1991 sv21 faulty starter relay?

[stanaz]

Hi there,

I have a 1991 sv21 (3sfe) which experiences intermittent starting issues (when key is turned nothing happens). Generally If I turn the key on and off about 20 times it eventually starts as per usual. I don't think it is a problem with the starter motor, as this has been replaced a number of times. The battery condition is good, so I don't think this is the problem. I have followed a few other posts which suggest this is not an uncommon problem in the sv21's. Following the circuit diagram in the service manual, I believe the problem may be a faulty starter relay. However I cannot find where it is located to change it. The manual says in the panel on the drivers side wall (beneath the steering wheel), but it doesn't seem to be there.

Is there any alternative locations for the starter relay? Would a faulty relay cause intermittent starting issues (it won't start say once in 20 times)?

Any assistance or ideas would be greatly appreciated. Cheers

[Tard]

I used to get this problem a fair amount on my SV21 when I was younger. Would get stuck at various places and was quite frustrating. Initially I thought it was the starter solenoid but the old man suggested it was either the starter relay or the cable running from it to the starter motor.

Changing the relay first is a good starting point (you should have it in the fuse box in the engine bay), but if that doesn't work, then here is what my experience had been.

My memory on all of this is a little shady unfortunately but if I recall correctly, the cable running to the starter motor had deteriorated over the years and wasn't capable of handling the current. Basically we disconnected the cable from the starter (it was the only cable going to it and the cable connected to a male spade terminal on the starter) and connected this cable to the coil side of a new 30A relay (it plugged straight into the relay). Then we ran some new 8 gauge wire from the positive terminal of the battery to one of the N/O contacts of the relay and then some more 8 gauge wire from the other N/O contact to the spade terminal on the starter. Mounted the relay relatively close to the starter by using cable ties to hold it to some nearby cabling. Fixed the problem immediately.

Edited January 20, 2013 by Tard

[stanaz]

Hi Tard,

Thanks for the advice. I have got myself a 30A fused relay and wire and will give it a go when I get the chance. Appreciate the assistance.

[stanaz]

Here is a follow up on the issue mentioned above.

I followed the advice to bypass the starter relay and replace it with my own 30A relay. I used a fused, 30A automotive relay (4 pin - 85, 86, 87, 30) and positioned it in the engine bay in the far right hand corner, when viewed from the front of the car. I thought this way I would be keeping it away from the heat as best as possible, and also close to the hole in the firewall that I used to pass the wire heading to the ignition block.

Initially I thought I would use my own normally open switch to activate the low current side of the relay so I could avoid tinkering with the wires on the starter block. In the end I thought the added annoyance of needing to use a switch separate to the keys to start the car out weighed the novelty. With the supply wire disconnected from the starter motor (see attached pics) I cycled the key through the three positions (ON, ACC, STR) and noted the voltages on the wires at the back. This trial and error process allowed me to find a wire that went to 12V with the key in STR, was otherwise 0V, and was not being used in the loom. I am not sure why it would be like this, perhaps an additional option not utilised on my car? Anyway, I used this as the supply (low current) positive for the 30A relay, and wired the other side to earth. Then wired the high current side from the battery through the relay to the supply on the starter motor. Worked first time and haven’t experienced any issues since!

Thanks again for the advice. I have added some photos in case anyone else experiences this issue and needs a head start. Note: I found the easiest place to pass a wire through the fire wall was on the left hand side of the car, directly behind the glove box. There was a rubber grommet there which could easily be removed.

[Tard]

Glad to hear it you're issue is solved. For clarification in case anyone comes across this, when I mentioned connecting the cable from the starter directly to the (new) relay coil, I was referring to this one (thanks to your photo):

In my case back when I had the car, the current coming from this cable was sufficient to trigger the relay... just not enough to get the starter motor going. I remember cable tying the relay nearby hanging in open air. Didn't seem to do it any damage, but your solution is just as effective.