jdmgsr420

Just purchased my first v it's a 1998. Having electrical issues.
First tried to start it and nothing. Replaced battery and rewired all
Main power and ground cables under the hood. I then checked and replaced
All the blown fuses.

#1
The radio/backup fuse pops instantly upon insertion.
What could cause this? I completly unplugged the head unit and
It still arcs and blows as soon as I put a new fuse in regardless of ignition position

#2
Ecu/Fi fuse pops as soon as I turn the key. The check engine light blips the same time the fuse blows and then no cel.
I am thinking main relay so I pulled it out and it looks kinda overheated and smells kinda bunrt. The fuse does not blow with the relay disconnected.
The fuel pump won't prime because of the ecu and it has no spark, camshafts moving fine. All the wiring under the hood looks ok nothing obvious.
Does this sound like a main relay problem? I have one on order.

I've owned a 1998 Integra with a JDM B18C Swap for the last five years so I'm not a complete noob, looking for any advice you can give. Thanks in advance.

el crapitan

with the main relay disconnected, does the radio fuse still blow?
and you're talking about radio fuse 47 under hood, correct?

jdmgsr420

Yes the radio/backup fuse under the hood. It blows no matter what.
With the MR disconnected it still pops with the ignition on or off.

The ecu fuse does not blow with the MR Discontected.

el crapitan

aftermarket stereo in there?

el crapitan

hmmm. these circuits share power at the under hood fuse panel. they're also both hot at all times there. these problems are connected. the radio circuit is closed at all times. the white/ blue tracer wire must be radio memory. that circuit also supplies back up power for the ecu and data link connector. those circuits must be closed at all times as well.
the fi circuit is closed with key on. it supplies power, ultimately, to the injectors and energizes the coil to close the fuel pump circuit.
there must be a short between the battery and the under hood fuse panel where those two circuits are shared. i would unbolt the under hood fuse panel and have a look underneath. look for chafing/burnt wires. it's shorting somewhere there. makes sense now. that's why when you unplugged the radio, the fuse still blew. because that circuit also supplies power to the ecu and data link connector. then, with the key on, the fi circuit closes, so now that circuit has a path to ground. but the short to ground before the fuse panel draws the excess current to blow the fi fuse. and with radio fuse blown, you won't get spark, since it supplies power to ecu.
that's also why your battery was dead. the short to ground directly off the battery.
that's gotta be it

jdmgsr420

There is an aftermarket deck in it however looks like it was professionally
installed the wires are soldered and shrink wrapped. I will pull that fuse panel and have a
Look.
What do you think about the main relay?
A lot of people have said they have had to replace the MR
in there Honda, would the MR Cause these problems?

jdmgsr420

Thanks for your advice, much appreciated.

el crapitan

no no. it's not the relay. or the deck. only reason unplugging the relay allows the fuse not to blow is because the fi circuit remains open with key on. it's a short between the battery and the under hood fuse panel where the 2 circuits share power. i guarantee it.


to find the short, you'll have to just hunt for it. normally i would suggest connecting a test light in line of the radio fuse, and wiggling the harness until the light goes out, but i'm afraid it will just blow the test light right away, since it's hot at all times and the draw is higher than 15amps since it also blows the fi fuse.
there is only one safe way to find it besides physically eyeballing the harness. you'll need to use a multimeter and perform voltage drop testing between the fi fuse and the battery. because the power source for these 2 circuits has shorted to ground, this creates a load on that circuit and that allows us to perform a voltage drop test. i'll walk you through this if you have a multimeter

el crapitan

actually, i thought of an easier way of finding that short if you don't have a multimeter, but you'll need a test light.
disconnect the positive battery cable and install the test light between the positive cable terminal and the positive battery post. since you have a short to ground, the light should illuminate. even if it lights very dim, you should get something there
now, start wiggling the under hood harness between the fuse panel and the battery. as i said before, the short may be underneath the fuse panel though, so you may need to unbolt it to gain access. do this until that light goes out. when you've found the spot that causes the light to go out, you've found where the short is located

but first, we have to be sure the battery has enough charge to power the test light. the short may have drained it already.
to do this, hook the test light up between the negative and positive battery terminals. see if it lights it.

jdmgsr420

Pulled the under hood fuse box opened the bottom plate and everything
looks factory, no burnt wires. Followed the wire harness under the battery tray and it looks fine no bare or melted wires. Im absolutely stumped here.
I don't have a multi meter or test light, guess I should invest in them.
All visible wiring looks ok.
What else would cause these blown fuses?
A blown ecu maybe?
Would a fried coil cause theses fuses to pop?

jdmgsr420

Anybody had this problem before?

