RTH: Pulled factory alarm, now truck won't fire

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

T

trk204

10 Year 15 Year
Joined
Nov 27, 2008
Threads
57
Messages
160
Location
Somewhere, Out There
RTH: Pulled factory alarm, now no CEL light

I just got finished pulling the factory RS3200 alarm system from my 97 fzj. Removal seemed pretty straight forward, no wires were cut, a couple of splices removed. The battery was disconnected during removal. Once I mated all the connections up, the truck will turn over no problem but won't fire.

I also noticed the check engine light does not come on when I insert the key and turn it to acc before starting, which I'm pretty sure it did and I'm pretty sure I read somewhere that if it doesn't come on you have an ECU issue.

I've tried re-mating all the connections that I was into and still no CEL comes up.

I also installed a CDL switch at the same time, but thats so mundane I don't see how it would have effected this.

The only issue I could think of was maybe the wire splices broke a wire when getting removed?

Anyone have any ideas?

Ryan
 
Last edited:
I would look for something that was cut (there should be at least one the rest will been just tapped ) on the ign. circuit when the alarm was installed (port install so its crappy at best ). The way the alrarm works is it disables the power to the coil so you need to run that wire through the alram "brain"
 
Are these alarm systems equipped with a feature that requires you to lock the driver-side door, then unlock it --using the key-- and only then will it start? My Grand Cherokee requires this if you disconnect the battery.
 
You describe the ignition lead being cut.
Do you have any pics of the alarm you pulled out?
If the wiring was spliced into the heavy gauge wires that came out of the key, that is probably where your problem is. Also, allot of people accidentally pull the ignition plug out half way when pulling on the wires.
 
No experience here since I dont have a factory alarm.... but why would there be slices on factory installed alarm?
 
You're right, there was a "jumper" cable that was soldered into the 7.5a IGN fuse wire. I snipped the alarm wire at the base of the original black/red wire.

I was just outside with my voltmeter, and I connected up to the exposed part of the black/red wire with a known good ground (which you can see in the pic), cranked the motor and didn't get any volts coming through the wire. The 7.5a fuse is good. The other pic is the before shot of the wire that got snipped.

Ryan
ignwire.webp
ignwire-harness.webp
 
retro, I think there was 3 splices into the factory harness and the one soldered wire as per above.

I was trying to reverse the install as per the 3200 manual pdf floating around. I'm going to head out, and peel back the insulation on the ign wire and see if I can get some volts from a good piece of wire rather the solder blob.

Ryan
 
Here is a pic of a portion of the alarm harness that attaches to the ignition switch. Note the big black wire soldered in there.

I don't see anything in the installation manual calling for this jumper wire tho...
harness.webp
 
I tested black/red wire's continuity from the female fuse socket to the male end of the ignition switch and it came back ok. I Also noticed the cdl switch I installed isn't working, but I would think that's a symptom of the ecu not playing nice.

I am curious as to why I'm not getting any volts down that wire when cranking/key in on position.
 
with the key in the on position I can see 12v at each fuse socket including ecu-ig, ecu-b except for ign. Something must be interrupting the power to that circuit. I'm not sure which fusable link it's on, but everything else is working so i can't see it being a link.
 
I would have to guess when you removed this plug and plugged the factory plugs back together, the ignition "or other terminal" became dislodged from the plug.

Just to test it, plug that plug back in line with the ignition plug and try to start it, verifying all the terminals are firmly in the molex connector.


trk204 said:
Here is a pic of a portion of the alarm harness that attaches to the ignition switch. Note the big black wire soldered in there.

I don't see anything in the installation manual calling for this jumper wire tho...
Click to expand...
 
The alarms interrupt the starter circuit, not the ignition circuit.

The problem is 100% something you cut or did when removing the alarm, just re-trace all your places that you worked on / pulled something out and you will find it.

I really think the molex plugs have a wire slightly dislodged from it "probably the ignition.
Check it at both sides of the plug for power when using the key
 
Yeah I'm going to get back at er in the morning. Way too many bugs out with the flood light going. I did manage to test the ignition switch as per the fsm continuity tests and all came back good.

I'm in the middle of grabbing the EWD, so I should have a little more info going into the battle tomorrow.

I have a sinking feeling one of those splices broke a wire on removal.... The EWD should help with figuring that out.

Thanks guys.

Ryan
 
Ok well I think I'm on the right track. I went and connected up the ignition switch connectors from alarm harness back into the truck (ONLY the ignition switch connections). Still no CEL. Was sitting there drinking beer and thinking about it, tried connecting up the jumper back to the 7.5a IGN fuse (the crappy picture from post #6), and then all of a sudden I get a CEL light when turning the key to the ON position. Only the motor won't crank as the harness is wired for the starter cut relay.

So now my question is, did they cut the IGN circuit somewhere upstream then jury-rig this jumper to get +12 to the ign circuit? Looking in the rs3200 install manual (thx slee for that), I can't see anywhere in the step when they are installing the alarm section into the ignition switch.

With this turn of events, I'm fairly confident I didn't break anything :)

Ryan
 
Probably not intentionally.
I owned a car audio store for 20 years, and there is no end to mess installers created putting in alarm systems.
Pull the harness plug back out, see if it starts.
Most likely they put a fuse adapter in the fuse box that spread out the fuse holder where it wont make contact again and had to bypass it, or messed something up when installing the wiring and had to rig/repair it.
 
Just got back in from hearing her fire up again! After I jumpered the socket where the starter relay plugs in essentially eliminating it, and re-connecting the jumper wire from the alarm iginition switch to the IGN wire it will fire up.

So it's enough where I can at least drive it to go watch the UFC tonight :)

But there is def something fishy with that jumper wire they spliced in there. More to come tomorrow.
 
I've had starting problems from the alarm system when i have had the battery cable disconnected. I would re-connect the cables and get nothing when turning the keys. I figured maybe the door lock position might have something to do, so when i would hit unlock the locks would move back to the locked position. After scratching my head for a minute, i turned the key to the first detent, powered the radio on and changed stations and at the same time unlocked the doors and presto.... She started right up! I think the alarm is tied in with the radio. This could be the reason you don't get any ignition. Hope this helps!
 
From the looks of the harness, and what Jolly says above, I think the only interruption intended was for the starter cut relay, not the ign circuit. So I'm not sure why they have that jumper powering the ign circuit.

Tomorrow, I'm going to figure out which pin on the ignition switch connector is getting jumpered and then I guess trace that back to the batt to see why it needs to get jumped. I just wish I could read the EWD a little better :)
 
Just following up on my issue. It was indeed a blown fusable link at the battery. AM2 I believe which only supplies power to the ignition circuit.

I replaced the fusable link, and pulled out the part of the harness I needed to get it to run, and sure enough, now I get power to the ECU.

Not sure why/how the previous shop would go to all the work of figuring out which wire to jumper under the dash rather then replacing the fusable links..... But hey, at least it's working :)

Thanks for the help guys.

Ryan
 
You must log in or register to reply here.

Share this page

Back
Top Bottom