3rd relay coil is open circuit

Circle denotes coil for relay Number 3 open circuit Test with multi meter all should be the same reading

The two arrow show input and out put of relay

I drilled hole in cover

Then wired in external relay holder

Bypassed As didn't have a RCM in back of van Not pretty but it works Use a normal N/o Relay Contacts 85 and 86 go to the two pins i circled Contacts 87 and 30 go to the input and out put Arrowed Resistor built into board so can use a normal relay

 

Edited your post, please be careful to use "reply" and not "quote"; also, small photos actually work better.
I shrink mine in "Paint" by 66% and even THEN they tend to be too big - both too big to display well AND too big to download quickly.

 

Clever work around solution to a bad RCM. Sometimes parts are not available, cost too much, or take too long to get before the need.

My early career involved servicing and repairing all types of electronic equipment. Before college I went to a vocation/trade school for electronics. I wowed my now wife, and friends when I asked for a paper click and made a temporary repair to their television jumping a sync circuit to another zener diode on the circuit board. I appreciate clever work around solutions.

 

Edited your post, please be careful to use "reply" and not "quote"; also, small photos actually work better.
I shrink mine in "Paint" by 66% and even THEN they tend to be too big - both too big to display well AND too big to download quickly.[/QUOTE]
I do not shrink the size of my photos, I just add them and the site automatically shrinks them to fit, I like big photos as you can see them easier. Downloading is fast, no problem.

 

Won't the relays stay on and burn up?

 

The relay will work exactly the same way the orig does. This has been shown before. James

 

If only there was someone that could replace the old, bad, tired relays to give the RCM new life!

 

Yes, we should try to find someone.

 

I do not shrink the size of my photos, I just add them and the site automatically shrinks them to fit, I like big photos as you can see them easier. Downloading is fast, no problem.[/QUOTE]

The contacts on the RCM should be a looked at regularly before they become a problem.At the first signs of burns they should be replaced, I say that but I never do it. 🙄
I keep a couple of spare relays just for such an occasion. I do keep a spare RCM in the trunk.
A new RCM can be had on eBay for around $120, a bargain.

 

Could you please (1)post a pic of the external relay cover so I can get the exact same one. (2) please show pic of wire connections to back of external relay so I can get feed polarity right.(3)pic shows connections to back of circuit board. Did you leave defunct relay attached in front. Solder joints would infer yes but just want to be sure. Also, the solid silicon diode you referred to in your schematic is a 1N4007. This little baby is what can cause the no crank condition when battery and others are known good. 0.7 v DC drop from 12 v supply across diode is the result based upon manufacturing specs. Also the Blue Gray Black Black Brown resistors on the front of board are 68 ohm resistors just for extra info for the follow forum users

 

Alwyn, just a suggestion, cap off (or tape/clip) the black bare wire. It might be hot and if so while taking it out/testing, that lead may hit a ground. Don't know how it is wired, but if you test it not running or key 'on' (to a ground point) it might be hot.


.

 

follow up to 1N4007 diode comment. The actual total nomenclature on this forward biased diode inside the rcm module is: 1N4007 -935j where 935 J refers to the unit of energy known as a Joule. 1.0 Joule = 1.602176565 x 10-19 =1.0 electron volt meaning that the diode will fail due to heat dissipation when the electrical flow through the diode exceeds 5.835811 volts dc causing the circuit to fail and preventing the car from cranking and starting. The good news. a 1N4007 forward biased diode can be had for under 10 cents. Here is a link: https://www.mouser.com/_/N-1yzvvqx?K...&No=25&FS=True for the diode and here is a link for the replacement relay: https://www.onlinecomponents.com/ame...10618644.html# . Here is the info on the resistors used on the board as well.

 

if you would please. I need a picture of the front of the external add on relay with the embossed wiring diagram that is printed on the actual replacement relay that you plugged in to complete the circuit. thanks

 

Can someone please tell me what relay is what in the rcm. I have the intermittent problem with loosing the speedometer and the bas/abs, esp, and brake lights coming on. I've replaced the conductor plate twice, first with a rock Auto and then with one from needs wings without success. I've also replaced the RCM about 2 years ago with one from Rock Auto as well. I'm using alldata schematics but I don't think it's correct for the relay positions. I have 2 rcms and both relays at the very end look burnt to me and do not turn on when the key is in the run position.

 

I found a video on YouTube. Going to clean up the contact points and hopefully that works.

 

Send them to DJTIGHE for rebuild. It is only about 50.00.

 

I think you already found it, but here's a photo that someone here posted in the past.

 

Thanks, yes I got it. Unfortunately I confirmed it's not the rcm that's the problem.

 

The traction control relay can affect the speedometer and BAS/ESP.
The relay with the burnt contacts is the air pump relay. Common problem.
Both can be fixed with relay replacement. That's what I do.
Email tighed1@hotmail.com if you would like to get your RCM refurbished.

 

For the life of me, I can not figure out why anyone would want to bypass the RCM when such an easy, quick, inexpensive, refurbished RCM is available from tighed1. He does great work for just the cost of repair and it is fast turn around time. Please do not get side tracked with this bypass solution when you can get the job done right by another forum member.
Thank You tighed1 for helping so many!