QuestionQUESTION: hey brian whats up I have a remote start and bypass and any time I turn the power switch on for the unit my battery goes dead in a few days,i read something you wrote
(By far the best solution is to use the ground-while-running output to activate the bypass. You can try using the GWR to trigger a relay, and connect the bypass to ground through the relay; but this really shouldn't be necessary. If the GWR output can activate a relay, then it should be able to activate the bypass directly) I am wondering what type of relay to use and how to wire it I cant find any instructions on this anywhere can you help?
ANSWER: Hi Nick,
Sorry about the long delay in answering your question.
I only vaguely remember writing the answer that you quoted; as I recall, it was in reference to a remote start that wasn't working properly because the anti-theft bypass wasn't being activated. It doesn't seem like it's very relevant to your particular issue. If you can provide more details, I can see if I can help you with the problem: what models of remote start and bypass are you using, and in what year and model of vehicle? Aside from the battery draining, does the system work properly for remote start?
In most cases, a remote start system doesn't come with a true "on/off" power switch. The toggle switch that's often installed with the system is generally either a programming switch, or a "disable" switch that prevents the remote start from activating when it's turned off. It doesn't actually switch off power to the remote start unit; it just tells it to ignore the activation signal from the remote. Switching it on or off should not have any effect on the amount of power being consumed by the remote starter system. However, it's possible that you have a system that I'm not familiar with.
If you'd like to follow up with more detail, I'll see if I can give you more useful information (and with less of a delay).
Thanks
Brian
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QUESTION: its a cheap readyremote diy auto start, a gmbp bypass, the truck is a 2002 chevy silverado the unit works as it should but it runs the batt dead in a couple of days it has a on off toggle switch... I read some where on the net that the gmbp was staying grounded after the truck was off and makeing the cpu in the truck not turn off the article i read just said to use a relay to isolate the ground but i have never hooked up a relay and cant figure out which wires go where what they said was similar to what u wrote about making the gwr activate the bypass or something and .......
ANSWER: Hi Nick,
Sorry it's taking me so long to answer your questions; like most mobile electronics installers, I'm very busy this time of year. I haven't used the GMBP, so I can't really say whether it's a likely source for your problem. I did take a look at the installation manual for the GMBP. It's a 4-wire connection; there's a standard power and ground connection, a connection to the vehicle's data wire, and a "GWR" wire, that's meant to be grounded only while the remote start is running. I suppose it's possible that the GWR wire is grounded all the time, and is keeping the module active; but I'm not sure how a relay will help, because the relay would most likely need to be triggered by the same GWR wire that's presumably causing the problem in the first place. If you'd like to send a me a link to the article you read, I can look it over and see if I can make more sense of it.
You can always try unplugging the GMBP module entirely, instead of shutting off the toggle switch, to see if that affects the battery drain issue. However, you might have to reprogram it when you plug it in again.
Thanks
Brian
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QUESTION: www.xpresskits.com Q10234 - FIX: A GMBP on GM vehicles drag batteries to dead.
Last update: 12/24/2007 11:20:27 AM Article has been viewed: 1841
The batteries in these vehicles are dying because of the BCM never going to sleep (shutting down). Either the ground out when running from the remote starter system has a trickle of ground staying active or installer have connected some other circuit or relay along with the BROWN input wire for the GMBP. If the problem has to do with the output wire from the remote starter system, then add a relay to isolate the two. If installer have added a relay to power either the 2nd ignition or accessory then diode isolate this relay from the BROWN input wire for the GMBP.
AnswerHi Nick,
Thanks for the follow-up; that clears things up a bit.
The first thing to do is make sure that the brown wire from the GMBP is connected to the GWR wire from the remote start unit, and that no other wires are connected to the same output. The GWR wire is "Ground When Running"; it's a wire that's connected to ground whenever the remote start is activated, and stays grounded until the remote start is shut off again. This grounded wire is what activates the GMBP module, through the brown wire. According to the Xpresskits FAQ you saw, it's possible that the remote starter's GWR wire still has a connection to ground even when the remote start unit is not running, which means the GMBP remains activated and keeps the BCM powered.
The Xpresskit post suggests using a relay to isolate the GMBP's brown wire from the remote starter's GWR wire. Here's how you'd do this:
A typical SPDT relay, such as you'd find in any auto parts store, will have five terminals. The terminal numbers are 85, 86, 87, 87A and 30. You can connect wires to the relay using 1/4" female "quick disconnect" wiring connectors.
First, disconnect the GMBP's brown wire from the remote starter's GWR wire. Connect the brown wire to terminal 30 on the relay, and connect the GWR wire to terminal 86. Terminal 87 should be connected to a wire that runs to a chassis ground point, and terminal 85 should be connected to a constant 12v power source. 87A will not be used.
When you use a relay, you can hear and feel it "click" when it turns on and off. Once your relay is wired up, then you should hear it click on when you activate the remote starter, and click off again when the remote starter shuts off. If it's not working this way, then either you're using the wrong wire from the remote start as the GWR connection, or the GWR output is not working properly. It's important that the relay is only activated when the remote start is activated; a relay that stays on all the time will drain your vehicle battery all by itself, just from the current flowing through the relay coil.
If the GMBP really is causing the battery drain issue, due to a trickle ground on the GWR wire, then adding the relay should solve the problem--provided that the GWR wire doesn't keep the relay activated all the time as well. Hopefully, any trickle of ground in the GWR wire won't be strong enough to trigger the relay; and if the relay doesn't turn on, the GMBP won't either.
Good luck!
Brian
