Viper 5305V Trunk Release Negative Output Problem, 1990 Ford Mustang

If you find that the miniature relay works ok electrically and are looking for a way of mounting it, I have a suggestion. You can epoxy the top side of the relay to your Viper case - that has worked well for me when it is just 1 or 2 outboard relays.

If you want to go the transistor route, you need a PNP with a gain (hFE) of 20 or more. It only needs to be rated for 200 mA of current or so since it's just triggering a relay. Connect your 1000 ohm resistor from the Viper's output to the base. Connect fused constant power to the emitter. Connect one of the relay's coil terminals (85 or 86) to the collector and ground the remaining coil terminal. Connect terminals 87 and 30 to the opposite sides of the trunk release switch.My ex once told me I have a perfect face for radio.

https://www.the12volt.com/installbay/forum_posts.asp?tid=114792&KW=2n6491#556471 Very old post. Radio Shack is no longer an option for the transistor but I am sure you can locate one.

Well not the update I would have wanted to post but I recieved the mini 10a relay that I ordered and before attempting anything I made sure it worked and it does. Moving on to wire it accordingly to get the trunk to pop it did the same thing as all the other relays I’ve tried, nothing. I don’t get it, I tried wiring it all sorts of ways and I even tried to tie in the previous installed grounds from the viper alarm to other strong grounds on the car and it didn’t make any difference. The negative 200ma output is just too weak. No matter what I tried I couldn’t get the relay to click using my alarms negative output. I’m gonna attempt to buy a transistor and wire it up but honestly it’s just looking like my trunk pop will never work right with my current alarm.

Out of curiosity, what is the coil resistance of your mini relay? There are different types available. Do you have a link? It will work with a transistor- even if you have to use a Darlington.My ex once told me I have a perfect face for radio.

If it is lighting an led, the diagram I posted will definitely work. All the transistor needs is the sight of ground to work.

So I just measured the coil resistance and it’s showing 125 ohm. The link to the relay: https://www.amazon.com/HELLA-965453041-Micro-SPDT-Relay/dp/B000VU9A28 As for the transistor I am currently trying to find the correct one for this application and will be trying to wire it as suggested. With just the output and the resistor, and 12v constant power It does light up the led but very very dim. Hopefully the transistor can solve my problem.

redfox90 wrote: So I just measured the coil resistance and it’s showing 125 ohm. The link to the relay: https://www.amazon.com/HELLA-965453041-Micro-SPDT-Relay/dp/B000VU9A28

That's your issue with the relay. The type eguru referred to have pins on the bottom so they can be soldered to a circuit board and the coils are around 400 ohms. Something like this: https://www.electronicsurplus.com/omron-g5le-14-12vdc-relay-power-spdt-10a-12vdc?_vsrefdom=adwords&gclid=EAIaIQobChMIsuOz_va54gIVaP_jBx06IQgqEAkYBCABEgK_g_D_BwE

redfox90 wrote: As for the transistor I am currently trying to find the correct one for this application and will be trying to wire it as suggested. With just the output and the resistor, and 12v constant power It does light up the led but very very dim. Hopefully the transistor can solve my problem.

Just go with the diagram IAAI posted and you don't even need a resistor because of the placement of the relay coil. It doesn't have to be that transistor as long as it's a PNP. My ex once told me I have a perfect face for radio.

Ok just ordered the relay from the link you posted. Do I wire it up the same as the other relays I’ve tried? Also ordered a pnp transistor and will be trying that as well as a worst case scenario. Will take a few days for me to receive them but I will be posting back with the results as soon as I get them thanks everybody for the help

It'll be similar, but the terminals have different designations. Looking at the datasheet, the coil uses terminals 2 and 5 (instead of 85 and 86). The normally open contacts are 1 and 3 (like 30 and 87). If it has a terminal 4 it is not used (like 87a). If you use a PNP, make sure to note which lead is which. If you ordered one of the part numbers listed in the linked post you should be good to go. Different models may have them oriented differently. If the leads are not clearly indicated on the package, I'd just Google the part number followed by datasheet. Let us know if you need any more help.My ex once told me I have a perfect face for radio.