let me know if you can help. I sure could use some electrical expertise on this one. Thanks. God Bless. Paul

So much for a sense of humor...

There is indeed an ECM fuse. It's fuse 12 (15A) in the engine compartment fuse/relay box... but it won't be blown if your truck runs. Could be that your new alternator is bad. It's not uncommon for remanufactured alternators to not charge as they should because of the ECM's control of the charging system. Aside from a bad replacement alternator it could be a bad ground, damaged battery cables or any other number of things.

[Davejb]

Originally Posted by rur132

Sound a bit unhappy son. I'd appreciate any advice, obviously, from anyone, even you. Let me know if you can help. I sure could use some electrical expertise on this one. Thanks. God Bless. Paul

What he was trying to say was
1. Rodeos don't have ammeteters
2. Even if they did, ammeters don't read voltage, they read amperage, so an ammeter cannot give you a reading of "below 12V" as that is a voltage reading, not amperage.

[rur132]

Originally Posted by Canucklehead

So much for a sense of humor...

There is indeed an ECM fuse. It's fuse 12 (15A) in the engine compartment fuse/relay box... but it won't be blown if your truck runs. Could be that your new alternator is bad. It's not uncommon for remanufactured alternators to not charge as they should because of the ECM's control of the charging system. Aside from a bad replacement alternator it could be a bad ground, damaged battery cables or any other number of things.

Yeah sorry about that, trouble has me bummed out. You know, I put in 2 alternators both giving me the same results. Chances of 2 (each from a different source) being bad are slim, but not impossible. They should put out about 60 amps but actually give out 20 amps. I had the 2nd tested before I installed (was good on the bench). Yes, the vehicle runs good. So, I'm stummped!! This is good info though, I'm learning about this Rodeo. Thanks for the suggestion! I'm gonna take it to someone who knows what they're doing. I'm not going to solve this is it looks like. Do appreciate your help. Blessings. Paul

[Davejb]

Make sure you take it to someone familiar with Rodeo's, this vehicle has a few quirks that can throw the uninformed for a loop. As far as the alternator, I know a guy that went through 4

[SR20Pilot]

Check the ECM relay(in the relay/fuse box on PS of engine compartment). I just completed 2 weeks of electrical gremlins and no fuel finnaly traced it back to a sticking ECM relay and the truck is running great again (just in time for a snow storm).

A bad or loose ground can also be causing your problem. I don't think a bad alternator can blow a fuse unless the diode and voltage regulator went out at the same time.

[rur132]

Originally Posted by SR20Pilot

Check the ECM relay(in the relay/fuse box on PS of engine compartment). I just completed 2 weeks of electrical gremlins and no fuel finnaly traced it back to a sticking ECM relay and the truck is running great again (just in time for a snow storm).

A bad or loose ground can also be causing your problem. I don't think a bad alternator can blow a fuse unless the diode and voltage regulator went out at the same time.

A bit of history...this all started when we jump-started another vehicle!

[Davejb]

Originally Posted by rur132

A bit of history...this all started when we jump-started another vehicle!

Which is why I refuse to jump start anyones vehicles with my own, especially with today's computers onboard, not that this helps you at all.

[rur132]

Originally Posted by Davejb

Which is why I refuse to jump start anyones vehicles with my own, especially with today's computers onboard, not that this helps you at all.

Thanks to everyone. Will take this puppy in to the shop and let you guys know how things turn out. We may all learn something here. Regards. Paul

[rodeo02]

Originally Posted by SR20Pilot

Check the ECM relay(in the relay/fuse box on PS of engine compartment)....

That's where I would start . You see more and more bad relay gremlins these days (all cars).

G/luck
Joel