What could have been damaged in reverse polarity?

[StrayInArizona]

Hello, I'm Ryan. 25 and I'm pretty much self taught and advise given mechanically inclined. I'm very hands on. But in all reality I don't have enough experience.

I have a 1998 Ford Explorer Efi 4.0 2Door Sport. Vin X, 4x4.

I needed to borrow the battery out of my buddy's car so I could move my Explorer right up the road so that I could work on it when the new engine comes. I am doing an engine swap.(Definitely could use a link on swaps. Same engine.) I didn't realize when hooking the battery up but his battery was reversed. I hooked it up and for one second I realized it was wrong. And I disconnected it immediately. The engine has a knock but has always started up. Once I hooked it up correctly and I went to try to start it up again it would not. It still turns over. Would this have to do with the alternator? I have seen threads about the alternator being damaged due to this. I have a suspicion that it is the fuel pump because it turns over. When spraying carburetor cleaner in there it tries to start. Honestly my question is what all could be damaged when doing this? Like I said I'm putting a new engine in it. I need to know what diagnostic to run when the time comes. Please let me know any possible components that have could have been damaged. I checked the fuses and didn't seem any were damaged other than number 30 which is for the lights.

 

[peterk9]

It may help to state which model, year and trim you have.

Peter

 

[Turdle]

Moved to 2995-2001 sub forum. Per profile

Check the power diode in power distribution box. Check all fuses, including main fuse powering the power distribution box. PDB does house an alternator fuse.

Also check interior fuses.

Check fuel pump inertia switch.

 

[StrayInArizona]

Which one is the power diode and which one is the main fuse? Sorry.

 

[Turdle]

Main fuse is bolted to side of PDB. Power diode looks like a black fuse with a sideways prong so it cannot be inserted reversed polarity. Should have an arrow, or, diode symbol on it.

 

[Josh P]

Which one is the power diode and which one is the main fuse? Sorry.

Most like is the power diode, that is it's purpose, to protect the electrical system from reverse polarity. Google has images of the diode, and fuse panel.

 

[hjc4604]

Hello, I'm Ryan. 25 and I'm pretty much self taught and advise given mechanically inclined. I'm very hands on. But in all reality I don't have enough experience.

I have a 1998 Ford Explorer Efi 4.0 2Door Sport. Vin X, 4x4.

I needed to borrow the battery out of my buddy's car so I could move my Explorer right up the road so that I could work on it when the new engine comes. I am doing an engine swap.(Definitely could use a link on swaps. Same engine.) I didn't realize when hooking the battery up but his battery was reversed. I hooked it up and for one second I realized it was wrong. And I disconnected it immediately. The engine has a knock but has always started up. Once I hooked it up correctly and I went to try to start it up again it would not. It still turns over. Would this have to do with the alternator? I have seen threads about the alternator being damaged due to this. I have a suspicion that it is the fuel pump because it turns over. When spraying carburetor cleaner in there it tries to start. Honestly my question is what all could be damaged when doing this? Like I said I'm putting a new engine in it. I need to know what diagnostic to run when the time comes. Please let me know any possible components that have could have been damaged. I checked the fuses and didn't seem any were damaged other than number 30 which is for the lights.

It seems unlikely that the alternator would be affected, however virtually any other electronic components would be at risk, like the ECU. That, of course, would depend on whether or not Ford chose to equip the components with reverse polarity protection circuitry.Electro-mechanical devices like the fuel pump and starter would probably run in reverse. Not sure what potential damage that might cause. Good luck

 

[StrayInArizona]

Currently checking the main fuse. I will come back after checking a few things. Update soon.

 

[sehaare]

Hang in there, while we don't like to admit it, as some point most of us have probably done dumber **** when starting out.

 

[StrayInArizona]

I put in a new main fuse and it still does the same thing. Crank, no start. I took a look at the power diode. I'm not sure if O'Reilly's has one. I might have to order it offline. After reading about it it definitely sounds like this could be the problem. But with my luck I'm pretty sure it's not going to be. Haha. How would I double check to make sure it's getting gas? I feel like if it's not electrical related it has to be fuel related. If I didn't know any better I would guess it wasn't getting gas. But in this case I hooked the battery up wrong so..

 

[Turdle]

How to: - Ford Explorer Engine No Start Procedure

This procedure diagnoses a No Start engine problem. The procedure is based on information from the Ford Service Manual and my personal experience. The numbered steps should be performed in the order listed. 1. Does "THEFT" blink rapidly with ignition key in Off, On or Start? Yes: Verify key...

www.explorerforum.com

Instead of us asking a bunch of questions, the above procedure might help narrow it down.

A cheap dial type air pressure gauge can be used on the shrader valve on fuel rail to check pressure.

Let us know what you find.

 

[StrayInArizona]

I'm trying really hard to understand these threads but I'm at a loss. I got stuck at PCM power procedure. A lot of it doesn't make sense and a lot of it doesn't apply. There is only 2 years posted and neither one of the fuses really lined up with my fuses. All different amps. I've been at it this whole time. I've looked through all of the forums sent and I've tried a few different parts of each one. I tried going in order and it doesn't really work to my advantage. I feel like I'm gonna blow my starter. I disconnected the fuel line at engine, no gas came out even when turned over.

 

[Turdle]

Does the check engine light illuminate with key turned to on?

 

[StrayInArizona]

I don't know if this information helps but the electrical on the inside still works. AC still blows radio still works horn still works. Lights come on.

 

[StrayInArizona]

Does the check engine light illuminate with key turned to on?

I don't see a light that says check engine light. There is a light that says check gauges. I do believe it had a check engine light at one time. But I couldn't remember when I started doing this test. It doesn't show when turning the key to on.

 

[Turdle]

Ok, this means the pcm is not getting power. Good clue. Need to check pcm power relay and fuse.

 

[Turdle]

Solved - Fuse and relay locations--2nd generation power distribution box Layout-

I think this is a good sticky candidate-- Fuses are listed here * = maxi fuse 1*=50A I/P fuse panel 2*=40A blower motor relay 3*= 50A 4 wheel ABS module 4*=20a Main light switch-Instrument cluster 5*=50A Ignition switch, starter relay 6*=20A Transfer case relay 7*= NOT USED 8*=20A Auto Ride...

www.explorerforum.com

First post is for 98 model year

 

[StrayInArizona]

Seems to be good. No issues with the fuses.

 

[Josh P]

I'm also in Phoenix, if you would like assistance, let me know.

 

[StrayInArizona]

I'm also in Phoenix, if you would like assistance, let me know.

Yeah, that would be great. I'm located right around the corner from the Phoenix Children's Hospital. I also just recently purchased a crate engine and I'm waiting for that to be delivered. I need to get this to be able to start so I can slap the engine in. I have very little experience in engine swaps and I definitely would be willing to pay for assistance. I have a few friends who can help out