All advice is welcome and appreciated.

el crapitan

trust me, bud. it's difficult to explain without you seeing the wiring diagram. but i gazed at my practically useless haynes wiring diagrams for a fair bit of time to figure it out. tried finding all different scenarios, and the only way that these 2 fuses could blow in this order is a short to ground between them and the battery. there is no way that it can be the relay, ecu, coil, etc.. trust me on this.
you need to get a test light. you can even rig one up with a marker light bulb and a couple sections of wire
or you can buy one for under 5$. best investment you can make, for future use as well

oh and btw, it's the fi/em fuse. not ecu lol. that actually threw me for a loop for a few minutes

jdmgsr420

I will pickup a test light and try to find a short.
Could the whole fuse panel be the culprit, as I said no wires
look burned. What a headache tho, been at this for a week now.
Really appreciate the help.

el crapitan

it is possible, yes.
although the wire(s) you're looking at may not actually be burnt. could just have a very minor chafing. the test light will tell us immediately if there is, in fact, a short. which i'm certain there is. from there, it's just a matter of finding it and making that light go out

el crapitan

any updates?

jdmgsr420

There are multiple shorts, have yet to find them all.
Two under the dash, the wiring in the taillights was hacked into
for trailer lighting which were grounding out on the frame.
The Main Relay is also fried beyond recognition. The wires going to the
horn were grounding out.
The MR I ordered should be in next week, I hope that will take care of
blowing the EM/FI Fuse, and I'm just wrapping up the wiring that I had to rip out.
Why people do such HACK jobs when it takes no more time at all to do a pimp
job that will last for years is beyond me.
I have also noticed that there was some left overs from an Alarm/CarStarter, how can
I make sure that it is fully disabled? Where online can I find a wiring diagram for my
1998 CRV.

el crapitan

hmmm. so multiple shorts eh? yea that was the only other possibility. guess it was just a coincidence that the 2 circuits were connected at the fuse panel.
for the diagrams, i'm not sure. i use alldata at work, and have a shitty haynes manual at home

did you pick up a test light though?

jdmgsr420

So I'm still stuck, wanting to drive this truck so bad.
After re-wiring the circuits I have found with shorts still blowing the same
Fuse Radio/Backup. ECM,Colck,Radio unplugged and it still blows as soon as
the fuse is inserted.
I have a test light and from the positive battery terminal to the under hood fuse panel
it lights up, thus telling us there is still a short.
How do I go about finding which exact wire is grounding out and then what? Rewire that
circuit, how do you know exactly what components are drawing current from that fuse?

Again any help would be greatly appreciated, trying to get this truck on the road with a budget of not much more than $0.00.

I'm thinking I might need some paid professional assistance with this one.
I thought it would be an easy fix.

el crapitan

so does the fi fuse still blow with key on? it should, because it receives power from the radio circuit before the fuse.

you are correct. test light is lit between radio fuse and B+ indicates a short to ground between them.
you don't need to know what's all involved in the entire circuit, just between the fuse and the B+, since electricity can't move past the blown fuse, so the short can not be beyond it. that is, as long as you're probing the power side of the fuse. you are, right?

basically, it's just a matter of making the light go out now. unbolt the fuse panel. with your test light still connected, jostle the harness until the light goes out, then zero in on the spot that made it go out

jdmgsr420

Just to update
Still have yet to start my CRV.
I could not find a short under the hood with the test light.
So I started searching under the dash. Im very upset and frustrated by what I've found. There was an aftermarket alarm/remote starter installed.
I know the problem has to be some where in this mess of wires
I'm trying to upload pics now.

jdmgsr420

I have installed a new main relay,plugs/wires,cap/rotor and a new
Ignition coil. These made no difference.
Can anyone give me advise on how to remove remote starter/alarm and rewire it back to
stock? Not to much detailed info from google.

el crapitan

okay. let's start fresh here.
with the test light between the pos battery terminal and the radio fuse under hood, light illuminates?
and with the test light between pos battery terminal and fi fuse (fuse removed), light illuminates?
is this correct?

jdmgsr420

With the key off:
The BACK UP.(RADIO) Terminal illuminates the testlight only on the passenger side of the terminal.
The FI/EM Terminal does not illuminate the testlight at all.

With the key in the on position:
The BACK UP.(RADIO) Terminal Iluminates the testlight on both sides of the terminal.
The FI/EM Terminal now iluminates the test light on the passenger side of the terminal.

jdmgsr420

Some info.
Replaced: Main Relay,Coil,Cap&Rotor,Plugs&wires.
New Fuel Filter,Air Filter.
I installed a Brand New Drivers side power window motor and regulator.
Replaced every light bulb.

All regular maintenance stuff but can now rule all of them out as a cause to this problem.

el crapitan

and when you're probing, you have 1 of the test light leads hooked up to the pos battery terminal, and the other end probing the fuse terminals at the fuse panel? both fuses removed

if not, please explain how you're probing