5Wire door locks
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=7395
Printed Date: July 14, 2025 at 6:51 PM
Topic: 5Wire door locks
Posted By: flite_1
Subject: 5Wire door locks
Date Posted: December 30, 2002 at 5:39 PM
Hi, I have 2 relays setup according to the 5wire diagram (1990 ford taurus GL) The problem is that as soon as I reconnect the neg. battery cable to power up the car, the fuse blows out rather instantly. The fuse I'm referring to is on a 12ga wire coming from the battery and powering the 2 relays as described in the diagram. It's been blowing 15-30a fuses. I've checked and rechecked the wiring in case I might've incorrectly connected something. And it doesn't look like it's shorting out to ground anywhere. Mind you all the points on the 2 relays that req. +12v are all routed to a single wire that houses the inline fuse. Should that concern me? I've seen similar diagrams that show each of the +12v legs in the relays connected to it's own (usually 10a) fuse. Would that help? Does anyone have an idea what might be blowing my fuses? Thanks
Replies:
Posted By: flite_1
Date Posted: December 30, 2002 at 5:45 PM
...and another thing; in case it might be the relay itself. How can I test the relays with a DMM? By that I mean which points do I contact. Should I try a continuity test? etc.. you get the idea... thanks again
Posted By: brianh
Date Posted: December 30, 2002 at 8:57 PM
Pins 87a and 30 should always have continuity when the relay is not energized. Pins 87 and 30 should not have continuity until the relay is energized. Also make sure that there is no wires touching each other on the relays themselves. (all it takes is one strand to short out) Whatever it is sounds like you have a dead short to ground some where in the cicuit. Check the entire length of the 12 volt wire to make sure there is no naked spots. Let us know what you find. Brian
Posted By: flite_1
Date Posted: December 31, 2002 at 3:35 AM
Thanks Brian for the helpful info...I'm fairly sure there's isn't anything shorting out to ground, but as you said- there may be some naked spots on the wire. And perhaps if there are any it might be in the engine compartment where It's connected directly to the batt. Another question, seeing as having all the +12v legs on the relay connected to a single fused wire isn't a problem, what amperage should I use for the fuse? Should I keep that setup or abandon it for individual fuses per leg (and at what amperage?) thanks!
Posted By: cpgoose
Date Posted: December 31, 2002 at 6:41 AM
hey flite_1, I sort of did the same thing that you did, only I didn't have a fuse connected. I reconnected my negative cable, and blew out 2 actuators! Then I replaced the actuators, connected all 4 power wires to the same 12volt wire, and then fused it with a small fuse (like 5 amps I think). Anywho, I was afraid of blowing something again, so I didn't disconnect the negative cable the second time, I just installed the power wires for the relays under the dash (and crossed my fingers), and everything was fine. (Still is, too, after about 3 months).
Posted By: brianh
Date Posted: December 31, 2002 at 7:03 AM
you might want to try hooking your 12 volt fused wire to the 12 volt constanr wire under the dash. Tell me what type car you have and I will tell you the wire color. Brian
Posted By: flite_1
Date Posted: December 31, 2002 at 2:16 PM
cpgoose: just wondering where your 12v wire was connected to, as mine is connected straight to the batt. or did you attach it to a constant 12v wire in the ignition harness? Also what's your make and model? And one last thing, how did you cut the lock & unlock wires? Was it at the driver's or passengers kick panel? Did you have to locate other wires besides those two and how did you know which end was to the motor and which was to the switch? I'm a little bewildered at all this. Thanks Brianh: It's a '90 Ford Taurus....I'll try hooking it up under the dash (10g yellow if I recall) and see what happens...
Posted By: cpgoose
Date Posted: January 06, 2003 at 6:54 AM
hey flite_1....I used the 12v constant wire under the dash (from the ignition harness). I didn't have to cut any lock unlock wires because I installed acuators....in other words, I didn't have power door locks to begin with  But, I think you can find the lock/unlock wires in the driver's kick panel for the driver's and passenger's door. Why do you have to know which end is the motor and which end is the switch......can't you just "piggyback" the wire when you find it? Hope this helped.
Posted By: mobiletoys2002
Date Posted: January 06, 2003 at 7:23 AM
you need to determine the switch side becaus eyour wires will rest at ground and pulse positive on lock unlock (reversed polarity) when you find the suspect wires cut one of them and check door lock operation if all switches stop operating you have one of the correct wires reconect that wire and cut the other wire if the doors stop working at the switches you have found thew correct wires for a 5 wire sytem. Use a meter and take the red lead and probe one side of the cut wire check for voltage on lock or unlock the side that shows voltage is the switch side.on lock
Posted By: cpgoose
Date Posted: January 06, 2003 at 7:27 AM
hey mobiletoys, did you ever get my email? I emailed you about 2 weeks ago or so.
Posted By: mobiletoys2002
Date Posted: January 06, 2003 at 6:20 PM
i have not gotten it which mail di dyou send it too??????anyways send it again to mobiletoys2003@aol.com see ya .
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